2) 1 renews T
?wsletter of the iuCY/SSC
Sfrenia Specialist group
NUMBER 2 OCTOBER 1984
EDITORIAL: TO BREED OR NOT TO BREED?
Most readers of this newsletter are aware that several
aquaria (at Miami, Amsterdam, Nirnberg, and Beijing) have in
recent years successfully bred West Indian manatees in captivity.
The Miami Seaguarium has even been able to release two captive-
bred animals to a semi-wild environment (see news item in this
issue). However, another byproduct of this success which has
received much publicity over the last few months is a proposal to
place 50 or more wild manatees in captivity for breeding
purposes, with the eventual aim of restocking to offset mortality
in the wild (see below, abstract by Cardeilhac et al. and cited
articles by DiPerna and White).
All biologists applaud these breeding successes, and hope
that such efforts will continue. And if there develops a surplus
of captive-bred animals not needed for research or display, it is
certainly desirable for them to be released into the wild. The
suggestion at which biologists balk, however, is that large
numbers of manatees should be removed from already-depleted wild
populations for the purpose of captive breeding.
A variety of objections to such a project have been raised:
the danger of death or injury to animals during capture and
transport, the possibility of accidents during captivity (two
fatal accidents have already befallen the Miami Seaquarium's
captive-bred manatees), the potential dangers of inbreeding, the
UNION INTERNATIONAL POUR LA CONSERVATION OE LA NATURE ET OE SES RESOURCES
INTERNATIONAL UNION FOR CONSERVATiON OF NATURE AND NATURAL RESOURCES
Commission de la seuvegarde des espbes---Species Survival Commission
Sirenews Is edited by Daryl P. Domning, Dept. of
Anatomy, Howard University, Washington, D.C.
20059 USA. It Is supported by the Species Survival
Commission of IUCN, the U.S. Fish and Wildlife
Ssrvine. and the U.S. Marine Mammal Commission.
question of captive-bred animals' ability to adapt to the wild,
and the sheer cost of large-scale, labor-intensive captive
maintenance. Still worse is the danger that some people,
especially government officials with management responsibilities,
may come to view wild manatees as expendable if they think they
can be "replaced" easily from captive stock. Yet to my mind there
are even more fundamental flaws in the idea. I would ask: what
problem is such a program designed to solve, and what is the
philosophical basis (and hence the wider implications) of the
proposed solution? Only after answering these questions can we
intelligently judge the likelihood of success.
To put breeding animals in "protective custody" might be a
logical response to conditions which make breeding difficult or
impossible in the wild. But Florida manatees are breeding
perfectly well in the wild; faster, probably, than in captivity.
Aerial and ground surveys report healthy numbers of calves.
Florida manatees are threatened not by an insufficient birth rate
but by excessive mortality. The proper response, therefore, would
seem to be concentration of effort on reducing mortality, while
allowing the population to reproduce naturally. Moreover, there
is good evidence that natural winter mortality hits hardest the
weaned but immature animals, which apparently lack the experience
to find warm-water refugia in a timely manner. Captive-reared
manatees might be expected to fare even worse, both at this task
and at that of avoiding motorboats. If the environment is so
dangerous for adults that protective custody is called for, will
it not be equally dangerous for their newly released offspring? I
conclude that captive breeding to restock wild manatee
populations is a solution in search of a problem.
More bothersome still, in my opinion, is the philosophy that
invariably the best remedy for ill effects of human activity is
more human activity. When a species has become endangered through
man's meddling with its environment, it is safer and wiser to
back off as far as possible toward the natural situation, rather
than move toward a still more artificial one. We know that the
species can survive in its original environment; it has done so
for millions of years. But experience should have taught us that
the conditions we ourselves create are rarely stable, never
provide all the benefits advertised, and always have unpredicted
and unwelcome side effects. No well-informed species would choose
to depend on man's care, however conscientious and well-
intentioned. If we are honest we must admit that we lack the wit
to guarantee even our own survival, let alone that of other
Heroic attempts at captive propagation have been resorted to
with critically endangered species like whooping cranes and
golden lion marmosets, but it is too soon to tell whether these
efforts will succeed. Far better that manatees are never allowed
to decline to the point where such massive intervention is
needed. Responsible stewardship of nature must be based on the
principle of nature's right to autonomy: we are obligated to set
aside enough space and resources for wild populations to survive
on their own, without coming to us for handouts of food or
shelter. Aesthetics aside, we humans are neither wise enough nor
trustworthy enough to meet their needs for centuries or millenia
to come. Let us, in this area at least, put aside our
technologist mentality and stop tinkering. Let us respect
nature's ability to get along without us, and in so doing let us
learn a little humility. DPD
Having been among the earliest modern workers on the
Sirenia, we are specially glad to see the birth of Sirenews and
congratulate its editor, Daryl Domning. When we started study on
the Manatees in Guyana in 1962 and the Dugongs in Queensland in
1965, there was almost no knowledge about Sirenia (except of
their anatomy), nor workers on them and little known even of
local distribution let alone world distribution, growth or
breeding rates. The need for conservation measures everywhere for
them was little in the minds of scientists and not at all on the
conscience of the informed public.
Progress has, by the diligence particularly of workers in
Florida, Manaus and Queensland, been greatly encouraging. Yet
sadly it should be recognized that during this little more than a
score of years, probably the total of individual Seacows alive in
the world has diminished. Concurrently quite certainly the total
of our own species, their ultimate predators, has increased by
1000 million. That is the true measure of the need for
conservation effort world over.
As we ourselves retire through age from direct effort on
behalf of the Sirenia, we wish our friends and fellow workers
full vigout and success.
Kate Ricardo Bertram
[EDITOR'S COMMENT: Newcomers to sirenian research and
conservation may not realize how recent a phenomenon is the
worldwide interest and activity reflected in this newsletter.
Scarcely fifteen years have passed since Colin and Kate Bertram
were virtually the Qaily people on earth speaking out urgently and
consistently for the study and protection of sirenians. The fact
that so many hands have turned to this work in the ensuing years
is a tribute to the effectiveness of their pleas. Their voices in
the wilderness prepared the way for the present flowering of
sirenian biology, and they are the spiritual parents of all of us
who work in this field. We owe them our gratitude, and wish them
long life and happiness in their retirement.]
THE SIRENIA SPECIALIST GROUP AND ITS FUNCTION
The Sirenia Specialist Group should serve as a primary
source of the scientific and technical information required for
the conservation of the Sirenia, as well as recommending and
promoting measures for their conservation.
Within this context, we must gather, review systematically,
and assist in the dissemination of information on the status of
each sirenian species, and identify which are endangered or
vulnerable or are likely to become so.
We must ensure the accuracy of the species accounts in the
Red Data Book.
As necessary, we must identify the causes of actual or
potential threats to the survival of the species and devise ways
to obtain information needed.
We must prepare, or advise on the desirability and
practicality of, specific proposals for management that would
reduce or eliminate threats to species survival.
We must identify regions and ecosystems where there are
significant numbers of endangered species.
We must advise on controversial issues regarding the
management of species.
We must identify situations where international cooperation
is needed in the conservation of sirenians and other non-
domesticated fauna, and recommend the form of cooperation that
should be undertaken.
We must participate in the development of the World
Conservation Strategy, the programme of IUCN, and, as necessary,
in the development and screening of projects, and maintain a
roster of experts from which individuals or groups can be
selected to assist in those and other specific tasks.
We must facilitate communication within the professional
community concerned with the role of the Species Survival
Commission. Robin Best
Dr. Masaharu NISHIWAKI
14 April 1984,- in Tokyo, of a heart attack
at the age of 69.
Mass Stranding of Dugongs. On 23 March 1984, Cyclone Kathy
crossed the coast of the Gulf of Carpentaria in northern
Australia, severely damaging the isolated township of Borroloola,
wrecking several trawlers and killing one fisherman. The
accompanying storm surge swept across the vast complex of saline
coastal flats and mangrove-lined channels that compose the
McArthur River delta. The retreating water stranded hundreds of
large sea turtles, numerous large fish and rays and at least 27
The stranded animals were not observed until five days after
the cyclone. When officers of the Conservation Commission of the
Northern Territory established that most of the dugongs and sea
turtles were still alive, the Commission decided to mount a
three-day rescue operation. Many Borroloola residents postponed
their own post-cyclone cleanup to help. The Australian National
Parks and WIldlife Service funded the travel expenses of dugong
and turtle biologists so that they could offer specialist advice
and collect data from the stranded animals.
In the area affected by the storm surge, enormous tracts of
mangrove trees were bereft of leaves. The mudflats were very wet,
making walking extremely difficult, but were criss-crossed with
the tracks of hundreds of turtles going nowhere, and studded with
the carcasses of dead fish and huge rays.
Most dugongs were in wallows about 3 m in diameter,
containing water up to about 30 cm deep. Only the backs of these
animals were protruding. Even this region was kept moist as the
dugongs spun around their longitudinal axes occasionally. This is
the same behavior which renders dugongs particularly susceptible
to drowning in nets. We first thought that this wallow-making
behavior was amazingly adaptive, but it soon became obvious that
the wallows were the inevitable result of the animals' thrashing
around in the mud. Some dugongs had moved up to about 20 m across
the mudflats. Such movement seemed to be by rolling. We saw no
evidence of dugong flipper marks.
The only practicable means of reaching the animals was by
helicopter. The dugongs were very distressed by the engine noise
and reacted by frantically pounding their tails.
We located seven dugongs on the first day of the rescue, one
week after the cyclone. Five were in wallows; the other two were
in drier areas but covered in mud. We were amazed at how good
their condition was. There was little evidence of superficial
skin damage apart from some slight cracking, but the undersides,
especially of the larger animals, were extensively bruised. Large
"dugong tears" dribbled from the eyes of animals once they were
out of the water. Not surprisingly, some of the dugongs had
apparently lost weight; the outlines of the spinal processes of
two males were visible and the large females seemed to have lost
condition around the belly area.
Most of the dugongs thrashed about vigorously on approach
and were quite difficult to handle. At the suggestion of a local
fisherman, we tied a rope around each dugong's tailstock prior to
hauling it onto the helicopter cargo net, which we lined with a
tarpaulin in an attempt to prevent rope burns. Getting the
dugongs into the net was not easy, especially in the case of
large animals, and I ended up with a spectacular black eye caused
by a blow from the tail-fluke of one large female. Once cocooned
in the cargo net, each animal was lifted off with the helicopter,
carried to a nearby watercourse, lowered and released.
The first three dugongs were small (2 m long or less), and
stranded relatively close together. The operation to rescue and
release them took only 40 minutes. We then rescued a large (2.8
m) female and another young female. All swam off strongly and we
began to feel quite blas6.
The fourth animal was an adult male. He was very strong and
vigorous, and we were very wary of his tusks as he fought to stay
out of the cargo net. We finally managed to restrain him and he
was lifted to the bank of a nearby creek. We were shocked to
learn that he was dead on arrival.
A large female with long nipples and bulging vulval region
was next. She became quite frantic when approached, spinning
around and around, and whipping her tail. She quietened down in
the net after wriggling into a head-down position so that her
nostrils were covered for much of the five-minute journey. She
too was dead on arrival.
We necropsied both animals soon afterwards, racing against
the dusk. The male was fairly old, but not in breeding condition.
The female was very fat, pregnant with a 30 cm foetus, and
lactating: the first pregnant, lactating dugong I have seen.
Neither animal showed any evidence of injury or disease. In both
cases, the alimentary canal, including the stomach, was packed
with seagrasses. Apparently the digestive system had shut down
after the stranding. We collected a range of specimens for
The only other dugong necropsied was another lactating
female which we found dead eight days after the cyclone. She had
been dead for about two days. Again, there was no evidence of
injury or disease and the alimentary canal was packed with
By day two of the rescue operation, we had evolved quite an
efficient rescue technique. Once a dugong was located, the
"capture team" of four or five people was landed by the Jetranger
helicopter as close to the animal as possible. The "release team"
of three was then landed adjacent to the nearest suitable
watercourse. The "capture team" measured and sexed the animal,
and manhandled it onto the cargo net. We would then go and wait
away from the dugong for the helicopter to reappear. There seemed
to be a lot of waiting, and we found that the dugong would lie
much more quietly if we kept our distance. When the helicopter
returned, one of the team would hook the net up as the helicopter
hovered overhead, while I directed the pilot using hastily-
learned standard signals. We would then watch nervously as the
dugong was raised by the helicopter. Although the 2.8 m-square
cargo net was fine for juveniles, it was barely adequate for the
adults which ranged up to 2.9 m in length with an estimated
weight of nearly 400 kg. Two animals wriggled so much that they
nearly dropped out of the net. In one instance, I was so
horrified at the prospect of a dugong falling from 50 feet that I
put my hand over my mouth, much to the consternation of the
helicopter pilot who couldn't understand this new hand signal.
Amazingly, we had no more deaths. The "release team" found
it best for the dugongs to be lowered directly into the water by
the helicopter. On one occasion, they had to scare a crocodile
away before the dugong was lowered. Most dugongs swam off
strongly. One large female seemed disoriented and lay quietly for
a few minutes before swimming away. The two smallest animals,
calves just a few months old, swam around aimlessly as if looking
for their mothers. Their survival prospects seemed very slim.
We sighted a total of 27 stranded dugongs. Only two of these
were already dead. Twenty-three of the remainder were
successfully released over three days. By the end of the third
day the general condition of the dugongs had markedly
deteriorated. Their skin was cracking and peeling. Some animals
were almost moribund in the wallows, which were rapidly drying
up. I measured the water temperature in one wallow; it was 35
Centigrade at 11 A.M. Even if we had had the funds for another
day's helicopter time, I doubt that we would have found many
more dugongs alive. The total number of dugongs stranded by the
surge is unknown as we were unable to search the whole area. We
found dugongs scattered over about 200 square km and up to 8 km
from the sea. One large female was behind a clump of mangroves
about 3 m high.
Of the 25 stranded dugongs sexed, 12 were male. All but two
of these were juveniles, including one animal only a few months
old. I find it amazing that such a young dugong could survive for
more than a week without food. It is also interesting that the
only three dugongs that we heard calling were all young calves
who made soft bird-like chirping noises. Six of the stranded
females were also juveniles. Of the seven adult females examined,
three were probably both pregnant and lactating, while another
three were probably lactating. Thus it seems that a high
proportion of the animals stranded were mothers and calves.
One of the most rewarding aspects of the whole exercise was
that it provided the opportunity for people from very diverse
backgrounds to work together. Fishermen, native hunters, other
Borroloola residents, wildlife rangers and scientists, all
learned a great deal about each others' points of view. We also
gained valuable information about dugongs and sea turtles. -
- Helene Marsh
The First South American Workshop on Marine and Freshwater
Mammals, held in Buenos Aires in June and organized by Lic. Hugo
P. Castello, was well attended by aquatic mammal biologists from
Argentina, Brazil, Chile, Peru, and Uruguay as well as from non-
South American countries. In terms of manatees, the contribution
was completely Brazilian, and a total of four papers was
presented: on aging techniques using X-ray analysis of the
flipper, radio-tracking techniques, the physiological ecology of
the Amazonian manatee, and a survey of the population status of
and current research on manatees in Latin America. On the last
day of the meeting a round-table discussion was held to decide
research and conservation priorities for both manatees and otters
in South America. It is hoped that a proceedings volume will
result from this first meeting and that it will become a biennial
As for [the manatee project in] Manaus, we're bigger than we
were in the old days but the financial problems and instability
are taking their toll.... We have 20 manatees at present and no
funding whatsoever to do research. Our [support] for the CuruA-
Una [weed control and radio-tracking] project has run out and
there are no prospects of restarting it again. We have
applications with the Brazilian government for major financing of
the manatee .project which is starting to seem a bit more
positive, but nothing is guaranteed; also with WWF and OAS -
again the same picture. We are also waiting for some action from
the FAO/UNEP Global Plan of Action for Marine Mammals, but to
date nothing concrete has happened. It is quite disappointing to
be sitting on such potential [for] research and not be able to
Ironically, we are doing more dolphin than manatee work, as
we frequently receive accidentally-killed animals, and also
behavioral observations can be made within a few minutes' canoe
trip from Manaus. In between bouts of writing new proposals or
defending old ones, we are trying to get the osteological
collection completely documented and organized and to finish as
many of the unfinished projects in hand [as possible] so that if
we are forced to abandon ship we will not lose everything ...
Essentially our status is endangered whereas the manatee is
vulnerable Robin Best
[EDITOR'S COMMENT: Those responsible for funding and implementing
the FAO/UNEP Global Plan please take note of the above. The 73-
page compendium of Research Proposals for Sirznians, drawn up by
sirenian specialists a year ago under UNEP auspices, emphasized
(on pp. 7-8) the vital importance of maintaining the three
existing centers of sirenian research. If the Manaus project is
allowed to fold, we will lose one-third of the world's present
sirenian research capacity, as well as a facility with unique
research capabilities and opportunities and, incidentally, the
only one located in a Third World country. This is not the sort
of signal that conservation workers in the Third World need to
receive from international agencies. The time to do something
about it is NOW.]
Galen Rathbun reports the sad news that Butterball, the
Amazonian manatee long resident at the Steinhart Aquarium in San
Francisco, died on 22 September 1984 after just over 17 years in
captivity. Details of the circumstances of death are not
available at this writing, but postmortem examination is said to
have indicated lung and liver pathology.
In addition to entertaining and edifying a generation of
Steinhart visitors, Butterball provided data for at least four
scientific papers on veterinary care, karyotype, vocalizations,
and feeding behavior. In death, he may make his most valuable
contribution yet: he was by far the world's oldest tetracycline-
marked sirenian of known age. After his arrival at Steinhart in
1967, he was treated for a harpoon wound with tetracycline
antibiotics. Examination of his skeleton for tetracycline marks
should furnish data of great use in the effort to develop age-
determination techniques for manatees.
He will be missed.
The following items were contributed by the Gainesville lab:
1984 Manatee Mortality in Florida. A record high number of
winter season. Resightings compiled during the three years of the
catalog's operation provide information on the movements and site
fidelity of manatees in Florida.
Resightings of cataloged manatees in different years at the
same aggregation sites have documented site fidelity for 80
individuals. The greatest site fidelity has been demonstrated for
Riviera Beach, Fort Myers, Crystal River, and Blue Spring during
winter months and Brevard County during the summer. Nine manatees
are known to have used the same sites in four or more years, with
one individual, BC-09, resighted at Riviera Beach in six
different years. Thirteen manatees, however, changed winter
aggregation sites between winter seasons and three changed within
a single winter season. A total of 36 manatees have been
resighted at different aggregation sites, with the greatest
movements, in both number and distance, occurring on the east
coast. Movements have been documented between Jacksonville and
all major aggregation areas on the east coast except Miami. Three
individuals are known to have travelled nearly 600 km between
Jacksonville and Port Everglades over one-, two-, and three-year
periods, respectively, indicating that long-distance movements by
manatees are not uncommon. Seasonal north-south migrations have
been documented for eight individuals travelling from Riviera
Beach or Port Everglades to Brevard County, including one animal,
BC-09, known to have seasonally migrated from Riviera Beach to
Brevard County in four consecutive years. The only movement
documented along the west coast has been that of a manatee, TB-
22, known to have migrated from Tampa Bay to the mouth of the
Suwannee River between the winter and summer of 1983.
The technique of photographic documentation of scar patterns
to identify individuals has proved to be an effective tool for
long-term studies of manatees. The viability of the
identification catalog is demonstrated by BC-04, photographed
initially on 5 April 1978 and reidentified on 29 February 1984.
Future Plans. The Fish and Wildlife Service will be
reducing its manatee research effort due to cutbacks in funding.
A nine-month program of transferring carcass salvage activities,
including funding, coordination, and fieldwork, to the Florida
Department of Natural Resources will begin on 1 October 1984. The
Service will continue its research on manatee life history and
biology, which currently includes developing radio tracking
technology and gathering information on movement patterns,
distribution, reproduction, cow-calf relationships, and
Manatee Belease. The July/August 1984 issue of Marine
Mammal News reports that Dr. Jesse White of the Miami Seaquarium
has carried out the first release of manatees born and raised in
captivity. A male-female pair of two-year-old, 600-pound
manatees, named "Sunrise" and "Savannah", were released into the
Homosassa River on Florida's Gulf Coast in August. Dr. White, the
chief veterinarian at the Seaquarium, said that they will remain
in a two-acre area at Homosassa Springs Nature World for two
years, "while they master the eating and mating habits of their
wild cousins." They are part of a colony of seven manatees bred
dead manatees have been reported for the first eight months of
1984. One hundred and two animals have been recovered from the
southeastern United States: 100 from Florida, one from North
Carolina, and one from Puerto Rico.
The causes-of-death categories for January through August
1984 and the number of cases for each factor were: boat or barge
collision, 26; crushed or drowned in a floodgate or canal lock, 2
(one in floodgate, one in canal lock); dependent calf, 17;
natural, 25 (cold stress accounted for 20, and one each of
peritonitis, aborted fetus, old age, pneumonia, and mycotic
disease); and undetermined, 32 (mostly too decomposed for
Salvage Highlighta. Another pair of twin fetuses was
recovered from a salvaged carcass in June. A Blue Spring manatee
(Walter, BS-47, M-386) was found dead, from wounds inflicted by a
boat propeller, in the St. Johns River in May, adding another
tetracycline-marked animal to the collection. At least one animal
was butchered in May; however, the case is still in litigation
and the animal has not been included in the 1984 figures at this
time. Six animals have been rescued this year; however, only two
have survived and are undergoing rehabilitation in captivity.
Aerial Survevs. Bimonthly aerial surveys to assess the
distribution and movements of manatees in Lee County, Florida
were begun in December 1983. The manatee population in southwest
Florida, thought to be one of the largest in the state, is
receiving increased attention from U.S. Fish and Wildlife Service
researchers. A total of 819 manatee sightings have been made
through August 1984, averaging 45.5 manatees each survey
(SD=23.3). Counts ranged from 105 (5 January) to 19 (16 April).
Calves made up an average of 12.6% (SD=4.1) of the manatees seen
on each survey.
It was previously known that large numbers of manatees
gather in the Orange and Caloosahatchee Rivers during the winter
months, using the warm-water discharge of the Fort Myers Power
Plant as a thermal refuge. The ongoing aerial surveys indicate
that the Caloosahatchee River is used by manatees during warm
months to a greater extent than expected. Manatees have been
sighted in the Caloosahatchee on every survey, and on 13 of the
18 surveys more manatees were sighted in the rivers than in the
surrounding coastal areas. Of the coastal areas surveyed,
Matlacha Pass appears to show greater manatee use than Pine
Island Sound, San Carlos Bay, or Estero Bay.
Annual Updatfe th tMnatn. Identification Catalog. -
Photographs of distinctively scarred manatees taken during the
winter of 1983-84 have been used by the staff of the Sirenia
Project to update the statewide manatee identification catalog.
Seven of the nine areas covered by the catalog were visited (Blue
Spring, Jacksonville, Brevard County, Port Everglades, Miami,
Fort Myers, and Crystal River); Riviera Beach and Tampa Bay were
not covered. Ninety-eight manatees not previously identified have
been added to the catalog, which now includes 746 individuals.
Forty-one cataloged manatees were resighted during the 1983-84
at the Seaquarium. Dr. Paul Cardeilhac, a University of Florida
specialist in aquatic animal reproduction, is a medical
consultant in the program. One of his objectives is to speed up
the manatee's slow reproduction rate through captive breeding.
Manatee Ranae Extension. Gene Montgomery writes, under
date of 11 May 1984: "I learned last week of a manatee which has
been seen several times below the 1st lock [of the Panama Canal]
before the Pacific (Miraflores locks), thus manatee have entered
the eastern Pacificifl I have not had the time or resources to do
the survey necessary to know how many individuals have done so,
how far they have moved from the mouth of the canal, etc. I am in
the process of trying to find funding to support such a survey,
including the possibility of including such a survey in a new
study which would precede construction of a sea-level canal."
SIRENIA WORKSHOP ITC IV
(13-20 August 1985)
There was an encouraging response to the first circular
advertising this Workshop, with over 50 replies. The second
circular, which has been mailed to those who responded positively
to the first, calls for titles for poster presentations by 30
The Workshop will emphasize poster presentations because
they allow a larger number of presentations and greater
opportunity for one-to-one contact. Spoken presentations will be
limited to a keynote address by Daryl Domning and a series of six
invited review papers which will provide the background for a
Interested persons not on the mailing list and those with
queries should contact one of the convenors:
Helene Marsh Galen Rathbun and Tom O'Shea
Zoology Department U.S. Fish & Wildlife Service
James Cook University 412 N.E. 16th Ave.
Townsville 4811 Gainesville, Fla. 32601
Institute Nacional de Pesquisas da Amazinia
As noted above, I have been asked to address the sirenian
workshop at ITC IV. I have been giving some thought to what I
might say, and there is one subject I want to discuss on which I
would like some prior input from the sirenian research community.
Science is a process of seeking answers to questions, and
the science done will be no better than the quality of the
questions asked. I believe we are entering an era when the basic,
obvious questions about sirenians (distribution, status, gross
anatomy, reproductive and life history parameters, etc.) have
been or soon will have been answered. Will biologists then lose
what little interest in sirenians they now have, or will larger
and more interesting questions emerge to attract their attention?
To gauge the likelihood of the latter outcome, I am hereby
soliciting responses to the following question: WHAT DO YOU THINK
ARE THE MOST IMPORTANT UNANSWERED QUESTIONS THAT WE AS SCIENTISTS
CAN ASK ABOUT SIRENIANS? Suggest as many questions as you like.
No prizes will be awarded (and you need not be present to wint),
but I will summarize the results in a future issue. DPD
MARINE ANIMAL SYMPOSIUM
A Symposium on Endangered Marine Animals and Marine Parks
will be held at Cochin, South India from 12-16 January 1985. The
focal theme is conservation, management and habitat protection in
the form of reserves, national parks or sanctuaries for
endangered or vulnerable marine animals. The symposium will
review the present status of research and development efforts,
resources, conservation programs, future strategies, and national
policies in the Indian Ocean region. A call for papers has
already gone out and final manuscripts are due by 1 October 1984,
in order that the papers can be published at the time of the
symposium. For further details, contact The Convener, Symposium
on Endangered Marine Animals and Marine Parks, Marine Biological
Association of India, Post Box No. 1244, Ernakulam, Cochin-682
011, Kerala, India.
DUGONG VOLUME REPRINTED
The Du2gaoni Proceedings of a Seminar/Workshop held at James Cook
University 8-13 May 1979 (H. Marsh, ed.).
James Cook University has reprinted this volume in order to
meet a steady demand for copies. Copies can be ordered from: The
Bookshop, James Cook University of North Queensland, Townsville,
Qld. 4811, Australia. Cost: $10 Australian plus postage per copy.
Postage rates: Surface Airmail Aust.
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Information on the status of the West African manatee and
the dugong populations on the east coast of Africa is needed for
inclusion in the IUCN Mammal Red Data Book, Part 2 Africa.
Please send any relevant data to Jane Thornback, Compiler, Mammal
Red Data Book, IUCN Conservation Monitoring Centre, 219(c)
Huntingdon Road, Cambridge CB3 ODL, United Kingdom.
Hemopoiesis in the West Indian Manatee, Trichechus manatus
(M.D. Bazzini, J.E. Reynolds III, and R. Essman). West Indian
manatees (Trichechus manatus) and other members of the order
Sirenia, unlike most mammals, possess amedullary long bones.
Histological examinations of the visceral organs, sternum and
vertebral bodies showed that the primary site of hemopoiesis in
the manatee is the vertebral bodies. The vertebrae contained the
bone marrow and several diagnostic cell types including
megakaryocytes, erythroblasts and myelocytes. [From Florida
Scientist 47 (Suppl. 1), p. 19, 1984.]
Reproductive Potential of a Captive Breeding Colony at
Florida Manatees (P.T. Cardeilhac, J.R. White, and R. Francis-
Floyd). Recent interest in saving the manatee has encouraged
the ongoing program of captive breeding at the Miami Seaquarium.
This colony has ranged in size from two to nine manatees. Studies
were made on reproductive parameters of the colony in order to
project reproductive potential of a captive manatee colony.
Age at puberty was found not to occur before approximately
7.5 years based on colony history and serum progesterone
concentrations determined in two subadult females. The youngest
age at conception found for 2 animals was 7.5 years. The second
female became pregnant at approximately 8 years. A range for the
gestation period has been determined by establishing minimum and
maximum values. A minimum period (12 months) was determined by
establishing the beginning of pregnancy, using physical signs
confirmed by significant elevation in serum progesterone
concentration, followed by a date for the observed birth. A
maximum value for gestation period was the shortest determined
calving interval (14 months). A range for gestation period was
thus determined to be 13 (1) months.
The postpartum period of infertility for five captive births
ranged from 2 to 77 months with a mean value of 29 months.
Calving intervals for five captive births ranged from 15 to 91
months with a mean value of 42. Using these values, the average
adult female in this colony should produce 6 calves by thirty
years of age with an annual reproduction efficiency for females
of 0.2 (calves/year/female). Calf production would be about 120
per acre per year using high intensity production techniques as
practiced with this colony.
A sixty-fold increase in the size of the system used at
Miami Seaquarium would approximately replace the current annual
losses suffered by the wild population of manatees in Florida. A
10 to 20 fold increase in the size of the Seaquarium system would
probably insure that the manatee population of Florida remained
in positive reproductive balance, provided experimental release
of captive-produced animals is feasible. The experimental release
into the wild of 2 subadult manatees is planned for the summer of
1984. [From abstracts of the 15th Annual Conference and Workshop,
International Association for Aquatic Animal Medicine, Tampa,
Fla., Apr. 30-May 2, 1984.]
Aizu Fossil Research Group. 1982. On a fossil Sirenia [sic] from
the Shiotsubo Formation, Takasato, Yama, Fukushima
Prefecture, Northeast Japan. Earth Sci. (Chikyu Kagaku)
36(5): 282-284. [In Japanese. Report of Pusisiren cf. D.
jordani; Late Miocene.]
Anderson, P.K. 1984. Suckling in Dugong dugon. J. Mammal. 65(3):
Best, R.C. 1984. Trichechus inunguis vulgo peixe-boi. Ci4ncia
Hoje 2(10): 66-73.
Colmenero Rol6n, L.C. 1984. Nuevos registros del manati
(Trichechus manatus) en el Sureste de Mexico. An. Inst.
Biol. Univ. Nac. Autdn. Mexico (Ser. Zool.) 54(1): 243-254.
DiPerna, P. 1984. Manatee management: a question of freedom.
Calypso Log 11(3): 16-17. Sept. 1984.
Domning, D.P. 1984. Sea cow discovery. Nature 308(5959): 500.
Domning, D.P. 1984. Sea cows of the Chesapeake Bay. Bugeye Times
(Calvert Marine Museum, Solomons, Md.) 9(1): 5-6.
Domning, D.P., and L.-A. C. Hayek. 1984. Horizontal tooth
replacement in the Amazonian manatee (Trichechus inunglis).
Mammalia 48(1): 105-127.
Hall, A.J. 1984. Man and manatee: Can we live together? Nat.
Geogr. 166(3): 400-413. Sept. 1984. [Portfolio of underwater
Hudson, B.E.T. 1983. Dugongs of the northern Torres Strait,
Australia: Aerial surveys, observations during a tagging
project, catch statistics with recommendations for
conservation and management. Pacif. Sci. Congr. Proc. 15(1-
Hudson, B.E.T. 1984. So long, dugong. BBC Wildlife, June 1984:
298-301. [Popular account of the linkage between dugong
decline and cultural change among the Kiwai of Papua New
Jones, S. 1980. The dugong or the so-called mermaid, Dugong dugon
(Mdller) of the Indo-Sri Lanka waters problems of research
and conservation. Spolia Zeylanica 35 (I-II): 223-260. 6
Klein, E.H. 1979. Review of the status of manatee (Trich.ech.bsh
manatus) in Honduras, Central America. Ceiba 23(1): 21-28.
Lainson, R., R.D. Naiff, R.C. Best, and J.J. Shaw. 1983. Eimeria
trichechi n. sp. from the Amazonian manatee, Trichechus
inunguis (Mammalia: Sirenia). Syst. Parasitol. 5: 287-289.
Manzij, S.F., and O.Y. Piliptshuk. 1984. Morphologie und
Funktionsanalyse des Axialskeletes des amerikanischen
Lamantins Trichechus manatus Lin., 1758, Mammalia, Sirenia.
Zool. Jahrb. Anat. 111(3): 257-295. [English summary.]
Montgomery, G.G., N.B. Gale, and W.P. Murdoch, Jr. 1982. Have
manatee entered the eastern Pacific Ocean? Mammalia 46(2):
Packard, J.M., and J.D. Nichols. 1983. Sample size estimates: A
preliminary analysis of sample sizes required for mark-
recovery and mark-resighting studies of manatees (Trichechus
manatus) in Florida. Florida Coop. Fish & Wildlife Research
Unit, Gainesville: Tech. Report No. 8, Manatee Population /
Research Report No. 4: 1-14. [Available from Coop. Fish &
Wildlife Research Unit, 117 Newins-Ziegler Hall, Univ. of
Florida, Gainesville, Fla. 32611.]
Powell, J.A., and G.B. Rathbun. 1984. Distribution and abundance
of manatees along the northern coast of the Gulf of Mexico.
Northeast Gulf Science 7(1): 1-28.
Rathbun, G.B. 1984. Sirenians. Pp. 537-547 in: S. Anderson and
J.K. Jones, Jr. (eds.), Orders and Families of Recent
Mammals of the World. New York, John Wiley & Sons.
Sleeper, B. 1984. Manatee: North America's most unusual mammal
struggles for survival. Pacif. Discovery 37(1): 14-23.
Snipes, R.L. 1984. Anatomy of the cecum of the West Indian
manatee, Trichechus manatus (Mammalia, Sirenia).
Zoomorphology (Berlin) 104(2): 67-78.
Sokolov, V.E., and L.M. Mukhametov. 1982. [Electrophysiological
investigation on sleep in the manatee Trichechus manatus.)
Zh. Evol. Biokh. Fiziol. 18(2): 191-193. [In Russian;
Tisdell, C.A. 1983. Conserving living resources in Third World
countries: Economic and social issues. Int. J. Environ.
Stud. 22(1): 11-24. [Dugongs used as example.]
Villa-Ramirez, B., and L.C. Colmenero Roldn. 1981. Presencia y
distribucidn de los manaties o Tlacamichin Tricbhecbi
manatu Linneo 1782, en Mdxico. An. Inst. Univ. Nac. Autdn.
M6xico (Ser. Zool.) 51(1): 703-708.
White, J.R. 1984. Man can save the manatee. Nat. Geogr. 166(3):
414-418. Sept. 1984.
In the last issue, Kanwisher's name was inadvertently omitted
from the authorship of the following paper:
Gallivan, G.J., R.C. Best, and J.W. Kanwisher. 1983. Temperature
regulation in the Amazonian manatee Trichechus innguis.
Physiol. Zool. 56(2): 255-262.
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