The Caribbean monk seal is now considered extinct; none have been seen since the early 1950s. Forty-nine specimens were collected in December of 1886. J.A. Allen examined the skins of 17 of these animals, including adult males and females, immatures, and suckling pups in January of 1897, and this study represents the best description of the physical appearance of species available. Additionally, the original field notes taken during another 19th century collection were recently found and provide first hand accounts of the behavior of this species in the wild.
Adult coloration was brown with a grayish tinge above, due to the tips of the hairs being lighter. The color became lighter on the sides, and transitioned to yellowish white below. The end of the muzzle and lower lip, and the sides of the muzzle were yellowish white. Adult vibrissae were predominantly whitish and smooth with a few having darker bases, and still other short vibrissae were entirely dark. No difference was noted between the external coloration of males and females. Younger animals tended to be paler than adults, being more yellowish dorsally, with ochre tones ventrally, and a dusky central area at the end of the muzzle. Like Hawaiian monk seals, Caribbean monk seals were said to occasionally have green algae growing on the pelage. Females had four abdominal mammae
Newborn Caribbean monk seals had a long, soft, glossy black lanugo coat that persisted for an unknown period of time. The vibrissae of pups were uniformly dark.
Adult Caribbean monk seals reached at least 2.4 m in length, (females may have been slightly larger than males). Hawaiian monk seals of comparable length to the largest reported for Caribbean monk seals weigh 170-270 kg. Newborns were probably about 1 m and 16-18 kg.
The dental formula is: I 2/2, C 1/1, PC 5/5.
Can be Confused With
No other pinniped species regularly inhabits the former range of the Caribbean monk seal. Hooded, harbor, and less frequently, harp seals are known to stray occasionally as far south as the central east coast of Florida, near the edges of the Caribbean monk seal's former range. A monk seal could easily be distinguished from all of the above by following collection of features: their long unspotted and unbanded body, brownish dorsal and pale ventral coloration, broad flat head and muzzle, and smooth unbeaded vibrissae. California sea lions that have escaped from captivity have also been reported from the Gulf of Mexico, but as otariid seals differ form monk seals by the presence of external ear pinnae, long oar-like fore flippers, and long narrow head and dog-like muzzle. There are also differences in swimming and mobility on land.
This monk seal once inhabited most of the Caribbean Sea. One exception was the western and northern Gulf of Mexico, where historic records from Texas have been refuted, and prehistoric midden material was re-evaluated to have come from trading. In prehistoric times, the range of the Caribbean monk seal may have reached north to South Carolina. The last stronghold of the species was Serranilla Bank, about half way between Jamaica and Honduras, where the last reported sighting was in 1952.
Ecology and Behavior
Observations made in the field and from animals collected in the 19th Century provide evidence that pups were born from at least late fall to early winter. A long pupping season is known for both the congeneric Hawaiian and Mediterranean monk seals that also live in sub-tropical habitats, and it is reasonable to assume this was also the case for the Caribbean monk seal. The animals collected in December 1886 included newborn pups, and several females with term fetuses. Also, an animal described as recently weaned was encountered in the spring and a female with a large fetus was taken in July.
It can be inferred that the Caribbean monk seal was a social species, possibly in the manner of the Hawaiian monk seal in that the large number collected in 1886 were all taken from three small cays in three days. Furthermore, the collectors describe finding females with term fetuses hauled-out near one another, and in another case a pregnant female was hauled-out in the vicinity of a female suckling a pup. Hauled-out groups of 20-40 were observed and reference was made to groups of 100 or more in earlier times. An otherwise undescribed group of five animals hauled-out together included a large, scarred adult male. On another occasion, the collectors encountered a group whose composition and numbers were not given, but the seals were “huddled together.” Young Caribbean monk seals were also described to rest in pools of water, presumably for thermoregulation.
Several descriptions exist of the vocalizations of the Caribbean monk seal. A young animal briefly held in captivity was said to grunt like a pig, and bark, growl and snarl like a dog. In another account, seals that were approached by hunters were said to “bark in a hoarse, gurgling, death-rattle tone.”
Generally, the seals were described as having very few scars from fighting, although one large adult male was observed with gashes and scars like seams.
Feeding and Prey
There is no information on food and feeding habits. The specimens collected in 1886 all had stomachs that had fluid only or were empty. The assumption at the time was that the diet consisted of fish. Native fishermen of the area were asked what these seals ate and replied that they fed “as generally on molluscous animals as on fish, and that their teeth suffered much wear and tear in the work of breaking shells.” The scarred adult male described above, also had teeth “worn nearly to stumps.”
Threats and Status
Extensive searches for Caribbean monk seals have been conducted with no success. The last sightings were from Serranilla Bank in 1952, and the species is now presumed to be extinct.
Adam, P.J. and G.G. Garcia. 2003. New information on the natural history, distribution, and skull size of the extinct (?) West Indian monk seal, Monachus tropicalis. Marine Mammal Science 19(2):297-317.
Allen, J.A. 1887. The West Indian monk seal (Monachus tropicalis, Gray). Bulletin of the American Museum of Natural History 2(1):1-34.
Gilmartin, W.G. and J. Forcada. 2002. Monk seals Monachus monachus, M. tropicalis, and M. schauinslandi. pp. 756-759 in W.F. Perrin, B. Würsig and J.G.M. Thiewissen, eds. Encyclopedia of Marine Mammals. Academic Press.
Kenyon, K.W. 1981. Monk Seals - Monachus Flemming, 1822. pp. 195-220 in S.H. Ridgway and R. Harrison, eds. Handbook of marine mammals, Vol. 2: Seals. Academic Press.
Leboeuf, B.J., K.W. Kenyon and B. Villa-Ramirez. 1986. The Caribbean monk seal is extinct. Marine Mammal Science 2(1):70-72.
Timm, R.M., R. M. Salazar and A. Townsend Peterson. 1997. Historical distribution of the extinct tropical seal, Monachus tropicalis (Carnivora: Phocidae). Conservation Biology 11:549-551.