This issue inaugurates the publication of a newsletter
serving the IUCN/SSC Sirenia Specialist Group. I have taken on
its editorship at the request of group chairman Robin Best, and I
look forward to working with the entire sirenian research and
conservation community to disseminate news and useful information
in as timely a manner as possible. I have long felt a need for
such an organ of communication, and believe it can help to
increase the tempo of research and protective efforts on behalf
of our favorite animals at a time when the tempo of threats to
their survival is all too obviously increasing.
The present publication had a short-lived forerunner, the
Dugong Newsletter of the Townsville group, of which unfortunately
only a single issue appeared (in 1979). I intend to at least
equal the commendable breadth of content envisioned for that
newsletter. Sirenian-related news of all sorts will be welcomed -
on biology and ethnobiology, conservation and native concerns,
anecdotal observations and new techniques, literature citations,
abstracts and reviews, letters and editorials, and anything else
you wish to communicate to your colleagues. Those who know my
interests will not be surprised to find items of a
paleobiological nature also. The past is not purely of
antiquarian concern; it can rise either to help or to haunt us,
as shown by the review in this issue.
This will be an informal forum, not to be considered
citable, formally-published literature; it will not be "peer-
reviewed", and contributions to it should not be quoted without
the written permission of the author. Certainly the opinions
expressed will be those of the writers and not necessarily those
of IUCN or other organizations. Therefore, I hope that
contributors will feel free to offer informal speculations and
ideas as well as news in the interest of rapid communication.
In the beginning, publication of two or three issues per
year can be expected. These will be sent gratis to members of the
Sirenia Specialist Group and, for the time being, to some others.
Later it may be necessary to institute subscriptions. Addresses
of those who are or may be interested in receiving Sirenews
should be sent to me. Its size, frequency of appearance, and
ultimately its success, of course, will depend on you and on the
volume of news you generate and submit. I am confident, however,
that we now have a critical mass of active sirenologists and
sirenophiles, and that this will be a fully self-sustaining
All material to be published in Sirenews should be sent
directly to me. The deadline for receipt of copy for the second
issue will be September 3, 1984. THIS IS THE ONLY NOTICE YOU WILL
For those who were expecting this newsletter to be called
The Siren, an explanation is in order. Dave Laist called my
attention to the fact that that name (complete with a manatee
logo!) has been preempted by a publication of the UNEP Regional
Seas Programme. Any who dislike the present title are strongly
encouraged to suggest a better one.
I thank all the contributors to this first issue, and
acknowledge the aid of IUCN, the U.S. Marine Mammal Commission,
the U.S. Fish and Wildlife Service, and the Howard University
Department of Anatomy in producing and distributing it. I welcome
this opportunity to serve you in your efforts to protect and
understand the unique animals to which we have devoted our
collective labors. DPD
SIRENIAN RESEARCH PLAN
In October 1983, a meeting was held at the U.S. Fish and
Wildlife Service Laboratory at San Simeon, California, to draw up
a series of sirenian research proposals for the utilization of
US$1 million as part of the United Nations Environmental
Program's Global Plan of Action for the Conservation, Management
and Utilization of Marine Mammals. Dr. Helene Marsh of the James
Cook University chaired the meeting, which was attended by P.
Anderson, K. Radway Allen (UNEP), R. Best, R. Brownell, Jr., and
The UNEP Global Plan puts forward a series of 39 immediate
and long-term Recommendations in five areas of concentration: (1)
Formulation of Objectives; (2) Regulatory and Protective
Measures; (3) Improvement of Scientific Knowledge; (4)
Improvement of Law and its Application; and (5) Enhancement of
Public Understanding. One of the 39 recommendations proposed that
a sum of $10 million be made available for the support of a
comprehensive research program: $6 million for cetaceans, $3
million for pinnipeds, and $1 million for sirenians. The San
Simeon meeting resulted in a 73-page prioritized list of 26
worthwhile sirenian research projects, including outlines of
objectives and cost estimates. Sixteen of these are studies of
distribution and status; the rest emphasize basic biology.
Projects in the first category are required in developing
countries where little or no work on sirenians has been done in
the past. On the other hand, the committee considered that
projects concerned with increasing knowledge of sirenian biology
will generally be most successfully developed as extensions of
existing projects to take advantage of the expertise of
experienced sirenian biologists and the facilities available at
their institutions. The report rightly stresses the potential
importance of the proposed program for ensuring continued support
for the three centers of sirenian research (Gainesville, Manaus,
and Townsville), whose survival is essential to world capability
to undertake research on sirenians in the future.
The fate of these proposals is uncertain. Dr. Radway Allen
advises that they were considered at a consultation in January
1984 between UNEP, FAO and other interested international
organizations. Since then, he believes that they have been
considered at discussions between UNEP and the permanent
representatives of its various member governments in Nairobi. The
proposals which the member governments are likely to support
will, apparently, be considered by the Governing Council of UNEP
in May of this year. In response to a query from one sirenian
biologist, Dr. Radway Allen says that he does not think the U.S.
withdrawal from UNESCO will affect the progress of the proposals.
The Fourth International Theriological Congress will be held
at the University of Alberta, Edmonton, Canada from 13-20 August
1985. The program will include 25 Symposia and 11 Workshops. One
of the Workshops will be entitled "Sirenia: Biology and
Conservation." It will take an entire day, including a plenary
lecture, poster session, five half-hour papers (selected on the
basis of submitted abstracts), and a round-table discussion. The
papers should deal with sirenian biology emphasizing implications
This will be the first workshop to be held on the Sirenia as
a whole, and should be a unique opportunity for interested
biologists to exchange information and ideas. The convenors
(Marsh, Best, Rathbun, and O'Shea) plan to have many more posters
than platform presentations, in order to stimulate discussion and
personal contact. They hope to obtain travel funds for attendees,
particularly from Third World countries.
Those interested should write Dr. Helene Marsh, Zoology
Department, James Cook University, Townsville, Qld. 4811,
Australia. State whether you wish to present a poster or a paper
and whether you will require travel funds for your attendance.
The deadline for provisional registration is 31 May 1984.
MARINE MAMMAL WORKSHOP
The First South American Workshop on Marine and Freshwater
Mammals will be held in June or July 1984 in Buenos Aires,
Argentina, one week prior to the IWC meeting in the same city.
Argentine, Brazilian, Chilean, and Uruguayan specialists on
cetaceans, sirenians, otters and pinnipeds will present over 25
papers on biology and conservation of southwest Atlantic and
Amazonian species. Researchers and conservationists are invited
to participate in several discussion meetings. For information,
write Lic. Hugo P. Castello, Museo Argentino de Ciencias
Naturales, Av. A. Gallardo 470, 1405 Buenos Aires, Argentina.
AUSTRALIA (Shark Bay)
In a recent report to the Fund For Animals (Australia), Paul
Anderson made numerous recommendations for future research on
dugongs at this unique and vitally important site. In addition to
detailing the many areas of dugong biology still inadequately
understood, he included the following observations: "Studies of
the seagrasses conducted in 1981-82 suggest problems of forage
quality (but not quantity) in winter that need further
clarification.... They also suggest that there may be a
quantitative problem (overgrazing) with high-quality summer
forage on the Wooramel delta, and that this might be the factor
limiting dugong numbers at present.... Best (1983) has recently
published evidence that Amazonian manatees may fast for up to
seven months during the unfavorable (dry) season. While dugongs
clearly feed on Amphibolis (as indicated by both observed
ingestion and fecal production) the feeding appears to be
inefficient and the forage quality low at a time when energy
desirable for thermoregulation may be high. Studies (perhaps in
"captivity" in one of the Shark Bay lagoon areas) of actual food
intake are needed to test the hypothesis that dugongs in Shark
Bay may be on a semi-fast during the winter months.... Work in
1983 has confirmed that local movements occur in response to
weather patterns which cool inshore waters in the preferred
winter habitats, and has shown that the effects of these
movements on foraging efficiency can be studied."
Paul also reports that Shark Bay is being considered for
both World Heritage and National Park or Marine Reserve status.
Permanent protection for this site is vital and certainly should
receive the unqualified support of the Sirenia Specialist Group.
Paul hopes to get back to Shark Bay himself, "tentatively around
1986-87", and continue his work there.
Helene Marsh reports that there are now five biologists
affiliated with James Cook University who have a research
interest in dugongs:
George Heinsohn has temporarily defected to studying
cetaceans while he is on sabbatical with Dr. Ken Norris at the
University of California at Santa Cruz.
Helene Marsh is completing her study of dugong life history
and reproductive biology based on the study of specimens obtained
from over 500 animals killed in indigenous fisheries or
accidentally drowned in nets. A large proportion of this material
was collected by the Papua New Guinea Division of Wildlife Dugong
Project. The study indicates that dugongs have a maximum lifespan
of up to 60 or 70 years, a minimum pre-reproductive period of
nine or ten years for both sexes, a usual litter size of one and
a mean calving interval variously estimated for several
populations as three to seven years. Population simulations using
various combinations of these life history parameters indicate
that even with a very low schedule of natural mortality, an
unharvested dugong population is unlikely to increase at a rate
of more than about 5 per cent per year.
Calving, ovarian activity and testicular activity are all
diffusely seasonal. There is evidence for significant
fluctuations between years in the proportion of both mature
females and males in breeding condition and in the apparent
pregnancy rate. Three papers are in press from this work in the
Australian Journal of Zoology and another two should be completed
late in 1984.
Brydget Hudson, former leader of the Papua New Guinea Dugong
Project which was discontinued in late 1981 due to lack of funds,
is now enrolled in a joint Zoology/Geography master's program at
James Cook University. She is writing up her work on the PNG
Dugong Conservation and Public Education Programme, including the
development of the Maza Wildlife Management Area based on the
dugong fishery at Daru in Torres Strait. Brydget advises that she
has a VHS video copy of the excellent 50-minute documentary "The
Kiwai: Dugong Hunters of Daru", which was produced by the
Australian Broadcasting Commission and which she is prepared to
lend for meetings, etc. This film has already had significant
impact when shown in dugong-hunting communities in Australia, PNG
and Vanuatu and is an excellent public education tool.
Andrew Smith, a Ph.D. student at the University's Sir George
Fisher Centre for Tropical Marine Studies, is collecting and
collating information on the indigenous knowledge of the biology
and behavior of dugongs as part of his study on the current and
traditional use of marine resources by Aboriginal communities on
the east coast of Cape York Peninsula (Queensland, Australia). He
is also studying the indigenous exploitation of dugongs in the
Starcke River region to provide a basis for possible management
strategies. His work is funded by the Great Barrier Reef Marine
Janet Lanyon, a student at Monash University, Clayton,
Victoria, has begun a Ph.D. project (under Gordon Sanson and
Helene Marsh) on the functional morphology and nutrition of
dugongs in relation to seagrasses. Her field program is based at
James Cook University. Janet is sampling tropical seagrasses in
dugong feeding areas on a seasonal basis to study their
abundance, species diversity, growth patterns, development, and
nutritional quality. She is also investigating the functional
morphology of the dugong dentition in relation to its seagrass
diet and examining seagrasses from an ultrastructural perspective
to relate this structure to the digestive processes employed by
the dugong for plant breakdown. This study of feeding biology may
prove to be important in explaining the seasonality of dugong
reproduction. Janet would be most interested to hear from anyone
who has attempted a similar study of manatees.
Torres Strait Survey. An aerial survey to determine the
relative density of dugongs in Torres Strait was carried out in
November 1983 by scientists from the Papua New Guinea Division of
Wildlife and James Cook University. The project was funded by the
Australian National Wildlife Service. The survey was carried out
as a strip census using a survey design similar to that developed
for kangaroos by Dr. Graeme Caughley.
The survey returned a minimum estimate of only 1455 + S.E.
276 dugongs for this area. It is not possible to convert this
minimum estimate into an absolute population estimate because the
proportion of dugongs which are actually sighted under survey
conditions has not been calibrated. However, given the generally
excellent survey conditions and the experience of the survey
team, it seems highly unlikely that there could be enough dugongs
in the area to sustain the level of hunting that allegedly took
place in 1983. The Islanders themselves estimate that in 1983
they killed on the order of 1000 dugongs, many of which were
caught by indigenous fishermen operating crayboats with freezer
facilities. This estimate is not confirmed, and Wallace
MacFarlane, of the CSIRO Traditional Fisheries Programme (see
below), believes that the true figure is more likely to be 400-
Population simulations indicate that even with the most
optimistic combination of life history parameters, 9000 dugongs
would be required to sustain an unselected annual harvest of 500.
If the life history parameters suggested by the 450 specimens
collected from the Daru harvest are correct, the population
required would be 29,000 animals.
There is considerable evidence that dugong numbers have
declined dramatically in Torres Strait in recent years. For
example, the number of animals passing through the Daru market
has declined from 207 in 1979 to less than 50 (probably on the
order of 20) in 1983. In contrast, the fishing effort (measured
by the number of sea turtles passing through the market) has
increased (see also CSIRO Traditional Fisheries Programme,
Cooperative management initiatives between Australia and
Papua New Guinea are clearly urgently required if dugongs are to
be prevented from becoming rare or extinct in this area, which
probably contains the most extensive subtidal seagrass beds yet
Plans for 1985. The James Cook group plans to concentrate
research efforts for 1985 on refining aerial survey methodology
in order to develop methods to track the numbers of dugongs at
various locations in northern Australia over time. The results of
this research will be used by the various management agencies to
assess the efficacy of their programs and to suggest sustainable
catch quotas to indigenous communities.
CSIRO Traditional Fisheries Project. Dr. Bob Johannes and
Wallace MacFarlane are investigating the Torres Strait Islanders'
traditional fishing practices, including the harvest of dugongs
and sea turtles. Preliminary figures from three communities
indicate that the number of dugongs being caught is now
substantially less than the catches Nietschmann recorded from the
same communities in 1976-78.
Northern Territory Conservation Commission. Peter Bayliss
recently completed the first of a series of aerial surveys aimed
at determining the status of dugongs along the Northern Territory
coast. During his survey he conducted preliminary experiments
aimed at refining aerial survey methodology and at developing
factors to correct for the animals missed by observers during a
survey. A program to salvage specimen materials from dugongs
being killed by indigenous hunters in the Northern Territory is
also being developed.
Robin Best reports progress at INPA in Manaus "even in the
face of the country's drastic economic situation" (the following
is quoted from the IUCN/SSC Newsletter, Feb. 1984):
"Firstly, donations of Cr$15.4 million (US$26,000) from the
Amazonas State Government and Cr$20 million (US$33,500) from the
IBM company made it possible to construct permanent research
pools for our 14 captive-reared manatees and also for river
dolphins and giant otters (we already have one male). This helps
our research greatly as we can now maintain reproductive groups
of manatees together and hopefully can expand our research on
these into the area of reproductive endocrinology and finally
captive breeding. We expect that through the more visible tanks,
etc., the interest generated by being able to see the animals in
the tanks will bring more local and government support of our
research. We hope to arrange a visitation programme of visits for
school children so that they get the 'conservation message' via
the manatee project.
"Secondly, the Brazilian Institute for Forestry Development
(IBDF), the government agency responsible for fauna protection,
is currently sponsoring a campaign for the preservation of
manatees, with our collaboration, including television ads, radio
programmes, posters, and booklets. This is the first time such a
large-scale programme has been drawn up for manatees in this
"Lastly, we were able to introduce a further 12 manatees to
the first hydroelectric reservoir of the Amazon, Curua'-una near
Santare'm, making a total of 42 manatees introduced there since
1980. Most of these animals were captured by us on the Rio
Japura', some 1000 km distant from the reservoir, and had to
be barged down river for 7-10 days and then trucked 80 km to
the damsite. We have put WWF(US)-provided radio-transmitters on
all of them and have reams of data now on daily and
seasonal movements and social interactions, as well as habitat
usage. A few manatees have come from the fiscalization efforts
of IBDF as this species is protected by the Brazilian Endangered
Species Act of 1971. The Brazilian Electric Company (ELETROBRAS)
is extremely interested in the continuation of this project and
is including the next three hydroelectric dams in the same
programme. These new man-made lakes, although extremely damaging
in terms of habitat destruction for terrestrial fauna, may at
least be good for manatees in that large new stable habitats are
being created and are relatively easily protected, especially as
the lake-shore colonists are generally from NE Brazil where
agriculture, and not fishing, is their primary occupation."
The following news items were contributed by the Gainesville
1983 Manatee Mortality in Florida. The mild temperatures
in 1983 resulted in relatively few manatee deaths in Florida.
Eighty dead manatees were reported and 78 were recovered and
examined at necropsy. Thirty-nine were examined at the University
of Miami and 36 at Gainesville; the remaining 3 were necropsied
at a newly established field facility on the J.N. "Ding" Darling
National Wildlife Refuge near Ft. Myers, Florida.
The causes of death for 1983 and the number of cases for
each factor were: collision with a boat or barge, 14; crushed or
drowned in floodgates or canal locks, 7 (5 in floodgates, 2 in
locks); entrapment in culverts, 4; entanglement in crab trap
line, 1; dependent calves, 18; natural factors, 5 (2 of
pneumonia, 2 of enteritis and starvation, 1 of congestive heart
failure); undetermined, 29 (mostly too decomposed for accurate
1984 Cold-related Mortality in Florida. During January
1984 a record 33 carcasses of manatees were recovered in Florida,
with one additional case from North Carolina. Six died of various
human-related causes, 2 were dependent calves, and 10 died of
undetermined causes. Cold stress was thought to be responsible
for 16 of the deaths. Florida experienced a severe, record-
breaking freeze in late December 1983, and cool weather extended
through early January. Manatee mortality was consistent with
previous findings: most cases involved smaller-sized, sexually
immature manatees, often marked by a cachetic state with low body
fat reserves and an absence of food in the upper gastrointestinal
tract. Most were not recovered in the immediate vicinity of warm-
water discharges or springs where manatees typically take refuge
in winter. Precise causes of death remain undiagnosed, but
circumstantial evidence suggests that metabolic drains on
manatees inexperienced at using warm water refuges may be great
enough to result in hypothermia and subsequent death without
significant pathological lesions.
In January 1984, deaths were most prominent in two areas:
the lower St. Johns River and other waterways in Duval, Nassau,
Clay, and St. Johns Counties in northeastern Florida, and Lee,
Collier, and Charlotte Counties in southwestern Florida.
Carcasses recovered in early January typically were fresh and
were sunk on the bottom, visible only at low tide. Those
recovered in middle and late January showed advanced
decomposition and were afloat. This indicates that most of the
mortality took place in the early part of the month when water
temperatures were lowest.
Cataloging Manatees in Florida. Photographs of manatees
distinctively marked either naturally or by propeller wounds have
been assembled in a state-wide identification catalog. A total of
652 manatees have been cataloged based on photos taken at nine
different aggregation sites around Florida. Brevard County has
been monitored for five years; Jacksonville, Riviera Beach, and
Port Everglades for three years; and Ft. Myers and Tampa Bay for
only one year. Blue Springs and Crystal River have been monitored
for nearly a decade.
Resightings of cataloged individuals have documented summer
site fidelity in Brevard County and winter site fidelity at
Jacksonville, Riviera Beach, and Port Everglades. Several
manatees, however, have changed winter aggregation sites both
within and between winter seasons. Long-term resighting data for
some individuals have confirmed a seasonal north-south migration
along the eastern coast of Florida. Movements in excess of 600 km
have been documented for two individuals that travelled between
Port Everglades and Jacksonville over two and three year periods,
respectively. These findings suggest that manatees along the east
coast do not form discrete subpopulations.
Status of the West Indian Manatee in the Northern Gulf of
Mexico. A review of historical records indicates that manatee
numbers have declined in Texas, but increased in Louisiana and
Mississippi. This is due to their extinction in Mexico and
dramatic increase along the southern Big Bend coast of
northwestern peninsular Florida. Their distribution in the latter
area is related to their need for warm water and submerged salt-
and freshwater food plants. The spring-fed headwaters of the
Crystal and Homosassa Rivers are important warm-water winter
refuges, with nearly 90% of the same individuals returning each
winter. The estuaries and grass beds associated with these two
rivers and the Suwannee, Withlacoochee, and Chassahowitzka Rivers
are the principal summer habitats. The Suwannee and Crystal
Rivers are used more heavily than the others. Low human-caused
mortality, high fecundity, some immigration, and high site
fidelity are responsible for the increasing numbers of manatees
using the south Big Bend coast. Since this region has experienced
relatively little development compared to the rest of Florida, it
offers the best long-term future for the manatee in the United
New Radio-tag Being Developed for Manatees. The U.S. Fish
and Wildlife Service Sirenia Research Project in Gainesville is
putting the final touches on an entirely newly designed radio-tag
assembly that will enable biologists to track manatees in salt
water habitats. Because salt water attenuates radio signals, the
objective of the new attachment is to keep the transmitter
antenna above the water surface as much as possible. This has
been achieved by using a modified marine turtle transmitter
housing designed by the Service's Denver Wildlife Research
Center. The transmitter floats, and is attached to a belt around
the manatee's peduncle by a 2-meter-long flexible plastic tether.
Another innovative feature of the new assembly is the buckle
used to secure the belt around the peduncle. All past tagging
efforts have required a manatee to be measured before being
fitted with a custom-sized belt. The new buckle allows belts to
be fitted and then locked in place without knowing the
circumference of the peduncle.
Twinning in the West Indian Manatee. On 24 April 1983 a
very large dead manatee (M-331) was reported to the Sirenia
Project in Gainesville. The 375 cm long, 1161 kg female was
necropsied the next day. Cause of death was evident from the
large, fresh propeller wounds on the back and tail. Internal bone
damage and hemorrhage were consistent with observations in other
cases of collisions with large boats.
External examination revealed a greatly distended abdomen
and vulva. Mucus and bloody fluid were exuding from the dilated
vagina. Internally, the animal had very heavy fat deposits and
was moderately decomposed. The GI tract was full of aquatic
vegetation. Organ configuration was unremarkable, except that the
greatly distended uterus occupied nearly half of the abdominal
cavity. It contained two full-term fetuses, both female and both
weighing 39 kg, one 135 cm and the other 132 cm long. Although
twinning in marine mammals is rare, it has been suspected to
occur occasionally in manatees. Gumilla, in El Orinoco Ilustrado
(1745), reported seeing two 25-pound fetuses taken from a female
manatee, but this is the first case of twinning in sirenians
confirmed in modern times.
The Fish and Wildlife Service also reports that the Proposed
Research/Management Plan for Crystal River Manatees was
distributed for public review at the end of February 1984. This
plan, written by Jane Packard and associates at the University of
Florida and based on a concept originally developed and funded by
the Marine Mammal Commission, is intended to provide a framework
for meeting the present and future needs of the Crystal River
manatee population in concert with the needs of the area's
developing human community. It summarizes present information
about the manatee population, identifies gaps in the existing
data base, describes potential threats to the Crystal River
environment, and recommends research consistent with maintaining
planned public use of the area.
The proposed plan has no regulatory or legal standing.
Rather, it is intended to serve as a reference source and guide
for local decision-making in the area. In accord with a
recommendation contained in the plan, the Fish and Wildlife
Service is considering the sponsorship of a Steering Committee,
under the leadership of local officials, to work towards
implementation of the plan. This committee would serve as a forum
for broad public and private involvement in the effort, and make
recommendations for future updates of the plan.
The plan has an innovative design, and consists of three
separate documents: (I) an illustrated, nontechnical booklet
of 31 pages which summarizes the information in the plan; (II)
the plan itself (250 pages), intended for agencies and
professional people involved with planning, research, regulatory
actions, etc., in the Crystal River area; and (III) a 350-page
"compendium" of research papers (mostly previously published) and
review comments used as the basis for the information and
recommendations in the plan.
The Service has distributed the proposed plan for review to
interested agencies, organizations, and professional individuals
involved with management of manatees and other resources of the
area. Copies will also be available for public review at public
libraries in Citrus and Levy Counties, Florida. However, due to
printing costs, copies of volumes II and III are not presently
available on request, and probably will not be in the future
unless there is great demand for them. Single copies of Volume I
(the summary), which contains the central elements of the plan
along with background information on manatee biology and research
efforts, will be provided to anyone who requests them from the
Endangered Species Field Station, U.S. Fish & Wildlife Service,
2747 Art Museum Drive, Jacksonville, Fla. 32207.
Dean Treadwell, wildlife ecologist with the USAID Gambia
River Basin Study, reports the following in a letter to Robin
Best, dated 24 January 1984:
"Since I have spent most of my time thus far up in eastern
Senegal and the Guinea highlands, my manatee information is
minimal. I have heard of sizable numbers (10-20?) spotted from
the air in the Sine Saloum Delta (the drainage immediately north
of the Gambia). Most of the sightings in the Gambia thus far
(n=3) appear to be well up-river away from any sea water
intrusion. You also inquired into captive manatee in 1980,
there was one at the zoo in Bamako, Mali (Niger River Basin)."
The Gainesville group reports that during a recent aerial
and interview survey for manatees in Haiti, they were found to
still occur near the mouths of the larger rivers, especially
along the northern coasts of both the northern and southern
peninsulas. However, they are still hunted (illegally) for their
meat and their numbers appear to be greatly reduced compared to
the adjoining Dominican Republic and other islands in the Greater
Colin Bertram sent a copy of a report by R.V. Salm and G.
Usher entitled "The magical tears of the dugong" (WWF Monthly
Report, December 1983, Project 3108, Indonesia Marine
Conservation, pp. 677-679). It says that good numbers of dugongs
remain in only two provinces of Indonesia: Maluku and West Irian.
WWF/IUCN are supporting a project in Maluku for the establishment
of marine reserves which will include protection for dugongs.
Three reserves have already been declared, at Pulau Pombo, Pulau
Kasa, and Pulau Banda. A proposed reserve at Aru Tenggara in the
Aru Islands is particularly important because it has what is
possibly the largest population of dugongs in Indonesia. Toward
the end of 1979 dugongs were relatively numerous in the Aru
Islands. However, they were intensively hunted and an estimated
1000 animals were killed each year, despite protection by a
ministerial decree. They are harpooned at night in shallows, and
caught accidentally in shark nets. The meat of an adult can fetch
the fisherman up to US$33, half the average annual income of a
local fisherman. Dugong tusks can fetch double the price of the
meat; they are used for cigarette holders believed to have
aphrodisiac properties. Young dugongs, caught after their mothers
have been harpooned, are kept alive out of the water and their
"tears" collected drop by drop. A cotton swab dampened with these
tears sells for US$1 and is thought to bring good luck,
prosperity, and success with women. The Aru Tenggara Reserve will
protect both dugongs and turtles; an estimated 3000 to 6000 green
turtles are killed and 2 million eggs are collected each year in
the Aru Islands.
The Nowruz Oil Spill. A major oil spill in the Arabian
Gulf began in January 1983 with accidental discharge from a
damaged well of the Nowruz oil field, located in Iranian waters.
In March 1983 two additional platforms were damaged as a result
of military activities in the area and the wells set on fire.
This spill and some of its ecological consequences are the
subject of a report published in October 1983 by the Saudi
Arabian Meteorology and Environmental Protection Administration
(MEPA), and entitled "The Nowruz Oil Spill, January 1983: The
Saudi Arabian Response. Interim Report No. 1" (15 pp.).
According to the MEPA report, the discharge rate in August
1983 was estimated at around 4500 bbl/day. One well was capped in
September, reducing the discharge to about 2500 bbl/day. In
addition, oil was burning at two wellheads at the time of the
report; but the fire was reaching a critical level near the water
surface, and if it were extinguished, a total output to the sea
of 16,000 bbl/day could be expected. The total oil released to
Gulf waters up to 1 Oct. 1983 was about 900,000 bbl (38 million
U.S. gallons). Up to half of this volume, especially the low
molecular weight compounds, may have been lost by evaporation and
other dispersion processes.
Observation and control of the discharge have of course been
hampered by its location in a war zone, and confounded by the
existence in Saudi Arabian waters of other sources of discharge
such as industrial spills, ships pumping ballast, and a well in
the Khafji field which had been burning and polluting the sea
surface for 18 months as of March 1983. During the first half of
1983, rafts of weathered oil hundreds of meters long, oil sheen
covering many square kilometers, and numerous tarballs were blown
onto the coasts of Saudi Arabia, Bahrain, Qatar, and eastern
regions of the United Arab Emirates. As weathering proceeded,
many of the oil mats evidently sank and carpeted sizable areas of
the sea floor.
The MEPA report states that "a dugong population of 50-60
specimens was estimated in 1979 for the Gulf of Salwah,
associated with the high salinity seagrass beds.... From early
March to mid-April, dead invertebrates, fish (600+)(pelagic,
reefal, benthic), seasnakes (1500+), turtles (56) (hawksbill,
green), birds (200+), dugong (32) and porpoises (33) were found
on Saudi Arabian Gulf coastlines.... Mortality and stress in
coral, a major monoculture algal bloom, and an apparent reduction
in reef flat grazer populations were observed.... No further
"marine animal kills' have been observed in Saudi Arabian waters
since mid-April nor have similar 'kills' been reported from other
Gulf states, except for two dugong and some dead fish in
Bahrain." About 50% of the dead dugongs are said to have been
juveniles. "These surveys did not include all the Saudi Arabian
Gulf of Salwah shore and no information is available from Qatar.
Two live dugong were sighted by aerial surveillance in late
April. The MEPA assessment is that the Gulf of Salwah dugong
population has been reduced to a dangerously low and probably
non-viable level and may very well become extinct."
In view of the foregoing observations, including
observations of oiled birds, and an admission that coral
mortality was probably directly due to Nowruz oil derivatives, it
is most surprising to find the following statement in the MEPA
report: "Coincident with the 'marine animal kill' reports was the
entry of oil sheen and tarballs into and progressing through
Saudi Arabian waters. However, there is no proof that the 'kill'
was a result of Nowruz oil or its chemical/physical effects on
Gulf waters." If this statement is meant to imply that a causal
connection between oil pollution and the kills is in doubt, then
the statement appears indefensible and a more realistic
assessment by MEPA would seem to be in order.
International efforts to monitor, halt, and clean up the
spill are said to be continuing. The report notes in passing that
"the sightings of mines in Saudi Arabia/Bahrain/Qatar waters has
introduced an element of surprise to this program."
The report concludes that "irrespective of the causal factor
involved in the death of the dugongs and hawksbill turtles, these
populations have been severely affected. A faunal replenishment
program is included in the Saudi Arabian Plan of Action for the
Nowruz oil spill. This is aimed at evaluating and effecting a
population "transplant' to re-establish and maintain both
endangered species in Gulf waters, after effective capping of the
wells." It is not explained how such a "transplant" might be
carried out, nor where the transplanted animals might be taken
from. This situation bears watching by all international wildlife
agencies, in regard to both the continued danger from the spill
itself and the danger that ill-advised "transplants" or other
well-intentioned remedial measures might aggravate rather than
alleviate the harm already done.
Sirenian research goes on even here, far from the sunny
tropics. Daryl Domning and Lee-Ann Hayek's paper on horizontal
tooth replacement in Trichechus inunguis is finally due for
publication this spring, more than two and a half years after the
MS. was accepted by Mammalia (prospective contributors to that
journal take note). This will just about exhaust the backlog of
manuscripts stemming from Daryl's two years in Brazil (1976-78),
and he is now once again putting most of his research effort into
With Larry Barnes and Clayton Ray, he reviewed the status of
fossil marine mammal studies for the new Society for Marine
Mammalogy's meeting in Boston in November 1983; the MS. will
appear in the first issue of the Society's new journal. North
Pacific sirenians still keep surfacing: Domning and Tom
Deme're' report new specimens of Hydrodamalis cuestae from
San Diego County, California, including the partial skull of
the largest individual sirenian ever found (Trans. San Diego Soc.
Nat. Hist., in press). Its direct ancestor, a new Late
Miocene species ("Dusisiren Species D" of Domning, 1978), has
been found in Japan and will soon be described; its well-
preserved flipper supports Steller's sometimes-doubted statement
that Hydrodamalis had no phalanges. And it can now be revealed
that sirenians once made it to the southeastern Pacific:
Christian de Muizon has discovered Early Miocene specimens of
Metaxytherium on the coast of Peru!
Daryl spent a very productive nine weeks of 1983 studying
fossils in European museums. As one result, he and Herbert Thomas
of Paris are straightening out the Old World Metaxytherium using
cladistic analysis (the mess they were in required drastic
measures!), as an adjunct to describing the Early Pliocene ones
from Sahabi, Libya.
Meanwhile, slow progress is being made toward making sense
of the West Atlantic and Caribbean dugongids. There are several
undescribed genera and species lurking in the Oligocene and
Miocene, most of them known only from tantalizing bone scraps.
Two of them are extremely small maybe less than two meters long
as adults. Most surprising is the repeatedly-encountered pattern
of sympatry, with two or even three taxa coexisting. Typically
there is a small one, a normal-sized one (3-4 meters long) with
very small tusks, and an equally large or larger one with big
bladelike tusks somewhat like Dugong all presumably competing
for the available seagrasses. Suggestions for niche-partitioning
strategies are earnestly solicited!
Richard Bradley, "The Pre-Columbian exploitation of the manatee
in Mesoamerica." (With Introduction by S.J. Thompson and Comments
by F.W. Lange, F.O. Loveland, B.L. Stark, B.L. Turner II, and
C.R. Wicke.) University of Oklahoma Department of Anthropology,
Papers in Anthropology 24(1): i + 82. 8 figs. Spring 1983. (Price
This is one of the more curious items in the annals of
sirenian bibliography, as much on account of its format as its
contents. The core of the work (pp. 13-58) is an M.A. thesis in
anthropology by Bradley. What is unusual is that it is sandwiched
between an editor's introduction (pp. 3-8) explaining
apologetically why the work was published, and critical comments
on it by five other anthropologists (pp. 61-82). The introduction
explains that while the research was based only on literature
surveys and a few informant interviews but no new excavations,
the lack of information on the topic and the "admittedly
speculative" but provocative conclusions justify dissemination in
order to stimulate discussion and, hopefully, additional research
effort. At least for being "willing to stick their necks out and,
if need be, take their lumps," the author and editors are to be
What, then, are the unorthodox ideas put forward so
gingerly? In brief: That "the Olmec had an intricate relationship
with the manatee"; that they may have used it as an important
protein source and may even have raised it in artificial lagoons;
that it served also as a religious symbol, the so-called "were-
jaguar" motif in Olmec art actually representing a manatee; and
that manatee calves may even have been ritually sacrificed.
On what evidence are these surprising conclusions based? In
regard to manatees, Bradley has done his homework fairly
thoroughly. The bibliography is up-to-date and even includes
several unpublished theses relevant to the topic. His background
summary of manatee biology and exploitation (pp. 14-31) is
detailed and no more inaccurate than the primary and secondary
sources presently available. The choice of topic is significant,
because the Olmec "may have been America's first civilization";
Bradley implies that a number of Olmec sites were founded as a
direct result of manatee exploitation and argues that "the
manatee may be partially responsible for the development and
expansion of the Olmec in Mesoamerica." The archaeological
evidence, however, is very scanty. Only a few sites in Belize,
Yucata'n, Guatemala, and Panama have actually yielded
manatee bones, and none of these, apparently, are Olmec
sites. San Lorenzo Tenochtitla'n, the site of most concern
to Bradley, produced no manatees among the faunal remains
excavated. (This he plausibly attributes to butchering at the
kill site and/or ritual return of manatee bones to the kill
site, as is done by modern Rama Indians in Nicaragua.) Nor are
harpoons known to have been used by the Olmecs (though they did
have fish spears and nets). Bradley is, in fact, forced to rely
entirely on speculation based on the (reasonably) presumed
former existence of the manatee in the area, its potential food
value to the human population, and the Olmecs' apparent heavy
reliance on aquatic rather than terrestrial food animals in
general. Under the circumstances, his detailed speculations
about hunting methods and social and economic organization
of Olmec manatee hunters are audacious, to say the least. But
he goes still further and surmises that, to avoid over-
exploiting the manatee resource, they resorted to rearing
manatees in artificial lagoons.
The purpose of an aqueduct and over 20 artificial lagoons at
San Lorenzo has not been satisfactorily explained. Discounting
suggestions that they served as ritual baths or for raising
crocodiles, Bradley proposes that they were used to hold and even
to breed manatees captured in nearby rivers and lakes. The
aqueduct and drain system may have provided a flow-through water
supply, and the captive manatees would have provided a reliable
year-round protein supply (assuming that their natural occurrence
in the area was seasonal, a point not documented) while allowing
conservation of the wild population. As commentator Stark points
out, however, this idea is not consistent with off-site
butchering and absence of manatee remains at San Lorenzo.
Moreover, says Turner, such waterworks were not specific to the
Olmec but were built throughout the Central American lowlands,
mainly for water collection, drainage, and agriculture.
If correct, Bradley's interpretation has serious
implications for present-day conservation strategies. Schemes for
raising manatees in captivity or semi-captivity, for meat or weed
control, have been repeatedly proposed over the past century. It
will be asked: If the Olmecs did it 3000 years ago, why can't we?
Therefore Bradley's ideas must be scrutinized with great care,
lest their uncritical acceptance by policy-makers further cloud
debates on the necessity of maintaining viable wild populations
and habitats. My own view has long been that, if the aim is to
increase numbers of manatees for human use, there is little point
to labor-intensive hand-rearing in tanks when manatees are quite
capable of feeding and reproducing themselves if left alone in
the wild, where they can be easily harvested when desired. In the
present case, we must ask further how many manatees the Olmecs'
lagoons would have held and whether a breeding stock of this size
could have produced an economically significant annual yield -
which I consider highly doubtful. If they were used merely as
holding tanks for captured animals, and if manatees were
otherwise seasonally unavailable, then Bradley's thesis becomes
more credible; but such a situation must be clearly distinguished
from captive breeding. Besides, it has yet to be demonstrated
that the lagoons were not simply reservoirs or fishponds and that
the Olmecs ever ate manatees at all.
Economically significant animals may or may not have
religious significance, and Bradley's case for the manatee's
importance in Olmec art and ritual is even weaker. As Erich von
Da"niken demonstrated, the highly stylized nature of
Mesoamerican iconography lends itself to imaginative
interpretations. Says Stark, "the eye of the beholder seems
eager to take up where the Olmecs left off." Wicke, the
art specialist among the commentators, is unconvinced
that manatees ever appear in Mesoamerican art, and the
biologist examining Bradley's arguments readily sides with Wicke.
Bradley's attempts to show similarities between manatees and
the "were-jaguar" motif are more than strained. He quotes one
verbal description (by Jones and Johnson) apparently without
realizing that it refers not to a manatee but to a manatee skull!
Also cited as a point of resemblance are the manatee's
"crescent-" or "crest-shaped eyebrows" a notion Bradley
may have formed from wrinkles visible in a manatee photo he
reproduces, but certainly not from any first-hand familiarity
with the beast. He makes much of "human-like" attributes of
manatees, repeating the fable that they nurse their young in
their "arms" while floating (?) erect half out of the water. From
such comparisons, he leaps to the wholly unsupported speculation
that manatee calves were sacrificed, and then suggests that "this
may have been the model for later instances of real human
I am relieved to report that the five anthropologist
commentators take a uniformly dim view of such undisciplined
fancy. The most trenchant observation is Turner's: "What issue
does the manatee thesis possibly resolve? What incongruent data
or interpretations is it meant to correct? Were the Olmec
occupying a fauna deficient zone? Is there evidence that they
consumed an enormous amount of protein, the source of which must
be identified? No. The rationale seems to be Bradley's
fascination with the species and the fact that Mesoamericanists
have not paid sufficient attention to its possible significance."
I agree. Sparking discussion is a worthy goal, but when the spark
is generated by pure imagination rather than evidence, it is
tantamount to crying wolf and invites the same response. Here
there is the additional though opposite danger, already noted, of
unwelcome repercussions on proposed management policies. Everyone
concerned with sirenian conservation and husbandry should be
acquainted with this publication, and prepared to counter with
biological facts the sort of well-meaning but ill-informed and
faulty reasoning it could encourage. DPD
Tissue samples of sirenians (skeletal muscle, liver, heart,
brain, heparinized blood) are needed for molecular studies.
Tissues need to be stored and mailed frozen, preferably in dry
ice. Donors will be acknowledged. Contact Hezy Shoshani, Dept. of
Biological Sciences, Wayne State University, Detroit, Mich. 48202
(313) 577-2865 or Morris Goodman (313) 577-1004.
The following are abstracts of papers submitted to the Fifth
Biennial Conference on the Biology of Marine Mammals, Boston, 27
Nov.-1 Dec. 1983.
Distribution of Freshwater Dolphins and Manatees in the
Upper Rios Negro and Orinoco (R.C. Best and V.M.F. da Silva). -
Observations of Amazonian manatees (Trichechus inunguis) and the
freshwater dolphins (Inia geoffrensis and Sotalia fluviatilis) on
the Rio Negro and headwaters of the Orinoco suggest that although
these two large river systems are linked by the Casiquiare Canal,
this canal has not been an important factor in the distribution
of any of these species from one basin to the other. Contrary to
the probably misinterpreted reports of von Humboldt (1838),
Amazonian manatees apparently do not occur in the headwaters of
the Orinoco or Rio Negro (above the mouth of the Rio Canberi).
Sotalia occurs in the lower reaches of both the Orinoco and Negro
rivers. Although common on the extent of the Rio Negro, we did
not observe any Sotalia from Sa-o Gabriel de Cachoeira, upriver
from the rapids of Camanans, through to the Orinoco, during our
boat trip from May 10-18, 1983. Inia, which has only once been
reported from the upper Orinoco, was frequently seen from Cucui
on the Rio Negro through the Casiquiare Canal and upstream on the
Orinoco at least as far as La Esmeralda. This Inia appeared to
be darker and smaller than the large pink Inias common on the
lower Rio Negro in the area of Manaus. The distribution patterns
of these species are discussed in relation to the geological
events leading to the separation of the Orinoco and Amazon
Manatee Deaths in Association with an Outbreak of Red Tide
in Lee County, Florida, During 1982 (R.K. Bonde). An outbreak
of red tide off Lee County, Florida is implicated as the cause of
a die-off involving 41 West Indian manatees (Trichechus manatus)
during the months of February, March, and April 1982. Carcasses
were examined in a broadscale cooperative effort enlisting many
researchers and pursuing many avenues of investigation to
eliminate other possible causes of death. Circumstantial
evidence linked this die-off with several normally unrelated
concurrent events: (1) the early winter dispersal of manatees
using the local power plant; (2) a failure of seasonal rains; (3)
a severe outbreak of red tide; and (4) a relatively large local
population of ascidians (tunicates). It is suspected that 37 of
the manatees examined died either directly or indirectly from
a neurologic agent, most likely derived from the red
tide organism, Ptychodiscus brevis. One likely route of
exposure involves the incidental ingestion of ascidians and other
filter feeding invertebrates by manatees feeding in seagrass
Influence of Feeding and Fasting on the Metabolism of the
Amazonian Manatee (Trichechus inunguis) (G.J. Gallivan and R.C.
Best). Understanding the energy flow through an animal
requires knowledge of the cost of assimilating energy and of
special metabolic adaptations to periods of environmental stress.
The present study was conducted to determine the metabolic cost
of digestion in Amazonian manatees, a species being evaluated
for aquatic weed control, and also to determine if this
species exhibits any special metabolic adaptation for the periods
of food deprivation which occur during the Amazonian dry season.
Based on metabolic rate, the cost of eating for two subadult male
manatees was 3.6 L 02/kg for grass (Brachiaria mutica) and 4.0 L
02/kg for water hyacinth (Eichhornia crassipes). Unlike other
marine mammals, there was no elevation of metabolic rate after
feeding. Given the prolonged passage time (7-11 days)
and hindgut fermentation of manatees this would suggest that
the cost of digestion is a component of the resting metabolic
rate rather than a single event. Two weeks of fasting caused a
22% decrease in metabolic rate. This was proportional to the
decrease in body weight, thus there was no change in the weight-
specific metabolic rate. Observations during the fast indicate
that manatees reduce their energy requirements primarily by a
reduction in activity.
Food Habits of the West Indian Manatee, Trichechus manatus,
in South Florida (D.A. Ledder). Gut contents were collected
from 84 animals over a five-year period in order to describe the
diet of T. manatus in south Florida.
Microhistological analysis was used to identify plant
species sampled from the stomach, duodenum, and cecum. A gross
analysis was also done to estimate the ratio of surface to
subsurface portions of the plants consumed.
Manatees fed in both fresh and salt water. The seagrass
Halodule wrightii composed the largest portion of the diet
(23.4%), followed by the freshwater species Hydrilla verticillata
(12.3%). Significant contributions were also made by the
seagrass Syringodium filiforme (8.9%), and the euryhaline species
Ruppia maritima (8.0%). Algae were found in significant amounts
in five of the animals, contributing 6.0% to the diet.
Subsurface portions of plants contributed more to the diet for
saltwater species (mean ratio of surface/subsurface portions =
46/54) than for freshwater species (86/14).
Manatee (Trichechus manatus) Reproduction in Florida (G.B.
Rathbun and J.A. Powell). Longitudinal records of free-
ranging individually recognizable manatees at clear-water winter
refuges in northern Florida were used to determine the timing of
several reproductive events. Mortality records and aerial survey
data were also used. The adult sex ratio is 1:1; gestation is
12-14 months; litter size is 1-2; the proportion of calves
in the population is about 10%; the average calving interval
is 2.4 years; the minimum age at first reproduction is 5
years; and there is a slight peak in mating activity during the
spring in northern Florida. These data suggest that manatees in
Florida may have a greater reproductive potential than was
Results of Winter Aerial Surveys of Manatees (Trichechus
manatus) Around Florida Power Plants in 1982-1983, and
Comparisons with Similar Surveys of the Previous Five Years (J.E.
Reynolds III, P.M. Rose, and J.R. Wilcox). Intensive winter
aerial surveys to assess manatee abundance and distribution
around selected Florida power plants have been done in a
relatively consistent manner for the past 6 years. In winter,
1982-1983, 930 animals were sighted during 7 surveys of 5 power
plant effluents, and 261 manatees were observed away from the
plants. These counts are the lowest in the 6 survey years.
Winter of 1982-1983 was warmer than the previous 5 winters, so
that low counts may indicate insufficient cold weather to
induce large numbers of manatees to aggregate at sites of
warm water. It should not be assumed that recent low counts of
manatees around power plants indicate a lower manatee population
Calves represented 10.0% of the total animals sighted in
1982-1983. An overall calving rate from all 6 years of surveys
being considered was 10.8%, as compared to a combined calving
rate of 9.1% for other manatee surveys. These rates are
statistically different, suggesting that the effluents are used
to a greater extent by females with calves than by other
manatees. By providing sanctuary for calves, the power plants
serve an especially valuable function.
[Editor's Note: The following compilation is intended to
emphasize publications appearing in 1983 and 1984, and includes
papers of that period which the editor was able to remember or
dig out of his files while compiling this newsletter. Some
significant pre-1983 papers are also included. Readers are
invited to submit references at any time, either new ones (post-
1983) or old ones of general interest which they think their
colleagues may have overlooked. Owing to space limitations,
abstracts of published papers will generally not be reprinted in
this newsletter unless there is significant reader demand for
Bengtson, J.L. 1983. Estimating food consumption of free-ranging
manatees in Florida. J. Wildl. Manage. 47(4): 1186-1192.
Best, R.C. 1982. Seasonal breeding in the Amazonian manatee,
Trichechus inunguis (Mammalia: Sirenia). Biotropica 14(1):
Best, R.C. 1982. A salvac,a-o de uma espe'cie: novas
perspectives para o peixe-boi da Amazo^nia. Revista IBM No. 14:
Best, R.C. 1983. Apparent dry-season fasting in Amazonian
manatees (Mammalia: Sirenia). Biotropica 15(1): 61-64.
Best, R.C., G.G. Montgomery, and M. Yamakoshi. 1982.
Avaliac,a-o de te'cnicas de ra'dio-rastreamento e marcac,a-o do
peixe-boi da AmazoAnia, Trichechus inunguis (Mammalia:
Sirenia). Acta Amazonica 11(2): 247-254.
Best, R.C., G. Ribeiro, M. Yamakoshi, and V. da Silva.
1982. Artificial feeding for unweaned Amazonian
manatees Trichechus inunguis. Internat. Zoo Yearbook 22: 263-267.
Best, R.C., and D.M. Teixeira. 1982. Notas sobre a
distribuic,a-o e "status" aparentes dos peixes-bois (Mammalia:
Sirenia) nas costas amapaenses brasileiras. Bol. FBCN (Rio de
Janeiro) 17: 41-47.
Bizzotto, B. 1983. Prototherium intermedium n. sp. (Sirenia)
dell'Eocene Superiore di Possagno e proposta di revision
sistematica del taxon Eotheroides Palmer 1899. Mem. Sci.
Geol., Ist. Geol. Min. Univ. Padova 36: 95-116.
Bonde, R.K., T.J. O'Shea, and C.A. Beck. 1983. Manual of
procedures for the salvage and necropsy of carcasses of the
West Indian manatee (Trichechus manatus). Sirenia Project,
U.S. Fish and Wildlife Service, Gainesville, Fla.: v + 175.
(Available for sale from National Technical Information
Service, Springfield, Va. 22161; document no. PB83-255273.)
Buergelt, C.D., and R.K. Bonde. 1983. Toxoplasmic
meningoencephalitis in a West Indian manatee. J. Amer. Vet.
Med. Assoc. 183(11): 1294-1296.
Domning, D.P. 1983. Marching teeth of the manatee. Nat. Hist.
92(5): 8, 10-11. May 1983.
Eberhardt, L.L. 1982. Censusing manatees: A report on the
feasibility of using aerial surveys and mark and recapture
techniques to conduct a population survey of the West Indian
Manatee. Prepared for U.S. Fish & Wildlife Service by
Florida Coop. Fish & Wildlife Research Unit, Gainesville:
Manatee Population Research Report No. 1: 1-18.
Furusawa, H., and M. Kimura. 1982. Discovery of new species of
Sirenia from the Lower Pliocene in the Sorachi River,
Takikawa city, Hokkaido. J. Geol. Soc. Japan 88(10): 849-
852. [In Japanese. Discovery of a partial skeleton of
Hydrodamalis is reported, but no new species are actually
Gallivan, G.J., and R.C. Best. 1983. Temperature regulation in
the Amazonian manatee Trichechus inunguis. Physiol. Zool.
56 (2) : 255-262.
Irvine, A.B. 1983. Manatee metabolism and its influence on
distribution in Florida. Biol. Conserv. 25(4): 315-334.
Irvine, A.B., and M.D. Scott. 1984. Development and use of
marking techniques to study manatees in Florida. Fla. Sci.
Kimura, M., et al. 1983. Occurrences of Early-Middle Pleistocene
mammalian fossils from the Nopporo Hills in the Ishikari
Lowland, Hokkaido. Earth Sci. (Chikyu Kagaku) 37(3): 162-
177. [In Japanese; English summary. Reports a partial
skeleton of Hydrodamalis.]
Kinnaird, M.F. 1983. Aerial census of manatees and boats over the
lower St. Johns River and the Intracoastal Waterway in
northeastern Florida. Site-Specific Reduction of Manatee
Boat/Barge Mortality Research Report No. 2: iv + 56.
Kinnaird, M.F. 1983. Evaluation of potential management
strategies for the reduction of boat-related mortality of
manatees. Site-Specific Reduction of Manatee Boat/Barge
Mortality Research Report No. 3: ii + 43. [Includes
discussion of propeller guard designs, artificial barriers,
and acoustic repellents.]
Kinnaird, M.F. 1983. Site-specific analysis of factors
potentially influencing manatee boat/barge mortality. Site-
Specific Reduction of Manatee Boat/Barge Mortality Research
Report No. 4: iv + 41.
Kinnaird, M.F., and J. Valade. 1983. Manatee use of two power
plant effluents on the St. Johns River in Jacksonville,
Florida. Site-Specific Reduction of Manatee Boat/Barge
Mortality Research Report No. 1: iii + 63. [This and other
papers in this series available on request from Endangered
Species Field Office, U.S. Fish & Wildlife Service, 2747 Art
Museum Drive, Jacksonville, Fla. 32207.]
Kleinschmidt, A. 1982. Wissenswertes u"ber die Sa"ugerordnung
der Seeku"he (Sirenia) unter besonderer Beru"cksichtigung
der Stellerschen Riesenseekuh Rhytina gigas (Zimmermann, 1780)
sowie ihre hochgradige Anpassung an das Wasserleben im
Vergleich zu den Walen. Braunschw. Naturk. Schr. 1(3): 367-
Kleinschmidt, A. 1983. Notiz zu weiterem Skelet-Material der
Stellerschen Riesenseekuh Rhytina gigas (Sirenia, Mammalia).
Braunschw. Naturk. Schr. 1(4): 763-765.
Loveland, F.O. 1976. Tapirs and manatees: Cosmological categories
and social process among the Rama Indians of eastern
Nicaragua. In: M.W. Helms and F.O. Loveland (eds.), Frontier
Adaptations in Lower Central America. Philadelphia, Inst.
for Study of Human Issues: 67-82. [The Rama quite rightly
regard manatees as the embodiment of culture, society, and
Nishiwaki, M., et al. 1982. Recent survey on the distribution of
the African manatee. Sci. Rept. Whales Res. Inst. 34: 137-
Packard, J.M., R.C. Summers, and L.B. Barnes. 1983. Correction
factors for observability of manatees during aerial surveys.
Florida Coop. Fish & Wildlife Research Unit, Gainesville:
Tech. Report No. 8, Manatee Population Research Report No.
3: 1-10. [Available from Coop. Fish & Wildlife Research
Unit, 117 Newins-Ziegler Hall, Univ. of Florida,
Gainesville, Fla. 32611.]
Piggins, D., W.R.A. Muntz, and R.C. Best. 1983. Physical and
morphological aspects of the eye of the manatee Trichechus
inunguis Natterer 1883: (Sirenia: Mammalia). Mar. Behav.
Physiol. 9(2): 111-129.
Rathbun, G.B., J.A. Powell, and G. Cruz. 1983. Status of the West
Indian manatee in Honduras. Biol. Conserv. 26(4): 301-308.
Rich, V. 1983. Sea-cow relics for museum. Nature 306: 415. Dec.
1, 1983. [Reports discovery on Bering Island of "a virtually
complete skeleton" of Hydrodamalis, to be kept and displayed on
Bering Island itself.]
Shane, S.H. 1983. Manatees and power plants. Sea Frontiers
Shane, S.H. 1983. Abundance, distribution and movement of
manatees (Trichechus manatus) in Brevard County, Florida.
Bull. Mar. Sci. 33(1): 1-9.
Sprent, J.F.A. 1983. Ascaridoid nematodes of sirenians a new
species in the Senegal manatee. J. Helminth. 57: 69-76.
Steel, C. 1983. Vocalization patterns and corresponding behavior
of the West Indian manatee (Trichechus manatus). Dissert.
Abstrs. Internat. B. Sci. Eng. 43(10): 3160.
Takahashi, S. et al. 1983. Report on the excavation of the great
Yamagata sea cow. Yamagata Prefectural Museum, Special
Publ.: 1-76. [In Japanese. Concerns a new Late Miocene
species of Dusisiren, ancestral to Hydrodamalis, which will
be formally described elsewhere.]
Tiedemann, J.A. 1983. Observations of the West Indian manatee,
Trichechus manatus, in Turkey Creek, Brevard County,
Florida. Fla. Sci. 46(1): 1-8.
Wells, N.A., and P.D. Gingerich. 1983. Review of Eocene
Anthracobunidae (Mammalia, Proboscidea) with a new genus and
species, Jozaria palustris, from the Kuldana Formation of
Kohat (Pakistan). Contrib. Mus. Pal. Univ. Michigan 26(7):
117-139. [Proposes, probably incorrectly, that sirenians are
descended from anthracobunids.]
Werzinger, J. 1982. Sensation im Tiergarten Nu"rnberg: Die
Flaschen-Seekuh. Tier 22(11): 34-37.
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