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New records of the West Indian manatee (Trichechus manatus) from the Bahama Islands
NEW RECORDS (TRICHECHUS
OF THE WEST INDIAN MANATEE MANATUS) FROM THE BAHAMA ISLANDS
DANIEL K. ODELL, JOHN E. 'REYNOLDS & GREGG WAUGH
Division of Biology and Living Resources, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA
ABSTRACT
The first positive sighting of a manatee (Trichechus manatus) in the Bahama Islands in more than 70 years was made on 12 September 1975 at West End, Grand Bahama Island. The only previous record was from the Bimini Island group in 1904. A dead manatee was found near Freeport, Grand Bahama Island, in November 1975. The skull, which was preserved, had a condylobasal length of 36.8 cm. Speculation concerning the origin of these animals is offered." a local population; immigration from Florida or other islands in the Bahamas; and importation by man. The manatee population in the Bahamas might be limited by freshwater sources. An aerial survey should be conducted to assess the manatee population, if any, in the Bahama Islands.
INTRODUCTION
The West Indian manatee (Trichechus manatus) is generally distributed throughout the Caribbean region from the southeastern United States (particularly Florida) to the northeastern coast of South America (Brazil) (Allen, 1942; Husar, 1977). It occurs in marine, estuarine, and freshwater habitats, and travels between the salinity extremes. This species of manatee is listed as 'endangered' by the United States Government (Anon., 1975). The other two species of manatee (T. inunguis, the Amazonian manatee; and T. senegalensis, the West African manatee), as well as T. manatus, have apparently been severely reduced in numbers by human activities. The exact status and current distribution of the populations of each species are unknown. The purpose of this paper is to document several recent sightings of the manatee in the Bahama Islands. The only published record of a manatee in the Bahamas is from Allen (1942, 538). He stated, 'Among the Bahamas there is almost no information of 289 Biol. Conserv. (14) (1978)--© Applied Science Publishers Ltd, England, 1978 Printed in Great Britain
290
DANIEL K. ODELL, JOHN E. REYNOLDS, GREGG WAUGH
its status at the present time, but in 1904 1 had a report of one killed in the Bimini islands on the western edge of the group. Of course, it may have come over from Florida.' (See Fig. 1.)
OBSERVATIONS We travelled to West End, Grand Bahama Island (approximately 26 ° 41'N Lat.; 70 ° 0 0 ' W Long., see Fig. 1) on 12 September 1975 to examine a 'monster' that had taken up residence in a boat-turning basin adjacent to a golf course belonging to the Grand Bahama Hotel. Upon our arrival at the turning basin, the 'monster', quite obviously a manatee, presented itself for inspection (Fig. 2). We estimated the animal to be about 2.7-3.0m long. We were unable to determine the sex of the animal as it was quite shy and would disappear beneath the turbid water when we approached.It seemed to be covered with a light yellowish material that may have been diatoms, suggesting that it had been in seawater for some time. Manatees
Fig. 1.
Map indicating the geographic relationsliip between the Bahama Islands, Florida, and the northern Caribbean islands. 1 = Bimini Islands. 2 = West End, Grand Bahama Island.
291
MANATEES 1N THE BAHAMAS
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DANIEL K. ODELL, JOHN E. REYNOLDS, GREGG W A U G H
observed along the Florida coast are usually dark grey in colour and commonly have barnacles. We saw none on this animal. The animal apparently moved in and out of the basin with the tide, being found there only at high tide. We were unable to locate the animal in the canal connecting the basin to the sea and suspected that it may have gone out to feed. There was no vegetation growing on the bottom of the basin or the canal. On a cursory examination ofshaUow waters near shore we observed vast beds of turtlegrass (Thalassia sp.), a known food of the manatee (Hartman, 1971). We were also unable to determine exactly, when the manatee arrived at West End or when it departed. It was apparently in the area for one to two months. However, the uniqueness of a manatee here was reflected in the curiosity of the local populace. The publicity that the event received in south Florida newspapers resulted in our learning of several probable manatee sightings in the same basin in 1965 (A. A. Horne, pers. comm., 1975). Dr Howard W. Campbell has also heard of probable manatee sightings in the Bahamas (pers. comm., 1975). The most important additional observations were provided by Mr Dennis Williams, an aircraft pilot from Freeport, Grand Bahama. He reported (pers. comms., 1976, 1977) that since 1973 he and other pilots had seen two manatees in the Grand Lucayan Waterway (a man-made canal near Freeport, on the south coast of Grand Bahama Island, about 30 km east o f West end approximately 26 ° 30' N lat.; 78 ° 47' W Long.). Apparently one of these animals disappeared some time before the manatee appeared at West End, and it is possible that they were the same animal. Most interestingly, a freshly dead manatee was found near Freeport in November 1975. No data were taken from this animal but it apparently did not show any external signs of having been hit by a power boat (i.e., propeller wounds). The skull was saved as a souvenir (D. Willi~/ms, pers. comm., 1976) and we were fortunate in being able to photograph and measure it. The condylobasal length is j36.8 cm and the maximum width across the zygomatic processes o f the temporal bone is 22.4 cm.
DISCUSSION
Considering the area encompassed by the Bahama Banks and their proximity to other Caribbean islands and to Florida where manatees are known to occur (Fig. 1 ; Husar, 1977), one is tempted to speculate about the possible existence of a manatee population in the Bahamas. Our records and those of 1904 are geographically close to the manatee population on the east coast of Florida. Allen (1942) suggested that the Bimini manatee may have come from Florida. If these manatees did come from Florida, it was necessary for them to cross the northward-flowing Gulf Stream. The starting points would probably have been at some point south of the final destinations to 'compensate' for the northward current. Nothing is known about the manatee's endurance in the open ocean. Such crossings, if they actually occur, are probably random events and one wonders how many manatees have missed the
MANATEES IN THE BAHAMAS
293
Bahamas and disappeared northward. Hamilton (1839, 290) gives two apparent records of manatees in northern European waters. A carcass was found at Newhaven, Firth of Forth, in the autumn of 1785. He also cites Duhamel (1782 ?), who apparently reported a female and calf manatee near Dieppe in northern France. Another possibility is that these manatees had moved northward from the more southerly islands in the Bahamas. If so, manatees might be scattered throughout the islands. The turtlegrass beds observed at West End are indicative of the general condition throughout the Bahamas, and the area would thus appear to be ideal for manatees. Hartmann (1974) speculated that the manatee population in Florida may be restricted by access to freshwater for drinking. Manatees move between fresh and salt water and they have been observed apparently drinking from freshwater hoses under several sets of circumstances. However, it is not known if manatees need to drink freshwater to maintain osmotic balance. Limited freshwater sources in the Bahamas could restrict the distribution and size of the manatee population. Finally, the possibility that the manatees that we observed had been transported from Florida by man cannot be eliminated. A thorough aerial survey of the Bahamas is needed to document the distribution and abundance of this species, and to determine if there is, indeed, a resident population.
ACKNOWLEDGEMENTS
Mr Sonny Waugh provided transportation from Florida to West End and the Grand Bahama Hotel provided lodging during our stay. Mr Rob Keith and Mr Dennis Williams brought the skull to our attention. Dr Clayton E. Ray, Smithsonian Institution, provided several helpful comments on the draft of this paper.
REFERENCES
ALLEN,G. M. (1942). Extinet and vanishing mammals of the western hemisphere with the marine species ~[' all the oceans. New York, Cooper Square. ANONYMOUS(1975). Endangered and threatened wildlife and plants. US Department o/the Interior, Fish and WildliJe Serviee, Federal Register, 30, 44412 29. DUHAMELDU MONCEAU,M. (1782). Des poissons CetaeOes, & des amphibibs. Traitb gbnOral des p&'hes et histoire des poissons, ou des animaux qui vivent dans I'eau. Suite de la seconde partie, 4(10), 1-73. Paris. HARTMAN, D. S. ( 197 I). Behaviour and eeology o[the Florida manatee, Trichechus manatus latirostris (Harlan), at Crystal River, Citrus County. Ph.D. thesis, Cornell University. HARTMAN, D. S. (1974). Distribution, status and conservation oJ the manatee in the United States. National Fish and Wildlife Laboratory, Gainesville, Florida. Unpublished manuscript. HUSAR, S. (1977). The West Indian manatee ( Triehechus manatas). US Department o/the Interior, Fish and WildliJe Serviee, WildliJe Research Report, 7, 22 pp. Washington, DC. HAMILTON, R. (1839). Amphibious carnivora, including the walrus and seals, also oj the herbivorous cetaeea, etc. The Naturalist's Library, mammalia, 8. Edinburgh, W. H. Lizars.
OF THE WEST INDIAN MANATEE MANATUS) FROM THE BAHAMA ISLANDS
DANIEL K. ODELL, JOHN E. 'REYNOLDS & GREGG WAUGH
Division of Biology and Living Resources, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA
ABSTRACT
The first positive sighting of a manatee (Trichechus manatus) in the Bahama Islands in more than 70 years was made on 12 September 1975 at West End, Grand Bahama Island. The only previous record was from the Bimini Island group in 1904. A dead manatee was found near Freeport, Grand Bahama Island, in November 1975. The skull, which was preserved, had a condylobasal length of 36.8 cm. Speculation concerning the origin of these animals is offered." a local population; immigration from Florida or other islands in the Bahamas; and importation by man. The manatee population in the Bahamas might be limited by freshwater sources. An aerial survey should be conducted to assess the manatee population, if any, in the Bahama Islands.
INTRODUCTION
The West Indian manatee (Trichechus manatus) is generally distributed throughout the Caribbean region from the southeastern United States (particularly Florida) to the northeastern coast of South America (Brazil) (Allen, 1942; Husar, 1977). It occurs in marine, estuarine, and freshwater habitats, and travels between the salinity extremes. This species of manatee is listed as 'endangered' by the United States Government (Anon., 1975). The other two species of manatee (T. inunguis, the Amazonian manatee; and T. senegalensis, the West African manatee), as well as T. manatus, have apparently been severely reduced in numbers by human activities. The exact status and current distribution of the populations of each species are unknown. The purpose of this paper is to document several recent sightings of the manatee in the Bahama Islands. The only published record of a manatee in the Bahamas is from Allen (1942, 538). He stated, 'Among the Bahamas there is almost no information of 289 Biol. Conserv. (14) (1978)--© Applied Science Publishers Ltd, England, 1978 Printed in Great Britain
290
DANIEL K. ODELL, JOHN E. REYNOLDS, GREGG WAUGH
its status at the present time, but in 1904 1 had a report of one killed in the Bimini islands on the western edge of the group. Of course, it may have come over from Florida.' (See Fig. 1.)
OBSERVATIONS We travelled to West End, Grand Bahama Island (approximately 26 ° 41'N Lat.; 70 ° 0 0 ' W Long., see Fig. 1) on 12 September 1975 to examine a 'monster' that had taken up residence in a boat-turning basin adjacent to a golf course belonging to the Grand Bahama Hotel. Upon our arrival at the turning basin, the 'monster', quite obviously a manatee, presented itself for inspection (Fig. 2). We estimated the animal to be about 2.7-3.0m long. We were unable to determine the sex of the animal as it was quite shy and would disappear beneath the turbid water when we approached.It seemed to be covered with a light yellowish material that may have been diatoms, suggesting that it had been in seawater for some time. Manatees
Fig. 1.
Map indicating the geographic relationsliip between the Bahama Islands, Florida, and the northern Caribbean islands. 1 = Bimini Islands. 2 = West End, Grand Bahama Island.
291
MANATEES 1N THE BAHAMAS
O
O
8
o O o~
b-
¢.q
o~
o O
0a O
c-i
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292
DANIEL K. ODELL, JOHN E. REYNOLDS, GREGG W A U G H
observed along the Florida coast are usually dark grey in colour and commonly have barnacles. We saw none on this animal. The animal apparently moved in and out of the basin with the tide, being found there only at high tide. We were unable to locate the animal in the canal connecting the basin to the sea and suspected that it may have gone out to feed. There was no vegetation growing on the bottom of the basin or the canal. On a cursory examination ofshaUow waters near shore we observed vast beds of turtlegrass (Thalassia sp.), a known food of the manatee (Hartman, 1971). We were also unable to determine exactly, when the manatee arrived at West End or when it departed. It was apparently in the area for one to two months. However, the uniqueness of a manatee here was reflected in the curiosity of the local populace. The publicity that the event received in south Florida newspapers resulted in our learning of several probable manatee sightings in the same basin in 1965 (A. A. Horne, pers. comm., 1975). Dr Howard W. Campbell has also heard of probable manatee sightings in the Bahamas (pers. comm., 1975). The most important additional observations were provided by Mr Dennis Williams, an aircraft pilot from Freeport, Grand Bahama. He reported (pers. comms., 1976, 1977) that since 1973 he and other pilots had seen two manatees in the Grand Lucayan Waterway (a man-made canal near Freeport, on the south coast of Grand Bahama Island, about 30 km east o f West end approximately 26 ° 30' N lat.; 78 ° 47' W Long.). Apparently one of these animals disappeared some time before the manatee appeared at West End, and it is possible that they were the same animal. Most interestingly, a freshly dead manatee was found near Freeport in November 1975. No data were taken from this animal but it apparently did not show any external signs of having been hit by a power boat (i.e., propeller wounds). The skull was saved as a souvenir (D. Willi~/ms, pers. comm., 1976) and we were fortunate in being able to photograph and measure it. The condylobasal length is j36.8 cm and the maximum width across the zygomatic processes o f the temporal bone is 22.4 cm.
DISCUSSION
Considering the area encompassed by the Bahama Banks and their proximity to other Caribbean islands and to Florida where manatees are known to occur (Fig. 1 ; Husar, 1977), one is tempted to speculate about the possible existence of a manatee population in the Bahamas. Our records and those of 1904 are geographically close to the manatee population on the east coast of Florida. Allen (1942) suggested that the Bimini manatee may have come from Florida. If these manatees did come from Florida, it was necessary for them to cross the northward-flowing Gulf Stream. The starting points would probably have been at some point south of the final destinations to 'compensate' for the northward current. Nothing is known about the manatee's endurance in the open ocean. Such crossings, if they actually occur, are probably random events and one wonders how many manatees have missed the
MANATEES IN THE BAHAMAS
293
Bahamas and disappeared northward. Hamilton (1839, 290) gives two apparent records of manatees in northern European waters. A carcass was found at Newhaven, Firth of Forth, in the autumn of 1785. He also cites Duhamel (1782 ?), who apparently reported a female and calf manatee near Dieppe in northern France. Another possibility is that these manatees had moved northward from the more southerly islands in the Bahamas. If so, manatees might be scattered throughout the islands. The turtlegrass beds observed at West End are indicative of the general condition throughout the Bahamas, and the area would thus appear to be ideal for manatees. Hartmann (1974) speculated that the manatee population in Florida may be restricted by access to freshwater for drinking. Manatees move between fresh and salt water and they have been observed apparently drinking from freshwater hoses under several sets of circumstances. However, it is not known if manatees need to drink freshwater to maintain osmotic balance. Limited freshwater sources in the Bahamas could restrict the distribution and size of the manatee population. Finally, the possibility that the manatees that we observed had been transported from Florida by man cannot be eliminated. A thorough aerial survey of the Bahamas is needed to document the distribution and abundance of this species, and to determine if there is, indeed, a resident population.
ACKNOWLEDGEMENTS
Mr Sonny Waugh provided transportation from Florida to West End and the Grand Bahama Hotel provided lodging during our stay. Mr Rob Keith and Mr Dennis Williams brought the skull to our attention. Dr Clayton E. Ray, Smithsonian Institution, provided several helpful comments on the draft of this paper.
REFERENCES
ALLEN,G. M. (1942). Extinet and vanishing mammals of the western hemisphere with the marine species ~[' all the oceans. New York, Cooper Square. ANONYMOUS(1975). Endangered and threatened wildlife and plants. US Department o/the Interior, Fish and WildliJe Serviee, Federal Register, 30, 44412 29. DUHAMELDU MONCEAU,M. (1782). Des poissons CetaeOes, & des amphibibs. Traitb gbnOral des p&'hes et histoire des poissons, ou des animaux qui vivent dans I'eau. Suite de la seconde partie, 4(10), 1-73. Paris. HARTMAN, D. S. ( 197 I). Behaviour and eeology o[the Florida manatee, Trichechus manatus latirostris (Harlan), at Crystal River, Citrus County. Ph.D. thesis, Cornell University. HARTMAN, D. S. (1974). Distribution, status and conservation oJ the manatee in the United States. National Fish and Wildlife Laboratory, Gainesville, Florida. Unpublished manuscript. HUSAR, S. (1977). The West Indian manatee ( Triehechus manatas). US Department o/the Interior, Fish and WildliJe Serviee, WildliJe Research Report, 7, 22 pp. Washington, DC. HAMILTON, R. (1839). Amphibious carnivora, including the walrus and seals, also oj the herbivorous cetaeea, etc. The Naturalist's Library, mammalia, 8. Edinburgh, W. H. Lizars.