Caribbean monk seal
|Caribbean monk seal|
|Specimen in the New York Aquarium, ca. 1910|
The Caribbean monk seal, West Indian seal or sea wolf (as early explorers referred to it), Neomonachus tropicalis, was a species of seal native to the Caribbean and is 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 1994 the species was officially declared extinct in the United States 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 the National Marine Fisheries Service. Caribbean monk seals were closely related to the Hawaiian monk seals, which live around the Hawaiian Islands and are now endangered, and Mediterranean monk seals, another endangered species. 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, could grow 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 organised 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 of humans 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 western 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.
Relationship with humans
The first historical mention of the Caribbean monk seal is recorded in the account of the second voyage of Christopher Columbus. In August 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.
Through the first half of the twentieth century, Caribbean monk seal sightings became much rarer. 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.
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 lack of 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 overfishing 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 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.
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, and opposing hypotheses asserted the creature was simply a misidentified West Indian manatee, common to the area.
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- ADW: Monachus tropicalis
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