It’s smarter, more dangerous, and more musical, than you might think.
by Jeremy Berlin
On ice floes and rocky beaches in the far North Atlantic, cinnamon brown blobs pile up in living heaps. Some weigh more than a ton. Some are longer than ten feet. Each is a rumpled portrait of buckteeth and whiskers, deep scars and bloodshot eyes. They nap, burp, squabble, and bark—“something between the mooing of a cow and the deepest baying of a mastiff,” noted a 19th-century explorer.
Walruses may seem familiar from Beatles lyrics and Lewis Carroll verses, but most of us will never see a herd in the wild. And few photographers have documented this dangerous, musical, and socially sophisticated pinniped, a fin-footed kin to seals, sea lions, and sea elephants.“I used myself as bait,” says Paul Nicklen, who spent three weeks aiming his lens at Atlantic walruses with the help of Swedish diver Göran Ehlmé.
“I sat on the shore, and the walruses would come along. They’d get curious. But they have to hit you with their tusks to figure out what you are. And for a walrus to hit one of us can be lethal…”
… are year-round residents of the arctic oceans. Their huge bulk is an adaptation to the cold of the long arctic winter, lowering their surface area-to-volume ratio to keep more heat inside. Males can grow up to 12 feet (3.6 m) long and weigh an average of 2000 lbs (900 kg). They also wear a very thick skin - the skin itself can be up to 4 inches (10 cm) thick on parts of their body, and the blubber layer underneath an additional 6 inches (15 cm).
Their most familiar feature is, of course, their tusks; these can grow up to 3.3 feet (1 m) long. They’re used mainly for dominance and other social displays, and the strongest males with the largest tusks are usually at the head of a group. They may also use their tusks to break holes in the ice and to help pull themselves out of the water, but the long teeth aren’t used in feeding. Walruses eat crustaceans and invertebrates from the sea floor in the shallow areas just offshore.
They find their prey using their faceful of whiskers, called vibrissae. Each is exceptionally sensitive, and with them the walrus can distinguish food items as small as a tenth of an inch (3 mm). Walruses have two other interesting anatomical features: they have an air pouch in their throat that they can inflate to allow them to hang suspended vertically in the water to sleep; and they have the largest baculum (the bone in the penis) of any animal, both relative to body size and in absolute terms, at up to 25 inches (63 cm) long.
Zalophus wollebaeki is found only around the Galapagos Archipelago. It doesn’t go far out to sea, and instead remains within around 16 kilometres of the coast. It hunts in shallow waters for octopus, fish, and crustaceans. Females gather on the shore in colonies of around 30 individuals, along with a few males who compete for access to the females. Gestation lasts 11 months, although the implantation of the fertilised egg is probably delayed for the female to wean her current pup.
Although populations have recovered from hunting during the 19th century, Z. wollebaeki is now under threat from conflicts with humans. They are sometimes caught in fishing nets, especially juveniles, because of their curious nature. The El Niño event of 1997-98 severely affected this species, and many migrated away. A virus called seal lion pox is also responsible for a number of deaths.
Threats affectingZ. wollebaeki are monitored by The Charles Darwin Research Centre, and the Galapagos Marine Reserve has helped to protect this species since 1998.
Monachus schauinslandi is the only true seal to live in tropical waters all year round. It is usually found around uninhabited islands of the Hawaiian Archipelago. To cope with this, it have some adaptations to living in a warm climate. These include being active mainly at night, and spending the day hauled out on beaches. It feeds on a variety of different prey items, such as fish, eels, and octopus.
Numbers of M. schauinslandi have been declining for a long time, and it was hunted intensively during the 1800s. Pollution causes the seals to become entangled in fishing nets, and a lack of food are believed to be the main threats to this species.
M. schauinslandi has been protected under the United States Endangered Species List since 1976. It is also monitored by the National Marine Fisheries Service, which surveys breeding colonies to find out the size of the population. In 2000, the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve was created to try to protect this species further.
Marine mammals are charismatic and iconic animals, particularly in the Arctic region, where the U.S. Fish and Wildlife Service leads cooperative programs for wildlife conservation in partnership with Russia’s Ministry of Natural Resources and Environment.
The bilateral cooperation between the U.S. and Russia supports a wide range of animals from native waterfowl to shared marine life. Marine mammals, particularly polar bears, walrus, and sea otters, are a major focus of this cooperation, conducted through the Wildlife Without Borders - Russia program, and the Service’s Alaska Marine Mammals Management Office.
Note: U.S.-Russia cooperation in the management of polar bears is conducted under a separate mechanism. For more information visit the Alaska Marine
The Hawaiian monk seal, known as “Ilioholoikauaua” or “dog that runs in rough water”, is found primarily on the Northwestern Hawaiian Islands. They’re one of the most endangered marine mammals on the earth today, with fewer than 1,300 left. Their populations are declining at a rate of 4% a year. Living on the remote Northwestern Hawaiian Islands, they spend most of their time in coral reefs foraging for lobster, fish and octopus.
Today, these precious creatures are dying of starvation and many are sick, injured and orphaned. They’re threatened by fishing gear, disease and shark predation. But global warming is the biggest harm to Hawaiian monk seals; sea levels are rising and erosion on Hawaii’s Northwest Islands is making their habitat vulnerable.
In the next five years, it’s estimated their population will plummet to less than 1,000. Stand with organizations like The Hawaiian-Environmental Alliance in urging the U.S. government to protect the Hawaiian monk seal from extinction…
Phylum : Chordata Class : Mammalia Order : Carnivora Superfamily : Pinnipedia Family : Desmatophocidae Genus : Allodesmus Species : A. courseni, A. gracilis, A. kelloggi, A. kernensis, A. megallos, A. packardi, A. sadoensis
Miocene (15 - 10 Ma)
2,4 m long and 360 kg
Allodesmus is an extinct genus of pinniped (group containing seals, sea lions, and walruses) from the Miocene and related to the genus Desmatophoca. It measured about 2.4 m long and weighed 360 kg. Allodesmus had the specific anatomical features found in modern polygynous pinnipeds: sexual dimorphism, strong canines for fights between bulls and teeth with well-defined growth zones, a result from periodic fasting (in order to defend their harem, males would not take to the sea to feed during the breeding season).
NMFS Denies Ribbon Seal Endangered Species Listing
The federal government has rejected an endangered species listing for a seal species that relies on sea ice for molting and reproducing.
The National Marine Fisheries Service announced Tuesday that it has rejected listing ribbon seals as a threatened or endangered species despite evidence that its habitat is impacted by climate change.
Ribbon seals are found in the Bering and Chukchi (Chuk-CHEE’) seas off Alaska and in the Sea of Okhotsk (oh-KOTSK’) off Russia. They are not in danger of disappearing under the time limits required for listing in the Endangered Species Act, a spokeswoman for the National Oceanic and Atmospheric Administration said.
"NOAA’s status review concluded that the anticipated threats to ribbon seals, primarily from reductions in sea ice and disrupted prey communities, will result in a gradual decline in ribbon seal population abundance," said Julie Speegle in the announcement. “However, this decline is not expected to render the species in danger of extinction within the foreseeable future."…