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DUIKERS, CABLES, AND NETS: A CULTURAL ECOLOGY
OF HUNTING IN A CENTRAL AFRICAN FOREST
ANDREW J. NOSS
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
UNL LUEF.S iY OF FI.ORIDA LIBRARIES
Andrew J. Noss
This research was assisted by a grant from the Joint
Committee on African Studies of the Social Sciences Research
Council and the American Council of Learned Societies with
funds provided by the Ford, Mellon, and Rockefeller
Foundations. Additional funds were provided by two Grants-
in-Aid of Research from Sigma Xi, The Scientific Research
Society; and by the World Wildlife Fund under the United
States Department of Agriculture Agreement No. 93-G-155.
Many people in many places have contributed their
support to this project. Not all can be named here, nor can
words adequately express the debt that I owe. Most
importantly, I would like to thank my family for sustaining
me: James and Delores Samuels; Philip, Cecilia, Haldor,
Darcy, and Katie Noss; and especially my wife Lauren
Samuels. Their visits to Bayanga were especially uplifting.
I would like to thank my committee members for their
support and guidance, and for allowing me to wander off in
my own direction: my chair Ed Malecki, cochair Abe Goldman,
Nigel Smith, Tom Struhsaker, and Richard Bodmer.
Encouragement from Peter Schmidt, Hunt Davis, and the Center
for African Studies at the University of Florida helped me
decide to embark on this journey in the first place. While
I was writing the dissertation, Tom Struhsaker and Ken
Glander also provided invaluable access to facilities at the
Duke University Primate Center.
In addition to members of my committee, many people
have provided guidance by critically reviewing my research
plans and the dissertation: Serge Bahuchet, Russ Bernard,
Richard Carroll, Gustave Doungoube, Tamara Giles-Vernick,
John Hart, Barry Hewlett, Anna Kretsinger, Cecilia Noss,
Philip Noss, Kent Redford, Gery Ryan, Lauren Samuels, David
Wilkie, and Vivian Wilson.
In the Central African Republic, Mr. Modibo Walidou-
Chahir, Ministre de 1'Enseignement Superieur et de la
Recherche Scientifique generously granted me a research
permit, with the assistance of the Ministry's Chef de
Mission Mr. Remain Sopio. Ambassador Robert Gribbin,
Michael Keller, and Guillaumine Gazembeti at the U.S.
embassy went out of their way to help me obtain the
Richard Carroll first described to me the Bayanga
region and WWF's Dzanga-Sangha project. He and other WWF
staff were continuously supportive and encouraging: in
Washington, Danyelle O'Hara; in Bangui, Doungoube Gustave,
Jean Luabeya, Delphine, Bernardin, Marcel, Frangois, Jean,
and Marc; in Bayanga, Allard Blom, Jean Marc Garreau, Ngaima
Honor&, Yangui Adolphe, Ngatoua Urbain, Victor Babon, and
I would like to thank the people of Bayanga, especially
the hunters who taught me about themselves and the forest,
but who must remain nameless; my assistant Ngbongo Yves; my
helpers Blaise, Elbert, and Bertrand; and my neighbors Mama
Ngounja and her family who looked after me.
I would also like to thank the people of Mossapoula for
sharing part of their lives with me, and for teaching me
about their lives today, no longer just "people of the
forest". In particular I thank Makolea, self-proclaimed
"chef ti gbanda" (the chief of the net hunt), and my
assistant Matofi Fernand.
I also learned a great deal from the other researchers,
whose backgrounds, disciplines, and research topics provided
alternative, thought-provoking perspectives on actors and
events in the Bayanga region: Tamara Giles-Vernick, Michele
Goldsmith, David Harris, Anna Kretsinger, Jay Malcolm,
Justina Ray, Louis Sarno, and Andrea Turkalo. The Peace
Corps volunteers Anthony Aufdenkampe, Bonnie Dixon, John
Hanson, Yann Lussiez, Jo Shrout, Margo Stoddard, and Gillian
Grant did likewise. The hospitality at Dzanga, Koungana,
and Bai Hokou camps was particularly appreciated. Finally,
Jean-Marc and Pierrette Garreau and Allard Blom were also
TABLE OF CONTENTS
LIST OF TABLES .
LIST OF FIGURES .
LIST OF ACRONYMS .
1 INTRODUCTION .
2 CULTURAL ECOLOGY,
AND HUNTING .
. . . 9
Cultural Ecology . .
The Origins of Cultural Ecology
Carl Sauer . .
Julian Steward .
Cultural Ecology in Theory .
Human ecology .
Systems theory .
Ecological anthropology .
Cultural ecology .
Cultural Ecology in Practice
Subsistence economies .
Developing economies .
Cultural ecology themes .
Conservation and Development .
Biodiversity Conservation .
Socioeconomic Development .
Integration of Conservation and
Conservation, Development and Wildlife:
The Role of Hunting .
Hunting Methods . .
Pressure on Wildlife Resources .
Wildlife Management Practices .
The Subsistence Role of Hunting
The Economic Role of Hunting
Conclusion . .
3 THE BAYANGA REGION .
The Ecosystem .
Ecosystem Characteristics .
Species Characteristics .
Atherurus africanus .
Cephalophus callipygus .
Cephalophus dorsalis .
Cephalophus monticola .
Population densities .
Age structure and sex ratios
Ecological interactions .
Estimated Population Densities in
the Bayanga Region .
Line transect surveys .
Net hunt encounters .
Line transect versus net hunt encounter
density estimates .
The Human System . .
Political History . .
Economic and Social History .
Concession system .
Coffee plantations .
Logging . .
Diamond mining . .
Integrated conservation and
Safari hunting . .
Exploitation versus conservation
Population Centers in the Bayanga
Region . .
Bayanga . .
Mossapoula . .
Other settlements .
Ecological Impacts of Human Activities
Human Activities and Habitat Change
Implications of Hunting .
Changes in population structure
Changes in population density .
Sustainable harvest rates ..
Changes in the ecosystem .
I j 1 j
Relations Between the Ecosystem and the Human
System: The Role of Hunting 131
Elephants . ... .131
Hunting Legislation . 135
Bushmeat Markets . 139
Currency Devaluation . ... .143
4 CABLE SNARE HUNTING IN BAYANGA .
Methodology . .
Description . .
Snare Types . .
Snare Hunting Practices .
Snare Hunting Range . .
Impacts of Cable Snare Hunting on Wildli
Captures . .
Age Structure and Sex Ratios .
Wastage . .
Injured Escapes . .
Protected Species . .
Sustainability of Snare Harvest Rates
Economic Importance of Cable Snare Hunting
Employment . .
Income . .
Comparative Data .
Conclusion . .
5 COMMUNAL NET HUNTING IN MOSSAPOULA
Methodology . .
Description . .
Communal Net Hunting Practice .
Beliefs and Rituals .
Seasonality . .
Mossapoula Net Hunting Range
Impacts of Net Hunting on Wildlife .
Captures . .
Age Structure and Sex Ratios .
Vulnerability . .
Sustainability of Net Hunting Harvest
Economic Importance of Net Hunting 240
Time Allocation to Net Hunting .. .241
Returns from Net Hunting . 252
Role of Women in Net Hunting . 262
Forest Hunting Camps . 265
Comparative Data . 272
Conclusion . . 281
6 COMPARISON OF BAYANGA CABLE SNARE HUNTING AND
MOSSAPOULA COMMUNAL NET HUNTING 286
Impacts on Wildlife . ... .286
Captures . . 287
Sustainability . ... .291
Economic Importance .. . 296
Employment and Time Allocation 297
Returns . . 298
Conclusion . . 302
7 HUNTING AND CHANGE: INTEGRATING CONSERVATION
AND DEVELOPMENT? . 303
Hunting and Cultural Ecology . 303
The Ecosystem . 304
The Human System . 305
Hunting and Change . 308
Biodiversity Conservation . 313
Socioeconomic Development . .. 316
Integrated Conservation and Development 320
Recommendations for Conservation and
Development, with Particular Reference
to the Dzanga-Sangha Project .. .326
Monitoring . . 327
Snare Hunting . 329
Net Hunting . . 332
Recommendations for Further Research 334
1 WILDLIFE SPECIES NAMES .
2 GAME SPECIES CHARACTERISTICS .
3 SUSTAINABLE HARVEST RATES .
4 WILDLIFE SPECIES BY CAPTURE METHOD AND
PROTECTION STATUS . .
5 OBSERVATION OF SNARE HUNTING .
6 BAYANGA SNARE AND GUN HUNTING OFFTAKES
7 OBSERVATION OF COMMUNAL NET HUNTING .
8 FOODS COMMONLY GATHERED BY NET HUNTERS
BIBLIOGRAPHY . .
BIOGRAPHICAL SKETCH . .
LIST OF TABLES
3.1 Game Species Activity, Weight, and Diet 66
3.2 Population Densities for Game Species at
Research Sites in Gabon, Zaire and
Cameroon . . 70
3.3 Age Structure for C. Monticola ... .71
3.4 Estimated Population Densities from Line
Transects . ... .77
3.5 Estimated Population Densities from Net Hunt
Encounters . . 79
3.6 Comparative Density Estimates: Line Transects
versus Net Hunt Encounters in a
Single Area . 88
3.7 Population Densities of Game Species in the
Bayanga Region and Elsewhere 89
3.8 Estimated Population Figures for Settlements
in the Bayanga Region ... .108
3.9 Bayanga Population Origins .. 109
3.10 Men's Employment in Bayanga .. 112
3.11 Mossapoula Censuses . .. 115
3.12 Impacts of Hunting on C. monticola:
Age Classes in Hunted versus Unhunted
Populations .. . 126
3.13 Sustainable Harvest Rates . .. 129
3.14 Head Tax Levied on Game Species .. 137
3.15 Observed Bushmeat Sales by Species 142
4.1 Observed Cable Snare Captures ... .162
4.2 Reported Cable Snare Captures .. 165
4.3 Capture Rates for Fence Snares .. 166
4.4 Capture Rates for Foot and Neck Snares 166
4.5 Age Structure of Animals Captured in Snares .167
4.6 Sex Ratios of Animals Captured in Snares 168
4.7 Wastage from Cable Snares . .. 169
4.8 Injured Escapes from Cable Snares .. .171
4.9 Snare Injuries on Captured Animals ... .173
4.10 Annual Biomass Harvest by Snares and Guns 177
4.11 Bayanga Annual Snare Harvest Rates 178
4.12 Bayanga Annual Snare and Gun Harvest Rates 180
4.13 Sustainability Index by Species and
Hunting Method . .. 180
4.14 Bushmeat Market Prices in Bayanga .. 188
4.15 Weekly Returns from Snare Hunting .. 189
4.16 Annual Bayanga Bushmeat Production ... .191
4.17 Comparative Bushmeat Consumption .. .194
4.18 Comparative Snare Captures .. 195
4.19 Comparative Annual Snare Hunting Returns 196
4.20 Comparative Snare Hunting Yields 197
5.1 Descriptive Statistics for Mossapoula
Net Hunts . 207
5.2 Reasons Cited for not Net Hunting .. 218
5.3 Net Hunting Pressure within Mossapoula
Hunting Range . .. 225
5.4 Net Hunt Captures . .. 227
5.5 Net Hunt Captures by Method .. 228
Net Hunt Captures by Women versus Men .
Descriptive Statistics for Forest Camp (N=8)
versus Day Hunts (N=73) .
Net Hunt Yields from Forest Camp Hunts (N=8)
versus Day Hunts (N=73) .
Comparative Net Hunt Statistics .
Comparative Net Hunt Captures .
Hunting Yields and Distance from Town .
Net Hunt Capture Rate .. ... 229
Age Structure of Net Hunt Captures .. .230
Sex Ratios of Net Hunt Captures .. 231
Vulnerability to Net Hunting by Species 232
Mossapoula Annual Net Hunt Harvest Rates 236
Sustainability Index by Species for
Net Hunt Harvests . .. 237
Annual Biomass Harvest by Mossapoula
Net Hunters . 238
Effects on Net Hunting Yields of
Releasing Young, Female, or
Pregnant/Lactating Animals .. 240
Mossapoula Individual Activity
Distribution . .. 244
Mossapoula Community Activity
Distribution . 245
Activity Distribution by Age Group 249
Net Hunt Returns . .. 255
Mossapoula Weekly Net Hunt Returns 257
Annual Net Hunting Returns .. 258
Annual Mossapoula Bushmeat Production 261
Species Captured by Snares versus Nets
Animals Captured by Snares versus Nets
Sex Ratios of Animals Captured by Snares
versus Nets . .
Harvest Rates by Snares and Nets .
Sustainability Index by Species and
Hunting Method . .
Age Structure of Snare and Net Captures
Weekly Returns per Hunter: Snares
versus Nets . .
Returns per Person/Day Hunting: Snares
versus Nets . .
Variation in Bushmeat Prices .
Annual Bushmeat Production by Snares and
Nets, and Bayanga Beef Sales ..
LIST OF FIGURES
2.1 Theory in Geography and Anthropology .. 10
2.2 A Systems Model of Human Ecology 18
3.1 The Central African Republic and the
Research Area . 57
3.2 Average Temperatures (oC): Bayanga,
1974-1984 . ... .59
3.3 Average Rainfall (mm): Bayanga, 1973-1984 .60
3.4 Vegetation of the Bayanga Region 61
3.5 Location of Line Transect and Net Hunt
Surveys . ... .75
3.6 Population Densities of Game Species: C.
monticola, A. africanus, C. dorsalis
and C. callipygus .. 83
3.7 C. monticola Population Densities from
Net Hunt Encounters . ... 84
3.8 A. africanus Population Densities from
Net Hunt Encounters .. 85
3.9 C. callipygus Population Densities from
Net Hunt Encounters . 86
3.10 C. dorsalis Population Densities from Net Hunt
Encounters . 87
3.11 Logging in the Bayanga Region . 98
3.12 Dzanga-Ndoki National Park and Dzanga-Sangha
Special Reserve . .. 101
3.13 Population Centers in the Bayanga Region .106
Bayanga Residential and Occupational
Mobility . .
Mossapoula Censuses: September, 1993 and
November, 1994 . .
Mossapoula Residential and Occupational
Mobility . .
Bayanga Snare Hunting Camps and
Snare Lines . .
Bayanga Snare Hunting Range .
Relative Distribution of Snare Captures and
Abundance for Primary Game Species .
Informant Occupation Time-Lines .
Net Hunt Leaders . .
Mossapoula Net Hunting Range .
Mossapoula Hunting Range Decline .
Species Vulnerability to Net Hunters .
Community Participation in Net Hunting
Individual Participation in Net Hunting
Time Allocation to Net Hunting .
Net Hunting Participation Rates by
Age Group . .
Time Allocation to Net Hunting by
Age Group . .
Annual Returns from Net Hunting
(kilograms) . .
Annual Returns from Net Hunting
(CFA francs) . .
Time Spent in Forest Camps .
Location of Mossapoula Forest Camps .
LIST OF ACRONYMS
BSP Biodiversity Support Program
CAR Central African Republic
CFA Communaut6 Financiere Africaine
COICA Coordinadora de las Organizaciones Indigenas de la
EIL Experiment in International Living
ICDP Integrated Conservation and Development Project
IUCN International Union for the Conservation of Nature
USAID United States Agency for International Development
WCED World Commission on Environment and Development
WCED World Commmission on Environment and Development
WCS World Conservation Strategy
WRI World Resources Institute
WWF World Wildlife Fund and World Wide Fund for Nature
Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
DUIKERS, CABLES, AND NETS: A CULTURAL ECOLOGY OF
HUNTING IN A CENTRAL AFRICAN FOREST
Andrew J. Noss
Chairman: Dr. Edward J. Malecki
Major Department: Geography
This dissertation analyzes the relationships between
ecological and human systems, and between biodiversity
conservation and socioeconomic development, by focusing on
the role of hunting. The analysis addresses two research
questions. First, how does hunting affect wildlife
populations? Are harvests sustainable? Second, what is the
economic importance of hunting, relative to other economic
activities, for human populations?
The two primary hunting methods in the rainforests of
the south-western Central African Republic are cable snare
hunting by immigrant ethnic groups, and communal net hunting
by BaAka Pygmies. Data collection is based on participant
observation, activity records, interviews, market surveys,
and biological measurements of captured animals.
The primary game species for both hunting methods are
the brush-tailed porcupine Atherurus africanus and the
duikers Cephalophus monticola, C. callipygus, and C.
dorsalis. Net hunters encounter and capture few other
species. But virtually all mammalian species, as well as
several birds and reptiles, are captured by snares.
Net hunters probably overexploit C. monticola and C.
dorsalis, whereas snare hunters probably overexploit C.
callipygus. Both hunting methods are practiced in most
areas, in addition to gun hunting. Therefore current
hunting by all methods combined is probably excessive for
all game species. In addition to animals killed and
recovered by hunters, snares lose many animals to
decomposition and scavengers, and many others escape with
Although both hunting methods produce meat for
subsistence and for sale in local markets, snare hunting is
primarily market-oriented, while net hunting is primarily
subsistence-oriented. Both groups of hunters pursue mixed
subsistence and economic strategies, combining hunting with
Human populations are increasing through population
growth and immigration, while economic expectations are
rising. At the same time, hunting ranges are declining as
other land use systems expand. Wildlife is an open access
resource belonging to the state. Local hunters do not
conserve or manage wildlife resources: they believe that
wildlife cannot be exterminated by snares or nets. Even if
wildlife is exterminated they will pursue other activities
or move elsewhere. Under these conditions, conservation and
development are incompatible.
This dissertation analyzes the relationships between
ecological and human systems by focusing on an activity
which links the two systems, namely wildlife exploitation.
Cultural ecology provides the theoretical framework for the
analysis. Accordingly, two parallel topics are defined.
The first topic relates to the ecosystem, in particular the
theory and practice of biodiversity conservation. Of
primary interest from a conservation perspective are the
impacts of hunting on wildlife and the sustainability of
wildlife harvesting. The second topic relates to the human
system, and the theory and practice of socioeconomic
development. Of primary interest from a development
perspective is the economic importance of wildlife
exploitation, as well as the relations between hunting and
other subsistence or economic activities. Each chapter
addresses both themes and explores the links between the
The research context is the Bayanga rainforest region
of the south-western Central African Republic (CAR). The
local population consists of several ethnic groups,
including both long-term local residents and recent
immigrants. Current economic activities in the region are a
continuation of historical resource exploitation and land
use patterns: logging, diamond mining, and coffee
plantations. In addition, people engage in cultivation,
fishing and hunting for economic and subsistence purposes.
The most recent regional development is the creation of a
national park to conserve a portion of CAR's remaining
forests and wildlife.
Research depends primarily on participant observation
of legal and illegal hunting activities. Additional data
are collected through activity records, interviews, market
surveys, and biological measurements of captured animals.
These methodologies generate two types of data: first,
ecological data regarding the wildlife resource base and the
impacts of exploitation on wildlife populations; and second,
economic data on the role of wildlife exploitation in the
Chapter 2 locates the research in the context of
geographical and anthropological theory, specifically in
cultural ecology. In addition, the chapter relates the
research to the literature on biodiversity conservation and
socioeconomic development, and on efforts to integrate the
two. The section concludes by examining the relations
between hunting, on one hand, and both conservation and
development on the other.
Chapter 3 describes the ecosystem and the human system
in the research area. The ecosystem, like other tropical
rainforests, is complex. This section describes in
particular the resource base represented by the four primary
game species: the brush-tailed porcupine Atherurus
africanus, and the duikers Cephalophus callipygus, C.
dorsalis, and C. monticola. Of particular importance are
estimated population densities of these game species in the
Bayanga region, and predicted sustainable harvesting rates.
Components of the human system include political
authorities, economic activities, and population centers.
Change in each of these components over time in turn affects
patterns of wildlife exploitation. In order to illustrate
the influence of hunting on relations between the ecosystem
and the human system in the Bayanga region, the chapter
concludes by discussing the following cases and issues: the
ecological impacts of human activities, elephants, hunting
legislation, bushmeat markets, and currency devaluation.
Chapters 4 and 5 analyze the two primary local hunting
methods--cable snare hunting and communal net hunting
respectively--practiced by two distinct groups of hunters.
In each chapter, a description of the research methodology
and the hunting method precedes a discussion of the primary
1) What are the impacts of the hunting method on
wildlife in terms of species distribution, sex ratios,
and age classes captured or injured? Is current
offtake by the method sustainable?
2) What is the economic importance of the hunting
method in terms of employment, time allocation, and
returns? What is the relationship between hunting and
other subsistence and economic activities?
Chapter 4 examines cable snare hunting by Bayanga
residents of several ethnic groups, based on participant
observation of snare hunting trips from September 1993 to
December 1994. Most snare hunting requires overnight trips
to check snare lines. Cable snares are illegal everywhere
in CAR because they are indiscriminate in capturing and
injuring virtually all mammals, as well as several species
of birds and reptiles. But many people depend on snares to
obtain food, as well as income from the sale of meat in
local markets. Cable for snares is much easier and cheaper
to obtain than the alternative--firearms. Snare hunting can
be a full-time occupation for weeks or months, though
Bayanga residents prefer formal employment.
Chapter 5 examines communal net hunting by the BaAka of
Mossapoula, based on participant observation of net hunts
from September 1993 to November 1994. Most net hunts are
day trips from Mossapoula, while in other cases groups hunt
from temporary camps established in the forest. Net hunting
is legal outside protected areas, and targets the most
abundant small/medium-sized terrestrial mammals--the
porcupine and duikers mentioned above. Net hunting also
provides food and income, but is one of several subsistence
and economic activities among which Mossapoula residents
alternate on a daily basis.
Chapter 6 compares the two hunting methods, in terms of
their implications for the ecosystem and the human system.
Chapter 7 concludes by reviewing the role of hunting within
the cultural ecology framework. The chapter also addresses
the implications of hunting for biodiversity conservation
and socioeconomic development across tropical forests, and
proposes recommendations for further research.
The following comments are general explanatory notes on
the text and the fieldwork.
BaAka: I use the general term "Aka" which unites the
Bayanga area Aka with those in the Lobaye area of CAR and
those in northern Congo, all of whom share a single
language. The Aka have been extensively studied by Serge
Bahuchet and others. Other terms in the literature for the
same people are "Biaka," "Babinga," and "BaMbenga." Louis
Sarno's (1993) more local term "BaBenzele" refers to the
Bayanga region BaAka. The BaAka are linguistically and
culturally distinct from the Baka of Cameroon and CAR west
of the Sangha river. When discussing the residents of
Mossapoula, I refer only to the BaAka residents.
Pygmy: The BaAka are one of several African forest
peoples, traditionally hunter-gatherers, known as "Pygmies."
The term refers to their small stature, and dates back to
Aristotle, Herodotus, Homer and Pliny (Demesse, 1978). When
referring to particular ethnic groups, I use the name the
group calls itself--Aka, Efe, Mbuti, etc. I have found no
alternative that refers to these groups collectively.
Bilo: I use the BaAka term "Bilo" to refer
collectively to all non-BaAka ethnic groups in the Bayanga
region (Kisliuk, 1991; Kretsinger, 1993). Other terms used
in the literature to refer to Pygmies' neighbors are not
accurate in the Bayanga context. The term "Bantu" is
incorrect, as several ethnic groups such as the Gbaya are
not Bantu-speaking, while Aka is a Bantu language (Bahuchet,
1985c; Bahuchet and Thomas, 1986; Greenberg, 1966). The
terms "villagers" and "farmers" no longer provide meaningful
distinctions where the BaAka too live in villages and
cultivate farms. When discussing Bayanga residents, I refer
only to Bilo residents.
Orthography: In the case of river and town names, I
use the French orthography for consistency with other maps
produced for CAR. In the case of personal names and words
in African languages, I use basic phonetic orthography.
Languages: I spoke Gbaya and fluent French before
beginning my research, and learned Sango during my
fieldwork. I did not learn the BaAka language, and this
constrained my data collection with those BaAka individuals
who do not speak Sango (in particular older women), although
my assistants served as interpreters. Because I worked with
Bilo as well as BaAka informants, Sango was the more useful
language to learn.
Assistants: Throughout my fieldwork I employed two
assistants: Ngbongo Yves from Bayanga, and Matofi Fernand
from Mossapoula. In addition, I hired two other Bayanga
residents to conduct surveys: Ndombe Blaise for a
neighborhood bushmeat market survey, and Bopokina Elbert for
a public market survey.
Informant compensation: The issue of compensation was
problematic throughout my fieldwork. In particular, I did
not want to provide material or financial rewards that would
encourage individuals to hunt more than they might
otherwise. Therefore, I did not provide daily rewards, but
several times during the course of my fieldwork purchased
clothes and shoes for informants to thank them for their
assistance. With respect to Bayanga snare hunting, my
informants were the 16 individual hunters that I
accompanied. With respect to Mossapoula net hunting, my
informants were all 246 adult and adolescent BaAka
residents, including those who rarely or never net hunted.
"The project": Throughout the dissertation I use this
term to refer to the integrated conservation and development
project described in Chapter 3. The project is administered
by the World Wildlife Fund, is headquartered in Bayanga, and
manages the Dzanga-Sangha Special Reserve and Dzanga-Ndoki
"The logging company": I use this term to refer to the
sawmill located in Bayanga. Since 1972 three different
logging companies--Slovenia Bois, Sangha Bois, and Sylvicole
de Bayanga--have used this sawmill to exploit timber in the
Bayanga region (see Chapter 3).
CFA francs: The currency of the Central African
Republic is the Communaut6 Financiere Africaine (CFA) franc,
pegged at an exchange rate of 1 French franc = 50 CFA
francs, or $US1 290 CFA francs, until January 1994. At
that time the CFA franc was devalued to a new pegged
exchange rate of 1 French franc = 100 CFA francs, or $US1
580 CFA francs. See Chapter 3 for a discussion of this
CULTURAL ECOLOGY, CONSERVATION, DEVELOPMENT AND HUNTING
This chapter begins by examining the theoretical
context for the research within the fields of geography and
anthropology, and particularly in the field of cultural
ecology. The chapter in turn relates the research to the
literature on biodiversity conservation, socioeconomic
development, and efforts to integrate the two. The
concluding section examines the relations between hunting on
one hand, and both conservation and development on the
other, in case studies across the tropics.
This section reviews the development of the field of
cultural ecology, particularly through the work of Carl
Sauer and Julian Steward. Cultural ecology is further
described by examining other research in the field.
Cultural ecology integrates geography's people/
environment tradition with anthropology and ecology (Figure
2.1). The resulting theoretical framework considers the
systemic interdependency between society and nature. People
affect the environment and natural ecosystems by
appropriating natural resources and integrating them into
production processes--whether at the household, community,
or global levels. The natural environment in turn affects
social structures and culture as well as subsistence and
economic production systems.
Man/land or people/environment tradition Ecology
--cultural materialism <
Figure 2.1: Theory in Geography and Anthropology
Note: The following components of this figure are described
in greater detail below: human ecology, systems theory,
ecological anthropology, cultural materialism, and political
The Origins of Cultural Ecology
The fathers of cultural ecology are the geographer Carl
Sauer and the anthropologist Julian Steward.
Carl Sauer introduced the concept of culture to
geography in the United States, by defining human geography
as cultural history (Leighly, 1976). He saw landscape as a
cultural text (Cosgrove and Jackson, 1987): cultureue is
the agent, the natural area is the medium, and the cultural
landscape the result" (Sauer, 1925, p. 46). Thus, humans
transform natural landscapes into cultural landscapes
through the action of cultural forms such as population and
settlement patterns, land utilization systems, subsistence
systems, and communication systems (Parker, 1981; Sauer,
1941a; 1944; 1962a; 1963a; 1963b).
Sauer set the stage for the development of cultural
ecology. Most importantly, he described landscape as an
association of physical and cultural forms; a changing,
living scene where human activities unfold. He described
relationships between resources in the environment and
cultural forms. He emphasized the impacts of humans on the
environment, and the influences of the environment on human
activities (Sauer, 1925). For example, humans alter
habitats through settlement and agriculture, and they affect
particular species through domestication, dispersal, and
extinction (Sauer, 1941a; 1963b). At the same time, humans
adapt to the physical environment by organizing their lives
around the natural resources that their skills and values
identify (Gade, 1988; Sauer, 1941b; 1962a, 1962b).
The anthropologist Julian Steward founded the field of
cultural ecology by integrating natural systems and cultural
systems into a single analytical framework. The framework's
three essential components are resources, technology, and
labor. Resources are determined by culture: only human
knowledge and technology make resources accessible (Murphy,
1977). Technology is a cultural trait, while the
application of labor is determined by cultural elements
including economic arrangements, social organization, and
demography (Orlove, 1980).
Based on these components, cultural ecology addresses
four principal topics: 1) the relations between the
environment and exploitation or production technologies; 2)
the behavior patterns resulting from appropriation and
production systems in a particular area using particular
technologies; 3) the effects of these behavior patterns on
other aspects of culture; and 4) the impacts on culture and
the physical environment of relations with other ethnic
groups and external institutions (Steward, 1955; 1968).
Cultures and social structures thus adapt not only to the
physical environment, but also to the social environment.
Steward defined a "culture core" as the central causal
mechanism influencing other aspects of culture. This
culture core included the cultural features most closely
connected to exploiting the environment, namely those
associated with subsistence systems and economic
arrangements (Moran, 1982). The environment only influences
the culture core, while more peripheral aspects of culture
and social organization including political and religious
patterns are subject to autonomous processes of cultural
history (Murphy and Steward, 1956; Steward, 1950; 1955).
Cultural Ecology in Theory
Cultural ecology developed in opposition to
environmental determinism, which emphasizes the empirical
physical environment as the primary factor that determines
human behavior and culture in general (Johnston, 1986;
Nugent, 1981). Instead, cultural ecology favors Franz Boas'
possibilism, in which the environment defines a set of
opportunities and limits among which people make choices to
attain goals (Brookfield, 1969; Moran, 1982). Cultural
ecology follows geography's people/environment or man/land
tradition, within the broader field of human ecology
(Ackerman, 1963; Kates et al., 1990; Stoddart, 1987).
Human ecology developed in the early 1900s among
sociologists who borrowed the ecosystem concept from
biologists to describe the social system as a human
ecosystem in which humans organize to maintain themselves in
a given environment. An ecosystem is a set of organisms
within a physical environment that has spatial dimensions.
Ecology is the study of the biological, physical, and human
components in an ecosystem, and of their interactions
through energy flows and nutrient cycles (Kormody, 1974;
Human ecology is the process of forming viable
relations between population and environment. The emphasis
is on individuals and populations as biological entities
profoundly modified by culture. These entities affect and
are affected by the environment and each other. The
environment includes natural and human-modified biological
and physical elements as well as the cultures of peoples in
adjacent areas and beyond: the components impinge on one
another (Hawley, 1986). In the form of institutional
systems such as market and administrative forces, production
systems, and pressure groups, culture mediates between
humans and the biophysical environment (Barrows, 1923;
Carlstein, 1982; Smith and Reeves, 1989). Thus settlement
patterns and subsistence strategies reflect social behavior,
technology, resource opportunities and limitations, as well
as external and internal stimuli (Butzer, 1982; Helm, 1962;
Morrill, 1987; Porter, 1978). Some theorists describe human
ecology simply as human behavior: culture is therefore the
ecological equivalent of animal behavior (Bennett, 1990;
Rappaport, 1984; Vayda and Rappaport, 1968).
Systems theory, like ecology, provides a method for the
holistic analysis of human situations, rather than a theory
that permits rigorous problem selection (Brookfield, 1982;
Ellen, 1982). Generally speaking, a system is a framework
for describing and analyzing a complex array of unlike
variables that interact through connectivity, mutual
causality, and feedback (Butzer, 1990; Morren, 1986).
Systems analysis emphasizes the functions and interchanges
of component parts, through flows of energy, materials, and
information that can be quantified (Micklin, 1984; Odum,
1983; Rambo, 1982a; 1983; Sponsel, 1989). All interactions
are interdependent (Butzer, 1989). Systems theory enhances
the ecological framework of cultural ecology analysis
because it integrates environmental and human variables
However, it may be impossible to quantify certain
factors, particularly external factors that are significant
in an open system (Butzer, 1990; Ellen, 1982). For example,
socio-political and ideological factors must be included in
the analysis because the environment and technology are not
sufficient to explain contemporary ecosystem realities
(Parker, 1981; Orlove, 1980).
Ecological anthropology and cultural ecology both
emphasize culture as a means of adapting to the environment
(Headland, 1986; Jochim, 1981; Parker, 1981), and both
examine the interactions of human populations with other
components of the local ecosystem and with external
influences (Helm, 1962; Moran, 1981a). Systems of
production are important links between population dynamics,
social organization, culture, and the environment (Orlove,
However, ecological anthropologists emphasize the
evolutionary nature of human adaptive strategies, including
sociocultural as well as physiological responses to problems
and stresses imposed by the local environment (Morren, 1986;
Orlove, 1980; Parker, 1981). Alternatives can be compared,
and overall success in human adaptability can therefore be
measured according to demographic, energetic, and
nutritional criteria (Moran, 1982).
Adaptive strategies include demographic shifts through
migration and changes in settlement patterns, socioeconomic
relations with other groups through trade links, and culture
traits like technology (Gross et al., 1979; Moran, 1982;
Morren, 1986; Tanaka, 1980). In addition, current adaptive
strategies are strongly influenced by regional level factors
including the goals of national and international actors
regarding production, conservation, and development at the
regional scale (Moran, 1981a).
Like human ecology, cultural ecology is defined
generally as the systemic relations between society or
social systems on the one hand, and nature or ecosystems on
the other (Butzer, 1989; Grossman, 1977; Moran, 1981a;
Turner, 1989). More specifically, cultural ecology refers
to the adaptation of human society to the local environment
through the flexible agent of culture (Bahuchet, 1985b;
Baksh, 1984; Butzer, 1990; Clarkson, 1968; Knight, 1992).
The local environment includes not only natural resources,
but also other human groups that influence adaptation
(Barth, 1969; Campbell, 1983; Netting, 1968; Sponsel, 1986).
Carl Sauer examined the results of human-environment
interactions visible in landscapes (Parker, 1981). Cultural
ecologists more recently have focused on the processes of
change. They argue that culture does not simply adapt to
environmental constraints or changing environmental
conditions: feedback processes between culture, technology
and nature alter the natural environment as well as the
human environment (Bargatsky, 1984; Bennett, 1976; Headland,
1986; Nowicki, 1985). People alter the habitat to make it a
more suitable place to live, while also making themselves
more suitable to live in that habitat (Denevan and Schwerin,
1978). Cultural ecology therefore describes the human use
of resources, and the human appropriation of nature
Steward's cultural ecology has been criticized for
treating culture and environment as separate and opposed
entities, lacking the concept of dynamic mutually
interacting processes (Moran, 1990). In the 1960s cultural
ecologists refocused the field on the ecosystem as a unit of
analysis (Ellen, 1988). Nature and culture came to be seen
as two interlocking subsystems of a larger system (Figure
2.2) in which relations among components are circular
(Bennett and Chorley, 1978; Mikesell, 1978; Rambo, 1982).
Within the larger system, cultural ecology emphasizes the
predominant role of culture in mediating change and
governing feedback relationships (Sponsel, 1980).
Nevertheless, the ecosystem interacts with every component
of the culture system, and determines a set of freedoms and
constraints within which individuals exercise choice
(Parker, 1981; Sponsel, 1986).
Figure 2.2: A Systems Model of Human Ecology
Source: Rambo, 1983, p. 26. Reprinted with permission of
the author, A.T. Rambo.
The ecosystem concept has been criticized for
neglecting the critical role of external factors such as
larger economic and political systems, as well as the
historical background of contemporary environmental
circumstances. Defining ecosystem boundaries is also
problematic. Furthermore, ecosystem analyses tend to
emphasize long-term homeostasis and ignore changes taking
place in local ecosystems. Finally, they overlook diversity
and differentiation within local groups or populations, and
the options people have in adjusting to change (Lees and
Bates, 1990; Moran, 1990; Orlove, 1980).
Cultural Ecology in Practice
Cultural ecology has addressed a variety of topics in a
wide range of human societies. Given the critiques
described above, cultural ecologists have used a variety of
methods that identify particular subsystems or problems for
analysis, or that emphasize particular components of the
Cultural materialism. Cultural materialism gives
primacy to the technological and economic components of the
cultural system, as they relate to modes of production and
reproduction (Abruzzi, 1980; Micklin, 1984; Sponsel, 1983).
These elements of social organization and culture are
practical adaptations permitting a particular population to
exploit its environment successfully (Harris, 1966; 1974;
1977). Like ecological anthropology, this field focuses on
population as a unit, and on biological concepts such as
carrying capacity, nutrient flows and energy cycling
(Orlove, 1980; Rappaport, 1984).
Political ecology. Political ecology emphasizes the
influence of political and social ideologies as well as
economic processes on the interactions of society and the
environment through the organization of labor, space, and
resources in the system of production. Exogenous political
and economic forces, as well as the internal structure of
society governing access to resources and modes of
production, condition local ecosystem-human system
interactions (Bassett, 1986; 1988; Bell and Roberts, 1991;
Hecht and Cockburn, 1989; Hyndman, 1994; Knight, 1992;
Pickles and Watts, 1992; Schmink and Wood, 1987; Watts,
Because of the practical difficulties involved in
analyzing all the components of ecosystem-human system
relationships, cultural ecologists have focused on
relatively small, isolated, and homogeneous systems in which
cultural institutions tend to be dominated by subsistence
activities (Fosberg, 1976; Headland, 1986; Mikesell, 1978;
Porter, 1978). Although relations with the physical
environment are particularly direct, impacts on the
environment are minimal (Bennett, 1976; Rambo, 1983).
Subsistence systems represent a means of regulating
energy flows between the human population and the ecosystem
(Nietschmann, 1984). Research in cultural ecology describes
how these societies exploit and alter their environment
through hunting, gathering, fishing, and agriculture
(Bahuchet, 1972; 1978; 1979a; 1979b; 1985b; Dornstreich,
1977; Marks, 1976; Nietschmann, 1971; 1973; Smole, 1962;
Vickers, 1979). Cultural ecology further examines cultural
adaptation to environmental constraints, for example to
argue that the lack of animal protein causes people to
establish complex food prohibitions to protect certain game
animals (Ross, 1978). Shifting agriculture also represents
an adaptation to environmental constraints such as poor soil
fertility, and abundant weeds and pests, as well as to
socioeconomic constraints such as scarce labor and
inefficient technology (Denevan, 1978). Finally, ecological
change can induce social change: the depletion of forest
resources results in more intensive exploitation, and the
dispersal of human settlements (Baksh, 1984; 1985).
Many subsistence societies in tropical forests adapt to
their environment by maintaining trading relationships with
neighboring societies. In its simplest manifestation, one
group exploits forest resources such as wild animals, while
the other cultivates food crops, and the meat-for-starch
exchange provides both groups with both products (Headland
1986; 1988; J. Peterson, 1977; 1978a; 1981; Terashima,
1986). Thus, dynamic relations with neighboring groups are
key factors influencing settlement patterns, mobility, and
even hunting techniques (Bahuchet, 1978; Endicott, 1979;
1984; Harako, 1981; Hoffman, 1988; Rambo, 1979a; 1982b).
Recent studies argue that the choice of foraging strategy is
an outcome of social and economic pressure by neighboring
groups (Eder, 1988b; Sellato, 1994).
In the case of more complex human-environment systems
with links to external political and economic forces,
researchers have focused on particular subsystems, in
particular agricultural subsystems (Brookfield, 1969;
Clarkson, 1968; Netting, 1968; 1986; Rambo, 1982a). The
systemic relationships incorporated in the analysis have
expanded to include not only the natural environment and
subsistence production, but also commodity production, the
social relations of production, cultural values, and
political and economic forces (Grossman, 1984). Others
emphasize the "human ecosystem" comprising four components
linked by systems of production: population dynamics,
social organization, culture, and environment (Headland,
1986). Finally, cultural ecologists have studied cultural
methods and institutions for regulating and managing natural
resources, such as fisheries, wildlife, forests, etc.
(Nietschmann, 1973; 1984).
Alternatively, one may begin with a particular human-
environment problem, and contextualize relations within
progressively wider or denser contexts (Vayda, 1983).
Similarly, Lees and Bates (1990) advocate beginning with a
specific environmental event and analyzing environmental
change and human behavior in response to this event. These
methods apply cultural ecology by examining the effects of
economic and social organization on the ecosystem, and the
impact of environmental change on socioeconomic systems.
But they do not depend on predetermined units of analysis or
specific system boundaries.
Cultural ecology themes
As described above, cultural ecologists analyze the
food base, activity patterns, group composition, resource
availability, relations with other groups, and change over
time in all these variables. Food production is considered
to be the primary human/environment nexus, and cultural
ecologists emphasize the coevolution of subsistence
strategies and certain features of the environment
(Bargatsky, 1984; Ellen, 1988; Knight, 1992; Mikesell,
1978). They identify environmental constraints and analyze
patterns of social adaptation to cope with change in
ecological and social systems (Butzer, 1990; Durham, 1976).
For example, in the context of Brazil's Transamazon
settlement scheme, which has significantly altered the
tropical forest, colonists must adapt to both ecological
constraints such as low soil productivity as well as
socioeconomic constraints such as limited access to
transportation and markets (Denevan, 1973; 1989; Smith,
In addition to local environmental and socioeconomic
constraints, institutions at the regional, national, and
international levels determine the nature of interactions
between people and the environment (Marks, 1989; Moran,
1979; 1993; Riddell, 1988). Thus the growth of extractive
industries and commercialization in Brazil has in many
places replaced Indian culture with caboclo culture, as
people opportunistically respond to new resources and new
environmental and socioeconomic constraints and
opportunities. They adapt through technological,
institutional and organizational change (Dove, 1993b; 1994;
Hardesty, 1986; Kates, 1987; Parker, 1981).
New economic systems thus offer new opportunities,
subject to new constraints such as limited land availability
and rising population density. Subsistence societies may
exploit new resources, adopt cash crops, and engage in non-
agricultural activities (Denevan and Schwerin, 1978;
Grossman, 1981; 1984; Nietschmann, 1972; 1973). Ecological
systems facilitate as well as limit human action, while
resource exploitation using particular technologies imposes
short-term and long-term effects on social and natural
systems (Smith, 1976a).
Cultural ecologists are also interested in traditional
resource use and management institutions as potential models
for development schemes in the Third World (Bennett and
Dahlberg, 1990; Butzer, 1989; Eden, 1978; Marks, 1984;
Nowicki, 1985; Sponsel, 1985; 1986). Other general topics
include the following: environmental and regional planning,
environmental constraints to development, the relations
between environmental potentials and economic opportunities,
the consequences of shifting from a subsistence to a market
economy, sedentarization, intensification of production,
land use and tenure, and tourism studies (Bennett, 1976;
Ellen, 1988; Hardesty, 1986; Knight, 1992; Mabogunje, 1984;
Mikesell, 1978; Murphy and Steward, 1956; Porter, 1978;
Rambo, 1982a). The following chapters address many of these
topics through a case study of wildlife exploitation,
linking hunting in the Bayanga region to wider ecosystem and
human system causes and effects.
Conservation and Development
The relationship between hunting and the ecosystem is
particularly important with respect to biodiversity
conservation: hunting directly reduces wildlife
populations, and excessive hunting may cause their
extinction. At the same time, the relationship between
hunting and the human system is particularly important with
respect to socioeconomic development: hunting provides
subsistence and economic resources to local populations.
Hunting therefore connects the two systems and reveals their
interdependencies. In order to sustain both systems,
biodiversity conservation and socioeconomic development must
be integrated, for example through the sustainable
exploitation of wildlife, and sustainable development for
the human population.
The concept "biodiversity conservation" has many
meanings. Biodiversity refers to biological variability and
abundance at several scales: genes, species, communities or
ecosystems (McNeely, 1988; Reid and Miller, 1989; WRI et
al., 1992). Biodiversity conservation may therefore seek to
preserve particular ecosystem components (genes, species,
populations) as well as the patterns and processes that
complete ecosystems represent (Ehrlich and Wilson, 1991;
Noss, 1990; Reid and Miller, 1989).
In its strictest sense, conservation seeks to preserve
natural ecosystems free of human intervention, manipulation,
or management. Thus protected areas prohibit traditional
development activities such as agriculture, resource
extraction, and human settlement. Strict preservationists
emphasize the moral and aesthetic values of protecting
nature for its own sake, and the ecological services that
protected areas provide to society (Callicott, 1990; Lund,
1980; Nash, 1967).
However, conservationists began seeking economic
justifications for conservation efforts for two reasons.
First, conservation imposes economic costs on local people
in the form of land and resource alienation, together with
crop destruction and threats to personal safety from
wildlife (McNeely and Miller, 1984). Second, conservation
imposes economic costs on the nation in the form of
management expenses and lost opportunities to use the land
in more economically productive ways. At the local and
national levels, conservation competes with other forms of
land use, and the alternatives are usually evaluated on the
basis of short-term economic costs and benefits (Dixon and
Sherman, 1990; O'Riordan, 1988; Pullan, 1983b; Western,
1984a; 1984b). The economic incentives to exploit protected
area resources are strong, while protected area managers
lack the resources and the political commitment to prevent
destructive human activities.
The extreme "use it or lose it" view argues that unless
wildlife is economically valuable, it will be replaced by
more productive land use systems (Freese, 1994; Kock, 1995;
Luxmoore, 1989). Many conservationists are therefore
seeking viable methods for the sustainable use of wildlife,
methods that derive economic benefits without exterminating
species or degrading ecosystems.
"Development", like "conservation" is a term with many
meanings. Development implies the improvement or
fulfillment of potential (Daly, 1990b). Development can
have political or ethical implications, in terms of
achieving self-sufficiency and self-determination (Dasmann,
1984). But it is most often associated with improving
economic conditions according to criteria such as income,
efficiency, and productivity (Berger, 1992; Bodley, 1988;
Foresta, 1991). Thus the primary objective for many
development efforts has been to promote economic growth by
increasing the productivity of traditional economic and
subsistence activities, or by introducing new activities
(Burbridge, 1987). Development is achieved primarily
through technological and institutional innovation in food
production, resource extraction, industrial production, and
other economic sectors (Barbier, 1987).
Traditional development efforts therefore focus on
transforming natural ecosystems into more productive
artificial ecosystems managed by humans. In the case of
tropical forests the process has been extraction of
available resources through logging and mining, and
conversion to more productive land uses such as agriculture
or ranching. But these approaches have been severely
criticized from three perspectives:
1) Some bemoan economic growth without development for
the rural poor (Berger, 1992; Chambers, 1983; Independent
Commission, 1980; Lakshmanan, 1982; O'Riordan, 1989;
Redclift, 1984; 1987; Schumacher, 1973).
2) Others argue that generating short-term economic
benefits imposes severe long-term economic costs by
degrading the environment: tropical forests are
particularly fragile ecosystems (Denevan, 1989; Eden, 1978;
Nicholaides et al., 1985; N. Smith, 1976a; 1981).
3) Finally, proponents of "limits to growth" theories
argue that natural resources are limited, and the
environment's carrying capacity will soon be reached, given
current consumption patterns and population growth
(Brookfield, 1988; Daly, 1990a; 1990b; Fearnside, 1986;
"Sustainable development" was widely promoted in the
1980s as a means of addressing problems of poverty,
environmental degradation, and skewed resource distributions
that economic growth models have ignored (Barbier, 1987;
Fearnside, 1983; Lele, 1991; O'Riordan, 1989; Redclift,
1991; WCED, 1987). Most definitions of sustainable
development emphasize the maintenance of ecological and
economic viability through time. Development is
economically viable if economic benefits equal or exceed
economic costs. Development is ecologically viable if it
does not deplete biophysical resources or degrade ecosystems
(Brookfield, 1990; Goldman, 1995; Tisdell, 1988; Wilbanks,
Sustainable development promotes small-scale production
systems and appropriate technologies that minimize
environmental and sociocultural impacts (Browder, 1989;
Schumacher, 1973; Trainer, 1990). Geographers and
anthropologists in particular stress the importance of
adapting development activities to local economic, social,
and ecological conditions (Clay, 1988; Mabogunje, 1980;
Redclift, 1987; Richards, 1985; Watts, 1987; 1989). New
approaches to development therefore focus on the sustainable
use of natural resources and ecosystems, recognizing that
the conservation and management of natural resources is
essential to successful long-term socioeconomic development.
Integration of Conservation and Development
In turning to the sustainable exploitation of wildlife
and sustainable development respectively, development and
conservation practitioners have increasingly recognized the
mutual interdependence of their objectives (Lele, 1991).
Development depends on careful management of natural
resources, while conservation is not possible unless
development reduces pressure on natural resources.
Development can provide additional resources for
environmental protection, but environmental degradation
undermines development goals (McNeely, 1988; Whitaker, 1986;
World Bank, 1992).
Some researchers even argue that human cultural
diversity is a component of biodiversity, and that humans
are an integral part of nature (Bennett, 1975; Callicott,
1990). In particular, indigenous peoples are described as
"ecosystem people" who live within the ecosystem in a
sustainable manner (COICA, 1989; Colchester, 1992;
International Alliance, 1992; Klee, 1980; O'Connor, 1994;
Oldfield and Alcorn, 1991). Humans have helped to create
and maintain most tropical forest ecosystems; therefore to
exclude humans in the name of conservation will
fundamentally alter ecosystem processes and biodiversity
(Bahuchet, 1993; Bailey et al., 1990; Balee, 1989; Kormody,
1974; McNeely et al., 1990). Restricting people's access to
land and natural resources upon which they have historically
depended can also be disastrous for human societies.
Thus policymakers began to emphasize the role of parks
in regional and national development (MacKinnon et al.,
1986; McNeely and Miller, 1984; Pullan, 1983a), and the
potential for integrating production systems with the
environment (Brookfield, 1988). Wildlife, because of its
economic value, becomes a development resource (Abel and
Blaikie, 1986; CAR, 1992; Dalal-Clayton, 1988; Pullan,
1983b). But it will only remain a resource so long as
exploitation is not excessive.
In 1980, three of the world's largest conservation
agencies1 produced the World Conservation Strategy (WCS),
which defines three objectives for conservation: to
maintain essential ecological processes and life-support
systems; to maintain genetic diversity; and to ensure the
sustainable utilization of species and ecosystems which
support rural communities and major industries (IUCN, 1980).
The WCS recognizes that a major threat to conservation is
underdevelopment, and argues that conservation projects must
provide for economic growth to improve the economic status
and the quality of life for rural people (Erskine, 1985;
Halle, 1985). It also encourages development projects to
invent and apply methods that are ecologically sound, and
that conserve the living resources essential for human
survival and well-being (Allen, 1980; Talbot, 1984).
Efforts to integrate conservation and development have
adopted a variety of theoretical and practical models.
Conservationists have begun to promote the integration of
conservation efforts with development activities that
benefit local people and the national economy (Eltringham,
1984; Freese, 1986; Kundaeli, 1984). At the local level,
conservation projects recognize the legitimate rights of
rural people to utilize local natural resources (West and
Brechin, 1990). Furthermore, conservationists increasingly
1The International Union for the Conservation of Nature
(IUCN), in cooperation with the United Nations Environmental
Programme (UNEP) and the World Wide Fund for Nature (WWF).
seek the cooperation and support of local communities, as
well as their active participation in conservation
management (Barrow et al., 1993a; 1993b; Brown and Singer,
1990; Clay, 1985; Gibson and Marks, 1995; Kiss, 1990;
Western and Henry, 1979; Western and Wright, 1994). At the
national level, conservation projects promote the
sustainable exploitation of natural resources, through non-
consumptive (Caro, 1986; Lusigi, 1981; 1988; McIvor, 1989;
World Bank, 1990) as well as consumptive forms of wildlife
exploitation (Abel and Blaikie, 1986; Berry, 1986; Dalal-
Clayton, 1988; Lewis et al., 1990; Luxmoore, 1985; Metcalfe,
Integrated conservation and development projects
(ICDPs) combine core protection areas for tourism and
research with buffer zones or multiple use areas for
sustainable subsistence and economic activities (Wells et
al., 1992). The projects promote socioeconomic development
by providing health and education services, as well as by
introducing new economic opportunities and activities in
order to reduce local dependence on wildlife resources. At
the same time they promote biodiversity conservation by
protecting parks and restricting traditional economic
activities to ecologically sustainable levels and methods
(Brown and Singer, 1990; Du Toit, 1985; Ruitenbeek, 1992;
Sayer, 1987; Sharma, 1990; Western, 1984b; Zube and Busch,
In part ICDPs are a concession by international
conservation groups that police measures alone are not
sufficient to protect wildlife: in the long run local
poverty and population growth will overwhelm park
authorities' resources and commitment to conservation. At
the same time, ICDPs represent the hope that sustainable
exploitation of natural resources by local people is
possible, i.e., that careful management can generate short-
term benefits and long-term economic growth without
depleting the resource base. A proliferation of
publications argue that conservation and development are
compatible (BSP, 1993; Clad, 1984; Cleaver and Schreiber,
1994; IUCN, 1980; IUCN et al., 1991; Ledec and Goodland,
1988; McNeely and Miller, 1984; Oldfield and Alcorn, 1991;
WCED, 1987). However, evidence of success in the field is
scarce, and arguments to the contrary are numerous (Browder,
1990; 1992; Mares and Ojeda, 1984; Mordi, 1991; Redford,
1992; Redford and Sanderson, 1992; Robinson and Redford,
1994b; Struhsaker, 1990).
A comparative assessment of ICDPs across the tropics
finds that few provide viable alternatives to extensive
resource utilization practices, and they have difficulty
producing and distributing benefits from conservation. The
emphasis on local participation can lead ICDPs to respond
increasingly to short-term needs at the expense of long-term
issues. Although ICDPs encourage local participation and
empowerment, local people's needs and interests may include
"unacceptable" activities that overexploit or degrade the
environment (Brandon and Wells, 1992; Wells and Brandon,
Some critics argue that rural development components
are primarily a means to reduce tensions between parks and
local people, but do not attempt to provide sustainable
livelihood alternatives (Ghimere, 1991; Jeanrenaud, 1992).
According to others, ICDPs too often emphasize the promotion
of income generating activities and the provision of social
services, while neglecting resource management objectives
(Durbin and Ralambo, 1994). These problems can be addressed
in the implementation of specific projects.
However, more serious criticisms of ICDPs suggest
fundamental contradictions between conservation and
development objectives. Some development activities
directly undermine conservation objectives: roads improve
access for illegal woodcutters (Stocking and Perkin, 1992).
In addition, agricultural extension can make rural areas
more appealing, and may draw additional people near
protected areas, thus increasing the pressure on wildlife
resources (Oates, 1995; Southgate and Clark, 1993).
Immigration, wealth accumulation and population growth limit
the positive effects of development for local populations,
while even limited exploitation of wildlife resources
produces biotic impoverishment (Kremen et al., 1994).
Furthermore, in the long term the sustainable exploitation
of wildlife cannot support continuously rising human
populations and needs with a wildlife resource base that
fluctuates with environmental conditions and whose habitat
is declining (Barrett and Arcese, 1995).
The ICDP model assumes that by providing economic
benefits and alternative economic activities, local people
will alter their behavior with respect to wildlife.
Evidence suggests that this assumption is erroneous. Many
rural households have surplus labor and low opportunity
costs for their time. Therefore they can adopt new
activities promoted by the ICDP without abandoning those
activities that the ICDP seeks to eliminate, such as
poaching (Barrett and Arcese, 1995; Southgate and Clark,
1993). For most individuals, the benefits they receive from
the ICDP are less than the costs they incur. In addition,
ICDPs generally provide public services to communities as a
whole, and cannot exclude particular individuals who
continue to poach wildlife (Gibson and Marks, 1995).
Finally, the link between indigenous peoples and
biodiversity conservation is severely strained under market
pressures. Indigenous peoples have the same capacities,
needs, and desires to overexploit the environment as do
other peoples. Given more efficient technologies, growing
populations, and external markets for forest products,
resource exploitation by indigenous peoples no longer is
compatible with biodiversity conservation (Browder, 1992;
Gray, 1990; Marks, 1989; Plotkin and Famolare, 1992;
Redford, 1991; Redford and Sanderson, 1992; Robinson and
Redford, 1994b). These peoples have numerous economic
incentives to "mine" natural resources (Barbier et al.,
1994; R. Smith, 1981; Southgate and Clark, 1993).
Furthermore, development based on forest product
extraction,2 if it is successful in creating markets and
raising prices, inevitably fosters overexploitation as
external political and economic forces intercede (Dove,
1993a; Hanson, 1992; Jeanrenaud, 1992; Ryan, 1991). Others
argue that, because of political and social forces for
wealth accumulation, and the lack of understanding of
complex natural systems, resources are inevitably
overexploited, and sustainable use is impossible (Ludwig et
al., 1993). Thus wildlife is in a Catch-22 position: if it
has no economic value, alternative land uses will eliminate
wildlife habitat; yet if wildlife is valuable,
overexploitation is inevitable (Prescott-Allen, 1982).
In general, ICDPs require serious local and national
political commitment, conducive legislation, appropriate
institutions, low or stable population densities, widespread
use of traditional or appropriate technologies for resource
extraction, and effective protected area management--a set
of conditions unlikely to be found anywhere (Wells et al.,
2For example, extractive reserves in the Amazon.
1992). Notwithstanding these critiques, numerous efforts to
integrate development and conservation are underway across
the tropics, because of the local, national, and
international support for both biodiversity conservation and
socioeconomic development in tropical forests.
Conservation. Development and Wildlife:
The Role of Hunting
Hunting is an important subsistence and economic
activity for forest residents throughout the tropics. Most
forest inhabitants pursue a mixed subsistence and economic
strategy that combines hunting with cultivation, commercial
extraction of forest products, wage labor, etc.
Traditional3 hunting technologies are often very
closely adapted to particular ecological conditions: the
desired prey species, the availability of materials for
making weapons, the forest structure, the season, and even
the time of day (Bahuchet, 1988). Hunting methods also
depend on the particular historical and cultural context:
peoples in similar environments adopt different technologies
because of their contacts with other groups (Bahuchet,
1978). Finally, the economic and social environment
determines which technologies among those available are
3Many hunting methods that date back to pre-European
contact or pre-westernization times are still used today.
selected or commonly used: accessibility of technology,
skill and knowledge, human settlement or hunting group size,
subsistence versus commercial objectives, as well as
personal preference and prestige.4 As these cultural and
environmental conditions evolve over time, the role of
hunting in turn continually changes.
Some animals, such as tortoises, are captured by hand.
Clubs are used for killing creatures that could be captured
by hand, that are trapped in nets, or that are cornered by
dogs. Groups of hunters with spears, sometimes working with
dogs, hunt large game including elephants (Bahuchet, 1988;
Brosius, 1991; Harako, 1976; Sandbukt, 1988; Terashima,
1983; Vallois and Marquer, 1976).
Snares are widely used, and are extremely variable both
in terms of the prey captured and the particular techniques
employed. Pit traps, with or without sharpened and poisoned
stakes in the bottom, are used to capture large terrestrial
animals such as pigs and okapi. Gravity traps employ a
spear or log that falls when an animal triggers the trap.
4An important debate in the literature on Zaire Pygmies
discusses the reasons for the reliance on nets versus bows
and arrows by neighboring groups in the Ituri forest. Both
ecological and socio-economic explanations are proposed.
Ecological explanations focus on the structure of the forest
(Roscoe, 1990), the availability of plants used for making
nets (Bahuchet, 1989; Harako, 1976), or the density of
wildlife populations (Milton, 1985; Terashima, 1983).
Socio-economic explanations emphasize the importance of
commercial meat hunting and the value of women's labor
(Bailey and Aunger, 1989; Hayden, 1981; Wilkie and Curran,
1991), or population densities and relations with
neighboring farmers (Abruzzi, 1979; 1980).
Noose snares can be used for virtually any bird or animal,
and are placed on terrestrial or arboreal animal trails.
Alternatively, baits can be used to attract the prey. Nylon
and cable wire are widely used because they are stronger and
last longer than cord made of natural fibers (Schultz,
1986). Snares are often set around crops, both to protect
farms from wildlife depredations and to acquire meat from
animals attracted by the crops (Bahuchet and de Garine,
1990; Carpaneto and Germi, 1992; Orejuela, 1992). But
snares are also set out in the forest, from 20 to as many as
500 in a snare line that is regularly checked (Almquist,
1992; Hewlett, 1977; Infield, 1988; Wilson and Wilson,
1991a). In some cases hunters build long fences with gaps
in them, and place noose or gravity snares in the gaps
(Dwyer, 1990; Sandbukt, 1988).
A variety of projectile weapons are used for killing
terrestrial and arboreal animals of all sizes at a distance:
the bow and arrow, the crossbow, and the blowgun. Hunters
often apply poison to the arrows or darts. A single hunter
may search for game tracks and sounds, or hide in a blind
near a fruiting tree or an animal trail. Hunters also call
animals to bring them within range (Demesse, 1980; Harako,
1976; Harner, 1972; Stearman, 1989a). In Latin America
groups of hunters hunt together when a herd of white-lipped
peccaries has been sighted. The Efe and the Boyela in Zaire
conduct group bow hunts: a group of hunters forms a large
semi-circle, and a group of beaters drives game toward the
hunters (Sato, 1983; Terashima, 1983).
Finally, nets are a specialized hunting technology used
in African savannas and forests (Almquist, 1992; Arom and
Thomas, 1974; Berry et al., 1986; Demesse, 1980; Koch, 1968;
Newman, 1970; Sato, 1983; Sevy, 1972; Tanno, 1981;
Terashima, 1980), and also in India to hunt monkeys (Sinha,
1972; Williams, 1969). The Aka and Mbuti probably adopted
nets from neighboring farming peoples, but few
agriculturalists use nets today. Mbuti hunting nets measure
approximately 1.2 meters high and from 30 to 100 meters
long. They are normally used by a group of men and women
hunting together: several nets are joined together to form
a large semi-circle or a closed circle, and beaters drive
animals into the nets (Ichikawa, 1983). This is an
efficient technology for capturing small terrestrial mammals
weighing less than 20 kilograms, but larger animals are
usually able to break through or leap over the nets.
Hunting methods depend not only on ecological factors,
but also on the role of other economic and subsistence
activities. Farmers tend to hunt near their residences,
venturing out for day hunts or longer stays during periods
when less agricultural labor is required. More mobile
hunter-gatherers, like the Aka of CAR, the Mbuti of Zaire,
the Agta of the Philippines, or the Ache of Paraguay, often
hunt for extended periods from forest camps that can be
several days' walk from roads or permanent settlements.
Across the tropics, modernization means that
traditional cross-cultural diversity in hunting methods is
giving way to the shotgun as an all-purpose, all-season
hunting weapon. The shotgun has a greater range than
traditional weapons, it is often more accurate, and heavy
shot is not deflected by intervening vegetation between the
hunter and the target (Hames, 1979; Rambo, 1978).
The shotgun does have limitations, including the high
cost of guns and ammunition (Beckerman, 1980; Chin, 1984;
Laurent, 1992; Nietschmann, 1972; Paolisso and Sackett,
1985; Saffirio and Scaglion, 1982), reliability problems
with wet powder and misfiring (Yost and Kelley, 1983), and
the noise of firing which scares away other game (Alvard,
1993; Baksh, 1984; Rai, 1982; Ross, 1978). There are also
legal restrictions on owning guns: many countries require
firearm licenses; and Malaysia, Indonesia and the
Philippines have totally banned shotguns under martial law
(Endicott, 1979a; Griffin, 1981; Hoffman, 1986; Morren,
Pressure on Wildlife Resources
Indigenous forest hunter-gatherers adapted to their
environment by living in small, mobile, and dispersed
groups. As they depleted wildlife resources in one area,
they split into smaller groups or moved their camp elsewhere
(Baksh, 1985; Vickers, 1980). Forest farmers also generally
lived in small dispersed settlements. The pressure on
wildlife was geographically and temporally extensive, with
fallows in space and time allowing wildlife populations to
recover and maintain themselves despite human exploitation.
These fallows resulted from a variety of cultural practices:
hunting zone rotation (Almquist, 1992; Balee, 1989; Hames,
1980; 1986; Morren, 1986; Sponsel, 1980), buffer zones
between antagonistic groups (De Boer, 1981; Gross, 1975;
Sellato, 1994), hunting sanctuaries (Turnbull, 1983),
seasonal trekking (Moran, 1981b), and seasonal hunting
(Bahuchet, 1985b; Dwyer, 1982; Eder, 1988a). Traditional
forest hunting was probably sustainable because of low human
population density, simple technology, and subsistence-
oriented production (Redford, 1991; Schmink et al., 1992;
Uquillas, 1985; Vickers, 1991).5
These conditions rarely exist in tropical forests
today. Wildlife exploitation is becoming more intensive, as
both temporal and spatial fallows are decreasing: more
people are hunting continuously in smaller and smaller
areas. The human population in forest regions is growing,
with larger and more permanent population centers (Bahuchet,
5However, even subsistence-level production with simple
technologies may severely depress populations of certain
species, for example slowly-reproducing primates (Godoy and
Bawa, 1993; Peres, 1990; Redford and Robinson, 1985).
1985a; Bahuchet and Guillaume, 1979). A larger number of
people, including immigrants and urban dwellers, now depend
on the same wildlife resource base. Hunting is increasingly
market-oriented (Seeger, 1982).
Large-scale government colonization plans in Brazil and
Indonesia have encouraged landless people in high-density
areas to migrate to relatively unpopulated forests. But in
other countries similar population shifts are occurring
without formal government incentives (Hart and Hart, 1984;
Peterson, 1992a; 1992b; Wilkie, 1987a). Forests comprise an
important frontier that was not exploited more intensively
when there were easier and less marginal environments to
exploit. Other lands are often no longer available for poor
people who must farm to feed themselves. In addition,
valuable products exist in forests: timber, minerals such
as gold and diamonds, and animal products such as ivory,
skins, and bushmeat.6 Technologies and capital are now
available to exploit all these resources intensively.
Hunting is an important subsistence and economic
adaptation that allows forest peoples to survive. But the
available hunting area is declining as people migrate to
forest regions, and as exploitative activities convert
forest to other uses such as cattle ranches, farms,
plantations; or simply degrade wildlife habitat by
6"Bushmeat" is a term from west Africa that refers to
all meat from wild animals killed for food.
intensively extracting resources, for example through
logging and mining (Griffin, 1985; 1989; Headland, 1986;
Rodgers et al., 1991; Stearman, 1990). Furthermore, the
international movement to preserve tropical forests is
providing external funds for tropical countries to create
protected areas in forests, areas which often prohibit or
constrain hunting activities (Doungoub6, 1990; Nations and
Hinojosa, 1989). At the same time, shifts to new
technologies such as firearms and cable snares, combined
with production for external markets as well as subsistence
needs, all tend to increase the intensity and efficiency of
hunting activities. Although few researchers have collected
both socioeconomic and ecological data,' it is likely that
harvest rates are exceeding reproduction rates for many
Wildlife Management Practices
Forest peoples in most cases exhibit a fatalistic
attitude towards wildlife, exploiting wildlife resources as
if they are unlimited. Some hunters associate hunting
yields with mystical spirits: if yields decline it is
because the spirits have not been properly treated, not
because people have overhunted (Bulmer, 1982; Dwyer, 1982).
7The exception is a research team in Peru which has
collected abundance, productivity, and harvest rates for
particular game species in a particular location (Bodmer,
1994; Bodmer et al., 1988a; 1988b; 1994; 1995).
Much indigenous knowledge of wildlife, intimate though it
may be, focuses on harvesting as opposed to managing these
resources. Therefore, most forest peoples do little to
conserve harvests. The primary concern is for short-term
yields, not for long-term conservation of wildlife (Bulmer,
1982). Hunting is usually opportunistic: any animal of any
species encountered is pursued, and hunters do not
discriminate by sex or age of prey, capturing females and
young whenever they are available (Alvard, 1993; 1994; Hames
and Vickers, 1982; Redford and Robinson, 1985).
In the past, there were always other unoccupied areas
to which people could move when local resources were
depleted, and permanent environmental degradation did not
result from their activities (Johnson, 1989; Kaplan and
Kopische, 1992). In the modern context, perhaps they lack
economic alternatives and must emphasize short-term needs at
the expense of long-term sustainable resource management.
Alternatively, they may fail to anticipate future scarcity
resulting from overexploitation because resources have
always been abundant in the past.
Taboos and other cultural beliefs may serve to manage
or protect wildlife by reducing the motivation to hunt
particular species (Silberbauer, 1981; Smith, 1976b;
Sponsel, 1980), and by distributing hunting pressure across
a greater diversity of species (Arhem, 1976). However,
traditional belief systems are increasingly superseded by
western culture (Bennett, 1962; Dwyer, 1982; Hames, 1991).
Market pressures undermine taboos to the extent that the
market places a premium on previously unexploited species,
encouraging individuals to violate cultural norms for
material gain (Berlin and Berlin, 1983; Moran, 1981a). As
other game declines, pressure increases to hunt tabooed
species (Nietschmann, 1973; Peres, 1990). In some cases,
although people will not consume certain species of game,
they will kill that species when encountered because the
meat can always be sold (Johnson, 1989; Sponsel, 1980). In
other cases, previously "inedible" or tabooed species are
being reclassified as edible (Hames and Vickers, 1982; Speth
and Scott, 1989; Yost and Kelley, 1983).
When there are few visible signs of degradation, there
are also few incentives to conserve wildlife resources, and
formal institutions or controls on hunting activities do not
develop (Harms, 1987; Mulongo, 1989; Testart, 1977). Mobile
populations not tied to a specific resource base and defined
territory gain little from prudent resource use (Gadgil et
al., 1993). Alternatively, people may not perceive
declining wildlife as a risk at all, or as a risk that they
are able to address (Kottak and Costa, 1993). Often they
are unable to restrict access to hunting areas and wildlife
(Bahuchet, 1979b; Hames, 1986; Orejuela, 1992; Rodgers et
al., 1991). Rather than a "tragedy of the commons" there is
a tragedy of open access resources (Feeny et al., 1990;
Hardin, 1968; McCay and Acheson, 1987). Professional
hunters from elsewhere have little difficulty in entering
the area to pursue their short-term economic goals, while
other immigrants can also freely establish residences and
farms. Local people then lack the incentives to conserve
wildlife resources because they bear all the costs and are
able to capture few of the benefits in return.
The Subsistence Role of Hunting
The subsistence role of hunting for human populations
depends on the other subsistence activities possible in the
physical and cultural environment. Across the tropics,
wildlife meat or "bushmeat" is an important subsistence
resource for forest peoples. In west and central Africa,
60-80 percent of meat consumed by forest residents is
bushmeat (Ajayi, 1979; Asibey, 1974; 1987; Heymans and
Meurice, 1973; Martin, 1983; Prescott-Allen and Prescott-
The role of wildlife meat in the diet varies
considerably over time, and among neighboring ethnic groups
and settlements. People who do not farm depend more on
wildlife for subsistence, both directly consuming the game
they capture, and indirectly to the extent that they sell
meat in exchange for other foods. Central African Pygmies
traditionally maintained trading relationships with farmers
of other ethnic groups (Bahuchet and Guillaume, 1979; 1982;
Bahuchet and Thomas, 1986; Berry et al., 1986; Delobeau,
1989; Terashima, 1986). Similar long-standing symbiotic
trading relationships occur in Brazil (Milton, 1984), and
across Asia (Gardner, 1969; Griffin, 1981; 1984; Hoffman,
1988; J. Peterson, 1978a; 1981; Rai, 1982; Rambo, 1979a;
1980; 1982b). Although meat is traded, production is for
subsistence at the local level: hunters provide the
subsistence requirements of meat for both groups, while
farmers provide the subsistence requirements of starch.
Cultivation methods and crops can affect hunting
intensity and frequency. Certain crops like manioc require
relatively little attention. Manioc farmers can therefore
spend extended periods away from their fields hunting in the
forest (Nietschmann, 1973). By dispersing fields throughout
the forest, forest peoples can effectively expand their
hunting range (Hart, 1979; Posey, 1985). On the other hand,
crops that require much more care, for example rice or
maize, reduce the time available for hunting, and often
increase the reliance on trapping (Behrens, 1984; Carpaneto
and Germi, 1992; Dwyer, 1985; Dwyer and Minnegal, 1991;
Sandbukt, 1988; Sato, 1983). Thus, increasing dependence on
agriculture may reduce the subsistence role of wildlife
(Bahuchet, 1985b; Johnson, 1977). But by providing greater
food security, which allows population density and
settlement size to increase, cultivation may increase
hunting pressure, particularly on large game species which
provide the highest returns (Speth and Scott, 1989; Werner
et al., 1979).
Some researchers argue that cultivation can increase
the abundance of game species, and therefore the potential
subsistence role of hunting. Traditional shifting
cultivation creates a mosaic of forest patches at different
stages of regrowth' (Bailey et al., 1990; Barnes et al.,
1991; Hart and Petrides, 1987; Ross, 1978; Sato, 1983;
Wilkie, 1987b; Wilkie and Finn, 1990), increases the
abundance of forest/forest edge ecotones (J. Peterson, 1977;
1981; 1982), and provides food sources for wildlife in both
current and abandoned farms (Linares, 1976; Posey, 1982;
1985). The vegetation diversity benefits many opportunistic
or colonizing wildlife species, or those which depend on two
or more habitat types, including important game species like
pigs and deer in Asia, and rodents in Africa and Latin
America (Dufour, 1990; Speth and Scott, 1989).
The Economic Role of Hunting
The boundary between subsistence and commercial
production is often indistinct: all meat that is not
consumed can be sold in local markets (Peres, 1990). For
many forest peoples, hunting has for generations or even
centuries had economic as well as subsistence objectives
(Bower, 1989; Healey, 1990; Rambo, 1979b; Sellato, 1994;
8Selective logging can perform a similar function.
Spielmann and Eder, 1994). For the past 50 years,
commercial hunting of crocodiles for skins has helped the
Sirion6 of Bolivia through annual periods of agricultural
scarcity, and allows them to obtain luxury goods (Stearman
and Redford, 1992). In fact, hunting is an integral part of
all forest-based activities, a "subsidy from nature" without
which other commercial activities like rubber tapping or
Brazil nut collecting would not be possible (Hecht et al.,
1988; Redford, 1992; 1993). Likewise, hunters supply meat
to gold miners and loggers (Alvard, 1995; Stoll, 1992).
As urban populations increase, rural populations become
ever more important as food producers. Urban areas,
especially in Africa, exert a particularly strong pressure
on hunters in forest areas to produce bushmeat (Anadu et
al., 1988; Colyn et al., 1987; Falconer, 1990; Steel, 1994).
This market provides a major income-earning opportunity for
forest peoples who have in many cases benefitted little from
development elsewhere in the country (Infield, 1988).
Furthermore, professional hunters are increasingly turning
their attention to forest areas as wildlife resources are
depleted in more accessible regions (Rodgers et al., 1991).
Urban dwellers in Ghana make weekend hunting trips to forest
areas to earn supplementary income (Asibey, 1980).
The bushmeat trade increases the intensity of hunting
by expanding the population base consuming the meat, and the
time spent hunting (Colyn et al., 1987; Hart, 1978).
Commercial meat traders, by provisioning hunters with food
and hunting equipment, can also promote the expansion of
hunting into more remote areas that were previously
inaccessible. Thus the distribution of Mbuti hunters in
Zaire no longer depends on the distribution of farming
villages to supply their carbohydrate needs (Hart, 1979;
Peacock, 1984). Trade also alters hunting methods by
diffusing new technologies9 from outside forest areas, and
by causing hunters to focus on more marketable prey species
The long-term indirect effects of trade on hunting and
social change are difficult to predict (Godoy and Bawa,
1993). Trade may induce specialization by particular groups
in hunting: trade allows neighboring ethnic groups to
coexist by emphasizing narrower ecological niches, thus
increasing the potential human carrying capacity of the
environment and reducing the potential for conflict
(Bahuchet et al., 1990; Berry et al., 1986; Fox, 1969;
Headland, 1986; Milton, 1984; Peterson, 1978b; Turnbull,
1965). In Asia, the trade in wildlife products has affected
hunting practices for centuries: inducing relatively
sedentary agriculturalists to become mobile hunter-gatherers
in order to more effectively harvest forest products for the
market (Hoffman, 1986). Trade has encouraged the Miskito of
'For example, nets and crossbows in central Africa, and
Panama to emphasize meat production at the expense of
subsistence agriculture, to the extent that hunting
activities conflict with cultivation for time, space and
labor (Nietschmann, 1972; 1973). Alternatively, certain
individuals within groups become professional hunters (Ayres
et al., 1991; Carpaneto and Germi, 1992). The persistence
of these specialist individuals or groups through time
clearly depends on the persistence of wildlife as an
economically important resource. Intensive exploitation may
deplete wildlife to the point where it can no longer support
specialized hunters. As they turn to alternative economic
and subsistence activities, hunting will decline.
Based most importantly on the work of Julian Steward,
cultural ecology combines theories and methodologies from
geography, anthropology, and ecology. Cultural ecology
attempts to grapple with the extremely complicated problem
of human-environment interactions through a systems approach
that integrates ecological and socioeconomic systems. It
has provided a general framework for analysis of
interactions, rather than specific methodologies of its own.
Research has emphasized people-environment relationships in
developing countries. In this way, cultural ecology can
play an important role in guiding current efforts to
integrate conservation and development, two subjects which
are particularly problematic in tropical forests. In recent
years, natural scientists promoting ecosystem conservation
and social scientists advocating human system "development"
have begun to recognize the interdependencies of their two
This dissertation seeks to build upon and advance the
theory and practice of cultural ecology described above.
The field work continues in the geography and cultural
ecology traditions to integrate disciplines and research
subjects. Rather than analyzing the entire
people/environment system, the dissertation focuses on
hunting in order to investigate ecosystem/biodiversity
conservation and human system/socioeconomic development, and
attempts to integrate the two in a particular African case
Wildlife exploitation for subsistence and commercial
purposes can contribute to socioeconomic development. If
exploitation is sustainable, it can also support
biodiversity conservation. But sustainable exploitation
depends on appropriate management practices and the ecology
of the resource base.
People are currently harvesting wildlife, and will
continue to do so, throughout tropical forests because wild
animals provide both protein and income. The complete
prohibition of hunting is unrealistic and unenforceable.
Integrated conservation and development projects seek to
direct this exploitation toward more sustainable practices
and levels. Such a course of action requires accurate
information on the ecosystem, in the form of biological and
ecological data on local game species, combined with
information on the human system, in particular on hunting
methods, motivations, and harvest rates.
This dissertation provides both types of information
for the Bayanga region of the Central African Republic based
on 16 months of fieldwork, and complemented by data from
research elsewhere. The following chapter describes the
ecosystem and the human system of the Bayanga region.
Chapters 4 and 5 report the results of the study of cable
snare hunting and communal net hunting respectively.
THE BAYANGA REGION
The cultural ecology framework emphasizes the relations
between two systems: the ecosystem and the human system.
The research site is the Bayanga region of the Central
African Republic, the area south of Nola that is bounded by
the Congo border to the east, the Cameroon border to the
west (Figure 3.1). This chapter examines the components of
each system in the Bayanga region.
The regional ecosystem, like other tropical
rainforests, contains high species diversity of plants and
animals. This chapter focuses on the resource base
represented by the primary game species and implications for
their sustainable harvesting. Components of the human
system include political authorities, economic activities,
and population centers. Change in each of these components
over time in turn affects patterns of wildlife exploitation.
In order to illustrate the influence of hunting on relations
between the ecosystem and the human system in the Bayanga
region, the chapter concludes by discussing several cases
and issues: elephants, hunting legislation, bushmeat
markets, and currency devaluation.
Figure 3.1: The Central African Republic and the Research
Source: Carroll, 1986b.
The tropical rainforest ecosystem of the Bayanga region
is complex, and offers many resources that have long been
exploited by colonial and independent governments, foreign
companies, immigrants, and local residents. This section
describes general ecosystem characteristics, then focuses on
wildlife resources, which are exploited by local residents
for food and for markets. The principal game species are
described in detail, with particular attention given to
population densities, predictions of sustainable harvest
rates, and the impacts of harvesting.
The Bayanga region lies at the upper limit of the great
Congo basin tropical rainforest. Relief is relatively flat,
averaging 350 meters in altitude to the east of the Sangha
river, with hills rising to 700 meters to the west of the
Sangha. The entire region is drained by the Sangha river,
flowing south to the Oubangui and the Zaire rivers.
Seasonal temperature variations are slight: monthly
averages vary only 20 Celsius. But diurnal variations are
as high as 140 C (Figure 3.2). Average annual rainfall of
less than 1,400 millimeters is low for a rainforest
(Richards, 1952). A three-month dry season lasts from
December to February, though it does rain during this period
(Figure 3.3). Because of these relatively constant and
stable climatic conditions, most animals are permanent
residents that do not make long-distance seasonal
migrations, and reproduction continues throughout the year.
Maximum, minimum, and monthly averages
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 3.2: Average Temperatures (OC): Bayanga, 1974-1984
Source: Carroll, 1986b.
Average annual rainfall I
May Jun Jul Aug Sep Oct Nov Dec
Figure 3.3: Average Rainfall (mm): Bayanga, 1973-1984
Source: Carroll, 1986b.
Forest types include evergreen, deciduous and
evergreen-deciduous transition forests. Closed forest
formations cover 94 percent of the 8,330 km2 area from Nola
south, including mixed forests and patches of
Gilbertiodendron dewevrei monodominant stands on well-
drained soils (Figure 3.4). Poorly-drained soils are
covered with almost pure stands of Guibourtia demeusii,
Gilbertiodendron dewevrei, or raffia palms (Raphia sp.).
SMarshy clearing (bi)
Mixed dosed forest
Gilbertiodendro dewevrel forest
Figure 3.4: Vegetation of the Bayanga Region
Source: Carroll, 1986b.
0 10 25
Patches of savanna occur to the northeast. Herbaceous
marshy forest clearings called "bai" are maintained, and
perhaps created, by heavy wildlife usage, particularly
elephants searching for minerals in the soil (Carroll,
Wildlife diversity, as in other tropical forests, is
high (see Appendix 1 for a species list). Wildlife
exploitation focuses primarily on mammals, although many
species of birds, reptiles, and insects are also collected.
The most important mammal species from a conversation
perspective are the forest elephant (Loxodonta africana
cyclotis) and the lowland gorilla (Gorilla gorilla gorilla)
which have been surveyed locally by Carroll (1986c; 1988)
and Fay (1989; 1991).1
In addition, a variety of ungulate species are present:
forest buffalo (Syncerus caffer nanus), bongo and sitatunga
antelope (Tragelaphus euryceros and T. spekei), seven
species of duikers (Cephalophus spp.) and two types of pigs
(Potamochoerus porcus and Hylochoerus meinertzhageni) (Fay
et al., 1990; Wilson and Wilson, 1989). Fifteen species of
primates occur, including chimpanzee (Pan troglodytes) and
several species of monkeys (Cercopithecus spp., Cercocebus
spp., Colobus guereza, and Procolobus badius). The
carnivores include leopard (Panthera pardus), golden cat
1Additional research is in progress: on elephants by
Andrea Turkalo, and on gorillas by Melissa Remis and Michele
(Profelis aurata), and several mongoose and genet species
(Viverridae) (Blom, 1993; Carroll, 1986b; 1986c).2
Most forest mammals that are primary consumers are
frugivorous, though the larger species also browse. Grazing
is limited to the several dozen marshy clearings and is
probably only important to buffalo. However, many other
species also frequent bais to obtain minerals such as
calcium. The Dzanga bai, 300 meters by 150 meters, is most
noteworthy for the spectacle of elephant agglomerations
exceeding 100 individuals.3 In addition to the elephants,
present virtually 24 hours a day since anti-poaching efforts
took effect in 1988, other species seen at Dzanga include
buffalo, bongo, sitatunga, black-fronted duiker, bush pig,
giant forest hog, as well as flocks of African grey parrots.
Gorillas visit some of the other bais.
Wildlife abundance and dispersal is related to the
nature of food resources. The diversity of trees and the
relatively weak seasonality ensures that some species are
fruiting at all times of the year, but the food resources
are patchily distributed. In order to exploit these
resources, animals which forage in groups move around
extensive areas. These animals include the diurnal primates
2Justina Ray has studied mongooses in the Bayanga
3Unlike savanna elephants, the forest subspecies forms
only small groups of 2-4 individuals (Merz, 1986; White et
and the larger terrestrial mammals such as elephants,
buffalo, bongo, and bush pigs. The smaller terrestrial
mammals such as sitatunga and all duikers) are relatively
sedentary and solitary.
The four principal game species exploited by local
people, for subsistence and for the trade in bushmeat, are
the brush-tailed porcupine (Atherurus africanus) and three
duikers (Cephalophus callipygus, C. dorsalis, and C.
monticola). These species are described in detail below.
Appendix 2 provides biological information for the four
game species, based on measurements of captured animals in
the Bayanga region and on detailed studies by researchers
elsewhere in Africa. Information on duiker reproduction is
inconsistent, but the most accurate information is available
from Vivian Wilson's on-going breeding research at
Chipangali Wildlife Trust in Zimbabwe. Duikers bear only
one young at a time. They breed continuously throughout the
year, although birth rates are somewhat higher in particular
seasons of the year. Individuals of all species reach
sexual maturity (first oestrus) at 11 months, and after a
gestation period of 7 months produce their first offspring
at 18 months. Conception occurs again within days of
parturition. Therefore female duikers reproduce every 210
days, and are pregnant virtually continuously. Reproductive
rates in the wild may be somewhat lower, perhaps one young
per female per year. Longevity is probably 8-10 years.
Very little is known about A. africanus, but it is thought
to reach sexual maturity at two years of age, and to
reproduce one young at a time after a gestation period of
100-110 days (Rahm, 1962).
Individuals of all duiker species are generally
solitary, except for C. monticola which often forage in
pairs or even small groups including two parents and a young
animal (Dubost, 1980). A. africanus forages alone, but is
less territorial than the duikers, with several individuals
and families sharing a sleeping area (Emmons, 1983).
All species are principally frugivorous, though the
duikers browse as well, and A. africanus digs for roots and
tubers. In addition, duikers consume small amounts of
animal matter and insects in order to obtain necessary salts
(Kingdon, 1982). Duikers consume fruit in direct proportion
to fruit abundance: when fruit is not available, more
leaves are consumed (Feer, 1989a). In the rain forests of
Gabon and Zaire fruits comprise more than 70 percent of the
diet throughout the year (Table 3.1).4
4But in South African dry forests, where fruit is not a
reliable resource, C. monticola depends on leaves for 70
percent of its diet (Faurie and Perrin, 1993).
Table 3.1: Game Species Activity, Weight, and Diet
(diurnal/nocturnal, kgs. percent of fruit/leaves in diet)
Activ Weight Fruit Leaves Fruitc Fruitd
C. callipygus" D 20.1 82.7 16.3 86-89 88
C. dorsalisa N 21.7 72.9 26.6 86-89 75
C. monticolaa D 4.9 78.5 20.3 75
A. africanusb N 3.3
Activity: D=diurnal, N=nocturnal.
Weight: average for species, in kg.
Fruit: percent of fruit in diet (dry weight).
Leaves: percent of leaves in diet (dry weight).
Sources: From Gabon: aDubost, 1984; bEmmons, 1983; and
cFeer, 1989a. From Zaire: dHart, 1985.
Because ecological conditions in the Bayanga region are
relatively stable and predictable, ranges and diets likewise
do not vary much. Most duikers exhibit little weight change
in the dry season, when food resources are least abundant,
although the larger duikers expand their home ranges during
this season (Dubost, 1984). All four species are
territorial, and they probably remain on the same territory
throughout their lifetime. In South Africa, C. monticola
are so strongly territorial that they rarely leave their
home range even when beaters shouting and shaking leaves try
to drive them out: instead they double back through the
line of beaters or hide (Bowland, 1990). More detailed
information on the four game species is provided below.
A. africanus is strictly nocturnal, hiding by day in
thick brush or in burrows abandoned by other animals. It
may use the same shelters for many years, with well-defined
paths to established feeding areas. It forages alone, but
often joins others in dens during the day. Studies in Gabon
find home ranges averaging 13.3 hectares. However, it is
possible that members of a clan share a territory (Emmons,
1983; Kingdon, 1982; Rahm, 1962).
C. callipygus males maintain a home range of 27-49
hectares, while females' home ranges are 40-42 hectares.
Territories are larger in the dry season. Reproduction is
continuous throughout the year. C. callipygus prefers
primary forest with relatively thin undergrowth (Estes,
1991; Feer, 1989a; 1989b).
C. dorsalis is strictly nocturnal, and is much less
active than the diurnal C. callipygus, covering in its daily
foraging only one-fourth the distance that the latter covers
(Estes, 1991). It hides in tree hollows or very thick brush
by day, but at night forages in more open areas. Studies in
Gabon find male home ranges (79 hectares) overlapping two
female home ranges (41 hectares), and territories are larger
in the dry season (Dubost, 1983; Feer, 1989a; 1989b).
Research in Zaire reports territories averaging 15.2
hectares, but individuals also will make direct long-
distance moves to known food patches (Hart, 1985).5
5Reported differences in home range size may result
from different research methods, or from habitat
C. monticola occupies all types of forest where the
undergrowth is sufficiently clear (visibility greater than
20 meters), including primary and secondary forest resulting
from cultivation and logging (Fimbel, 1994). It forages in
these clear areas, but rests and hides from danger in denser
vegetation and brush (Estes, 1991; Hanekom and Wilson,
1991). It is exclusively diurnal, and is active for a
longer period in the dry season, perhaps because less food
Studies find male-female pairs sharing territories of
3.7-6.4 hectares in Zaire (Hart, 1985), and 2.5-4 hectares
in Gabon (Dubost, 1980). The home range varies little with
the seasons, remaining quite stable throughout the adult's
life. Each family member protects its territory from
outsiders of the same sex. Males may venture out of their
territories but only 100-300 meters to a particular fruiting
tree, and for a few hours at most. Male-female pairs forage
together or alone, but are sometimes accompanied by their
own or migrant young. The young migrate to find unoccupied
territories, and annual population turnover is from 7-10
percent (Dubost, 1980; 1983). Reproduction occurs
throughout the year, but is relatively more common in the
dry season (Mentis, 1972).
This section describes population characteristics of
the four game species, most importantly population
densities, age structure, and sex ratios. These
characteristics are critical in determining the effects of
hunting on game species, and especially in evaluating
whether hunting is sustainable.
Densities are the population characteristic most often
measured in the field (Table 3.2). Density estimates may
vary because of differences in methodologies: track and
pellet counts, line transect surveys, and radio-telemetry.
Variations among research sites also result because of
differences in ecological interactions such as vegetation
types or competition with other frugivores, as well as
differences in patterns of human intervention: hunting
pressure and habitat disturbance.
Table 3.2: Population Densities for Game Species
at Research Sites in Gabon, Zaire and Cameroon
(individuals per square kilometer)
(1) (2) (3) (4) (51) (6)
A. africanus 77.7 12.0a 45. ib 30.0
C. monticola 70 30.4-53.0 62-78c 14.9 61-69
C. callipygus 10.7-15.5 0.6-6.7 3.2
C. dorsalis 6.3-8.7 2.5-6.8 1.5
Sources: For Gabon: (1) Feer, 1988; 1989b; 1993; (2) Lahm,
1993; (3) bEmmons, 1983; and CDubost, 1980. For Zaire: (4)
Hart, 1985; (5) Wilkie, 1987b. For Cameroon: (6) Payne,
Methods: I have included duiker densities only for sites in
Gabon and Zaire, because the same guild of duiker species
occurs in these sites as in the Bayanga region.
Feer, Dubost, Emmons and Hart used radio-telemetry to
measure home ranges. This is the most accurate method of
determining population densities. bEmmons provides only
average home ranges for A. africanus, which I have used to
calculate densities assuming seven individuals per adult
Hart also conducted censuses using groups of net
hunters, as well as pellet and track count surveys. Wilkie
conducted track and pellet count surveys as well.
Lahm and Payne conducted day and night line transects.
"Lahm recorded only encounter rates for A. africanus, which
I have used to calculate approximate densities according to
Payne's (1992) mean sighting distance for the species in
night transect surveys.
Age structure and sex ratios
Emmons (1983) reports that males comprise 52 percent of
subadult A. africanus, and 58 percent of adults. The only
age structure and sex ratio information on duikers in the
literature is for C. monticola in Gabon (Table 3.3).
Table 3.3: Age Structure for C. Monticola
(number and percent female/male by age classes)
In region (results from hunting)
Embryos Births MO M1 M2 Subad Adults Repr
Number 20 10 11 8 29 22 54 76
Female (%) 30 50 62 75 59 69 44 51
Male (%) 70 50 38 25 41 31 56 49
In study area
Embryos Births MO M1 M2 Subad Adults Repr
Number -- -- 5 13 28 23 79 102
Female (%) -- -- 60 68 54 67 49 53
Male (%) -- -- 40 32 46 33 51 47
Notes: MO = 0-4 months old, no molars visible.
M1 = 4-10 months old, 1st molar erupting, but not 2nd.
M2 = 10-20 months old, 1st and 2nd molars out, but not 3rd.
Subad = sub-adults, 20-28 months, complete dentition.
Adult = older than 28 months, tooth wear visible.6
Repr = Total reproducing individuals including adults and
Source: Dubost (1980), p. 247. Reprinted with permission
of the publisher, Blackwell Wissenschafts-Verlag GmbH,
Dubost assumes that all individuals in the subadult and
adult age classes are breeding. However, young individuals
without territories probably cannot breed successfully, so
the actual breeding population may be smaller than the
number of sexually mature individuals. The age and sex
structure data for C. monticola exhibit a strong deficit of
young males in the population--these are the individuals
most constrained by intraspecific competition for unoccupied
territories (Dubost, 1980). Young are forced by their
'These age categories do not correspond to those of
Vivian Wilson, who finds captive duikers reaching sexual
maturity, and presumably having complete dentition, within
one year. However, most mammals grow more quickly and
reproduce at an earlier age in captivity than in the wild.
parents to emigrate and find unoccupied areas to claim for
themselves. Their survival therefore depends on being able
to find a suitable territory. Territoriality is determined
by the availability of food resources as well as competition
for enemy-free space. Mortality results from young being
forced into more unsafe environments, for example outside
protected areas or near human settlements.
The net effects of other species on the game species
are complex interactions of predation, competition, and
facilitation. Natural predators of duikers and porcupines
in the Bayanga region include leopards, golden cats, eagles,
pythons and large vipers. Other natural forms of mortality
include old age, disease, starvation, and accidents.7
Natural mortality removes territorial adults and creates
gaps for young individuals without territories to colonize.
Mortality rates from natural causes for young duikers less
than two years of age are high: 30 percent for C.
monticola, 70 percent for C. callipygus, and 87 percent for
C. dorsalis (Dubost, 1980; Feer, 1988).
The game species also compete with other frugivores,
for example, monkeys, squirrels, birds, and elephants
(Gautier-Hion et al., 1980). One study suggests that duiker
7During my fieldwork net hunters found a dead sitatunga
mired in mud, and a hippopotamus died near Bayanga in the
same way. Several years previously a dead elephant was
found trapped between a tree and a river bank.
densities are lower where abundant elephants compete with
duikers for fruit (White, 1994a). But game species derive
benefits from other animals at the same time: arboreal
frugivores pick fruits and drop them to the ground, so
duikers often follow and feed below mixed monkey troops
(Fay, 1989; Feer, 1989a). An estimated 50 percent or more
of fruit available to terrestrial ungulates consists of
fruit or parts of fruit discarded by primates (Hart, 1985).
Furthermore, elephants benefit duikers by clearing trails
through the forest, and by maintaining bai clearings where
minerals are available (Carroll, 1986a; 1986c).
Estimated Population Densities in the Bayanga Region
Researchers have employed a variety of techniques to
estimate population densities of terrestrial wildlife in
African forests: day and night line transects, pellet and
track counts, and radio-telemetry (Dubost, 1980; Emmons,
1983; Feer, 1989b; Fimbel, 1994; Hanekom and Wilson, 1991;
Hart, 1985; Heymans and LeJoly, 1981; Lahm, 1993; McCoy,
1995; Nummelin, 1990; Payne, 1992; Struhsaker, n.d.; White,
1994a; Wilkie, 1987b). Radio-telemetry is the most accurate
method, yet also the most expensive and time-consuming. All
other methods are problematic, especially for counting small
cryptic animals such as duikers in thick vegetation. Census
methods are therefore more reliable for determining indices
of abundance rather than absolute density estimates.
Line transect surveys
I chose to conduct day-time line transect surveys for
several reasons. Because a conveniently-located set of
transects already existed, this method was the easiest and
conflicted least with other research activities. In
addition, pellet and track counts are unable to distinguish
between C. callipygus and C. dorsalis. Finally, night
transects can be dangerous where elephants, gorillas, and
gun hunters are numerous.
Between December 1993 and October 1994 I conducted a
total of 97.7 kilometers of surveys along a set of transects
established by the World Bank-funded Projet d'Amenagement de
Ressources Naturelles between Mossapoula and Bayanga (World
Bank, 1990). The transects are four parallel and straight
paths roughly two meters wide, each two kilometers in length,
and 500 meters apart. The perpendicular paths connecting
the ends of the four parallel trails--two 500 meter sections
at the east end, and a single 1,500 meter section at the
west end--were also censused. Figure 3.5 shows the location
of line transect surveys, as well as the net hunt censuses
described below. Two observers walked together at a pace of
1-1.5 kilometers per hour, beginning between 10 a.m. and
noon, and covering 5-6 kilometers per day. For each animal
seen or heard, I recorded the following information:
species, number, angle, perpendicular distance from
transect, animal to observer distance, forest type, and
time. Duikers often whistled in alarm as they flushed.
Location of Line Transect and Net Hunt Surveys
The method makes the following assumptions: 1) all
animals on the transect line are seen; 2) each animal's
position is fixed before it moves away from the observer; 3)
no animal is counted twice; 4) distance measurements are
exact; and 5) sightings are independent events (Anderson et
al., 1979; Burnham et al., 1980; Eberhardt, 1978). All
assumptions were probably violated in practice. Duiker
flight responses depend on the vegetation. Where the
understory is relatively clear, duikers tend to move away
quietly and are not observed at all, or they flush further
away from the observer than their original position. Where
the understory is thicker, duikers more often freeze and
flush when the observer is very close, or remain hidden.
Duikers, and especially the nocturnal bay duiker C.
dorsalis, may hide in thick brush in the middle of the day
when most censuses were conducted. Angle and distance data
are estimates and were not measured exactly. Finally the
sample size for all species is too small for reliable
density estimates.8 Nevertheless, I present the
information because no other data are available on duiker
population densities for the Bayanga region (Table 3.4). No
A. africanus were encountered.
Population density is calculated using the following
formula (Whitesides et al., 1988):
D = (N 1000) / 2LW
The width of the census path W is two times the mean
sighting distance for each species, assuming that the same
number of animals beyond this distance were seen and
included as were missed within the sighting distance. Two
alternative sighting distances are used in the table above:
W1 is the perpendicular animal-to-path distance, and W2 is
the animal-to-observer distance. The differences in density
'Buckland et al. (1993) recommend a minimum sample size
of 60-80 individuals.
estimates according to the two sighting distances are
statistically significant for C. monticola (Wilcoxon
matched-pairs signed-ranks test, T, = 0, p < 0.01).
Table 3.4: Estimated Population Densities
from Line Transects (animals/km2)
N L E W1 SD (+) D1
C. monticola 33 97.7 0.34 9.03 7.57 18.70
C. callipygus 4 97.7 0.04 18.25 9.44 1.12
C. dorsalis 1 97.7 0.01 20.00 -- 0.26
N L E W2 SD (+) D2
C. monticola 33 97.7 0.34 16.11 9.36 10.48
C. callipygus 4 97.7 0.04 22.00 13.49 0.93
C. dorsalis 1 97.7 0.01 20.00 -- 0.26
Notes: N = number of individuals seen
L = length of transect (km)
E = encounter rate (individuals/km)
W1 = mean animal to path distance (m)
W2 = mean animal to observer distance (m)
D1 = population density (individuals/km2) based on animal to
D2 = population density (individuals/km2) based on animal to
SD = standard deviation of W1 and W2 respectively.
Although the transects covered both mixed (8,325 meters
S80 percent) and monodominant Gilbertiodendron dewevrei
forest (2,175 meters 20 percent), only two observations (5
percent), both of C. monticola, were in monodominant forest.
The transect area was regularly visited by net hunters from
Mossapoula, as well as by residents of both Bayanga and
Mossapoula seeking other forest products. Therefore human
disturbance was high, resulting perhaps in low actual
densities. Transect surveys may also underestimate actual
densities at this site if animals are wary and avoid
detection by census takers.
Net hunt encounters
In addition to the line transect censuses, I have also
estimated population densities based on encounters during
net hunts from Mossapoula and from forest camps (Table 3.5).
Ichikawa (1978) also used encounters within the enclosed
circle of nets to estimate population densities for C.
monticola of 70-120/km2. Other researchers have censused
duiker populations using groups of observers with nets,
setting the nets randomly and counting only the animals
inside the enclosed area (Dubost, 1980; Hart, 1985; Koster
and Hart, 1988). However, because I was observing hunters,
the census path was not random: they do not hunt in
Gilbertiodendron dewevrei forests or in marsh/swamp
forests.9 And within the mixed forest where they hunt,
they encircle and search areas with patches of thick brush
or treefalls, where animals are more likely to hide.
9In general, Gilbertiodendron dewevrei forest has a
very open understory, with few hiding places. Marsh and
swamp forest is too thick and wet for net hunting.
Table 3.5: Estimated Population Densities
from Net Hunt Encounters (animals/km2)
<5 kms (N=39 hunts)
-1 n LrmsQ
10-15 kms (N=6 hunts)
Notes: N = number of animals encountered (captures and
escapes) by the entire net hunting group: N1 = encounters
inside the net circles; N2 = total encounters during hunt.
D = population density (individuals/km2). D1 is based
on the area inside the net circles. D2 is based on the
total area searched by the net hunting group, assuming a
path width between one and two times the net circle
diameter, and a path length based on the net circle diameter
and a 100-200 meter distance between casts.
10-15 kms (N=6 hunts
The first density estimate (Dl) is based on the area
inside the circles enclosed by the nets. The area is
determined by the number of nets used per hunt (maximum 20),
an average net length of 18.27 meters (N=54), and the number
of times the nets are set. I assume that all circles during
a given hunt are the same area, but the area varies between
hunts according to the number of nets. The number of
animals "censused" includes all captures and escapes from
inside the circles. I have excluded occasions when an animal
was seen first, and the nets were then set to capture that
The second density estimate (D2) is based on the total
area searched by the net hunters. In practice, the width of
the search path varies considerably: at times the hunting
group is close together near the nets, at other times the
group is spread over a considerable area as individuals lag
behind or detour to gather other forest products. I
calculate the daily path width using two alternative
measurements: one and two times the diameter of the net
circle. The distance between casts also varies. I have
calculated the daily path length according to the circle
diameter, the number of times the nets are set, and two
alternative distances between sets: 100 and 200 meters.
The number of animals censused includes all animals seen
during the hunt. The result for each hunt is a range of
densities according to alternative path width and length
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