Global Range: (Zero (no occurrences believed extant)) Historical range is not completely known, but it likely extended from the southern Gulf of Mexico to the Lesser Antilles, and north to southeastern Georgia and south to northern Panama and northern South America (east to Guyana) (see Adam 2004 for a fairly detailed map). Last reliable report of this species was from Serranilla Bank, Colombia, in 1952. Last reliable U.S. record was in 1922, when a seal was killed near Key West, Florida (see Adam 2004).
Monachus tropicalis has officially been declared extinct. Historically, the range of Caribbean monk seals was in the tropical waters of the Florida Keys, the Bahamas, the Greater and Lesser Antillies, around the Yucatan Penninsula, and around offshore islets and atolls. Currently, unconfirmed sightings are most common in Northern Haiti and North-east Jamaica. It is the only pinniped ever known to exist in the Caribbean region. The last recorded sighting of M. tropicalis in the United States was in 1932 off the coast of Texas and a small group was sighted on Seranilla Bank, between Honduras and Jamaica, in 1952.
Biogeographic Regions: nearctic (Native ); neotropical (Native ); atlantic ocean (Native )
Regularity: Regularly occurring
Type of Residency: Year-round
Caribbean monk seals were known to be beautiful animals. They had brown pelage, lightly frosted with gray, fading to a pale yellow on the stomach. They had hoodlike rolls of fat that surround their necks. Their hair was very short and stiff. The nails on the anterior digits were well developed, and nails on the posterior digits were simple. Their soles and palms were naked. They have also had 4, rather than 2 mammary glands. Their dental formula was 2/1, 1/1, 5/5. It is likely that there was sexual dimorphism, with males reaching up to 200 kg in some accounts. Females were likely smaller, ranging from 70-140 kg, although there is disparity in records. Infants were born with coal-black pelage.
Range mass: 70 to 200 kg.
Range length: 220 to 240 cm.
Average length: 222.50 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Length: 230 cm
Weight: 137000 grams
Differs from the California sea lion (escapes occur in monk seal range) in much shorter neck and limbs, hind limbs that cannot be turned forward or used effectively in terrestrial locomotion, and lack of ear pinnae. Differs from the hooded seal (errant juveniles of which have occurred in monk seal range) in lacking mottled pelage; hooded seal pelage is irregularly mottled black [or dark brown] and gray, though the distinctness of the mottling is reduced when the pelage is wet (looks dark gray) (Reeves and Ling 1981).
Little is known about the habitat of M. tropicalis. Likely, beach habitat was important, however they spent much of their time in the water. Caribbean monk seals occupied a marine environment, with rocky or sandy coastline for shelter and breeding areas. Unconfirmed sightings of M. tropicalis by divers usually take place underwater. This suggests they are rarely seen at the surface, or when they are, they are rarely recognized. Recent evidence indicates the ultimate contributing factor to the decline of Caribbean monk seals was loss of habitat.
Habitat Regions: temperate ; tropical ; saltwater or marine
Aquatic Biomes: reef ; coastal
Habitat and Ecology
Habitat Type: Marine
Comments: Shallow lagoons and reefs, sandy beaches, and permanent islets or beaches above high tide. Young were born on sandy beaches; undoubtedly required undisturbed sites.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Because Caribbean monk seals were classified as extinct before it was possible to study them, their primary diet is not known to science. It is assumed however, that it followed the typical monk seal diet of fishes and invertebrates. Caribbean monk seals are also assumed to have preyed on pelagic species, along with spiny lobsters, eels, octopus, and various other reef fish.
Animal Foods: fish; mollusks; aquatic crustaceans
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods, Molluscivore )
Comments: Probably ate mainly various fishes and shellfish.
The exact role this species played in the Caribbean ecosystem is unknown. As predators, they probably had some affect on regulating local fish populations.
Caribbean monk seals had relatively few predators. It is likely that the biggest threats to them (other than humans) were the sharks. Although they were agile swimmers, these seals were not able to move quickly while on land. Bbecause of their isolated evolutionary history, M. tropicalis was not equipped with an innate fear of predation on land. This made them relatively easy targets for pioneers and fishermen.
- sharks (Chondrichthyes)
- humans (Homo sapiens)
This list may not be complete but is based on published studies.
Known prey organisms
This list may not be complete but is based on published studies.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 0 (zero)
Comments: No confirmed sightings since 1952.
Zero, no individuals known extant
Comments: No extant populations or individuals known.
Life History and Behavior
Perception Channels: tactile ; chemical
Comments: Probably intermittently active day/night.
Actual lifespan of M. tropicalis is unknown. However it is believed the average life span was around 20 years.
Status: wild: 20 years.
The mating system of these seals is unknown.
Very little is known about the reproductive behavior of M. tropicalis. Births were likely in early December because several females killed in the Triangle Keys during this time had well-developed fetuses. One young per female is thought to have been born.
Breeding season: Births were likely to occur in early December.
Average number of offspring: 1.
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Little is known of the parental care of Caribbean monk seals. The nursing period is likely to have been relatively short, because the mother did not feed between birth and weaning. It is unknown what role, if any, male parental care played.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female)
Pupping season probably peaked in December.
It is believed that M. tropicalis is now extinct. Although there are unconfirmed sightings still in Caribbean areas, two expeditions in search of M. tropicalis failed to produce any evidence that M.tropicalis is still present in these waters.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: extinct
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1994Extinct(Groombridge 1994)
- 1990Extinct?(IUCN 1990)
- 1988Extinct?(IUCN Conservation Monitoring Centre 1988)
- 1986Extinct?(IUCN Conservation Monitoring Centre 1986)
- 1982Endangered(Thornback and Jenkins 1982)
National NatureServe Conservation Status
Rounded National Status Rank: NX - Presumed Extirpated
NatureServe Conservation Status
Rounded Global Status Rank: GX - Presumed Extinct
Reasons: Formerly ranged throughout the Caribbean Sea region; decimated by sealers in the 1800s; no confirmed sitings since 1952, despite extensive surveys; presumed extinct.
Other Considerations: Inherent tameness and defense of pups increased vulnerability to slaughter.
Degree of Threat: A : Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species
Comments: Major factor in its extermination was over-hunting, principally for its oil, during the 19th century. Disturbance of breeding areas by humans possibly played a role.
Global Protection: None. No occurrences appropriately protected and managed
Comments: No sites known for this species.
Needs: None, unless an extant population or individual is located.
Relevance to Humans and Ecosystems
It was believed that M. tropicalis was a competitor to the fishing industry. This belief inspired mass killings of M. tropicalis by fishermen.
Christopher Columbus was the first to note this species in his accounts. With the arrival of other Europeans, M. tropicalis was relentlessly exploited for the commercially valuable oil produced from their blubber. It was also used, less commonly, for meat.
Positive Impacts: food
Comments: When hauled out on land, evidently was not wary of humans; easily killed (e.g., for oil). Apparently was heavily hunted in breeding area at Arrecifes Triangulos, Bay of Campeche, in the mid-1800s (see Wing 1992).
IUCN Red List Category
Caribbean monk seal
The Caribbean monk seal, West Indian seal (Monachus tropicalis), or sea wolf, as early explorers referred to it, was a species of seal native to the Caribbean and now believed to be extinct. The Caribbean monk seals' main predators were sharks and humans. Overhunting of the seals for oil, and overfishing of their food sources, are the established reasons for the seals' extinction. The last confirmed sighting of the Caribbean Monk Seal was in 1952 at Serranilla Bank, between Jamaica and Nicaragua. In 2008 the species was officially declared extinct in the United States of America after an exhaustive search for the seals which lasted for about five years. This analysis was conducted by the National Oceanic and Atmospheric Administration and theNational Marine Fisheries Service. Caribbean Monk Seals were closely related to the Hawaiian monk seals (Monachus schauinslandi), which live around the Hawaiian Islands, and are critically endangered, and Mediterranean monk seals (Monachus monachus), which are also critically endangered. An estimated 600 Mediterranean monk seals and 1,100 Hawaiian monk seals are alive in the wild.
Caribbean monk seals had a relatively large, long, robust body, and has the capacity to grow up to nearly 2.4 metres (8 ft) in length and weighed 170 to 270 kilograms (375 to 600 lb). Males were probably slightly larger than females, which is similar to Mediterranean monk seals. Like other monk seals this species had a distinctive head and face. The head was rounded with an extended broad muzzle. The face had relatively large wide-spaced eyes, upward opening nostrils, and fairly big whisker pads with long light-colored and smooth whiskers. When compared to the body, the animal's foreflippers were relatively short with little claws and the hindflippers were slender. Their coloration was brownish and/or grayish, with the underside lighter than the dorsal area. Adults were darker than the more paler and yellowish younger seals. Caribbean monk seals were also known to have algae growing on their pelage, giving them a slightly greenish appearance, which is similar to Hawaiian monk seals.
Behavior and ecology
Historical records suggest that this species may have "hauled out" at sites (resting areas on land) in large social groups (typically 20-40 animals) of up to 100 individuals throughout its range. The groups may have been organized based on age and life stage differences. Their diet most likely consisted of fish and crustaceans.
Like other true seals, the Caribbean monk seal was sluggish on land. Its lack of fear for man and an unaggressive and curious nature also contributed to its demise.
Reproduction and longevity
Caribbean monk seals had a long pupping season, which is typical for pinnipeds living in subtropical and tropical habitats. In Mexico, breeding season peaked in early December. Like other monk seals, this species had four retractable nipples for suckling their young. Newborn pups were probably about 1 metre (3 ft 3 in) in length and weighed 16 to 18 kilograms (35 to 40 lb) and reportedly had a sleek, black lanugo coat when born. It is believed this animal's average lifespan was approximately twenty years.
Caribbean monk seals were found in warm temperate, subtropical and tropical waters of the Caribbean Sea, Gulf of Mexico, and the west Atlantic Ocean. They probably preferred to haul out at sites (low sandy beaches above high tide) on isolated and secluded atolls and islands, but occasionally would visit the mainland coasts and deeper waters offshore. This species may have fed in shallow lagoons and reefs.
The first historical mention of the Caribbean monk seal is recorded in the account of the second voyage of Christopher Columbus. In August of 1494 a ship laid anchor off the mostly barren island of Alta Velo, south of Hispaniola, the party of men went and killed eight seals (Sea Wolves) that were resting on the beach. The second recorded interaction with Caribbean monk seals was Juan Ponce de León’s discovery of the Dry Tortugas Islands. On June 21, 1513 Ponce de León discovered the islands, he ordered a foraging party to go ashore, where the men killed fourteen of the docile seals. There are several more records throughout the colonial period of seals being discovered and hunted at Guadelupe, the Alacrane Islands, the Bahamas, the Pedro Cays, and Cuba. As early as 1688 sugar plantations owners sent out hunting parties to kill hundreds of seals every night in order to obtain oil to lubricate the plantations machinery. A 1707 account describes fisherman slaughtering seals by the hundreds for oil to fuel their lamps. By 1850 so many seals had been killed that there were no longer sufficient numbers for them to be commercially hunted.
In the late nineteenth and early twentieth centuries scientific expeditions to the Caribbean encountered the Caribbean monk seal. In December 1886 the first recorded scientific expedition, to research seals, led by H. A. Ward and Professor F. Ferrari Perez as part of the Mexican Geographical and Exploring Survey, ventured to a small collection of reefs and a small cay known as the triangles (20.95° N 92.23° W) in search of Monachus tropicalis. Although the research expedition was in the area for only four days, forty-two specimens were killed and taken away; the two leaders of the expedition shared them. Two specimens from this encounter survive intact at the British Museum of Natural History and the Cambridge Zoological Museum respectively. The expedition also captured a newly born seal pup that died in captivity a week later.
The first Caribbean monk seal to live in captivity for an extended period was a female seal that lived in The New York Aquarium. The seal was captured in 1897 and died in 1903, living in captivity for a total of five and one-half years. In 1909 The New York Aquarium acquired four Caribbean monk seals, three of which were yearlings (between one and two years old), and the other a mature male.
The final extinction of the Caribbean monk seal was triggered by two main factors. The most visible factor, contributing to the Caribbean monk seals demise, was the nonstop hunting and killing, of the seals, in the eighteenth and nineteenth centuries to obtain the oil held within their blubber. The insatiable demand for seal products in the Caribbean encouraged hunters to slaughter the Caribbean monk seals by the hundreds. The Caribbean monk seals’ docile nature and lacking flight instinct in the presence of humans made it very easy for anyone who wanted to kill one to do so. The second factor was the over fishing of the reefs that sustained the Caribbean monk seal population, with no fish, or mollusks to feed on the seals that were not killed by hunters for oil died of starvation or simply did not reproduce as a result of an absence of food. Surprisingly little was done towards attempting to save the Caribbean monk seal; by the time it was placed on the endangered species list in 1967 it was likely already extinct.
Through the first half of the twentieth century, Caribbean monk seal sightings became much more rare. In 1908 a small group of seals was seen at the once bustling Tortugas Islands. Fishermen captured six seals in 1915, which were sent to Pensacola, Florida and eventually released. A seal was killed near Key West, Florida in March 1922. There were sightings of Caribbean monk seals on the Texas coast in 1926 and 1932. The last seal recorded to be killed by humans was killed on the Pedro Cays in 1939. Two more seals were seen on Drunken Mans Cay, just south of Kingston, Jamaica in November, 1949. In 1952 the Caribbean monk seal was confirmed sighted for the last time at Serranilla Bank, between Jamaica and Nicaragua.
Unconfirmed sightings of Caribbean monk seals by local fishermen and divers are relatively common in Haiti and Jamaica, but two recent scientific expeditions failed to find any sign of this animal. It is possible the mammal still exists, but some biologists strongly believe the sightings are of wandering hooded seals, which have been positively identified on archipelagos such as Puerto Rico and the Virgin Islands. On April 22, 2009, The History Channel aired an episode of Monster Quest, which hypothesized an unidentified sea creature videotaped in the Intracoastal Waterway of Florida's southeastern coast could possibly be the extinct Caribbean monk seal. No conclusive evidence has yet emerged in support of this contention, however, and opposing hypotheses asserted the creature was simply a misidentified West Indian manatee, common to the area.
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