Larger than their Atlantic walrus cousins, Pacific walruses can weigh up to 4,400 pounds (2,000 kilograms). Once hunted heavily, the biggest threat to walruses in recent times is climate change. As ocean habitats warm, receding sea ice is forcing the beasts to stay on land in overcrowded conditions.
Grist: Meet New York Aquarium’s adorable new rescued baby walrus
by Jess Zimmerman
Baby walrus calf Mitik was discovered, orphaned and ailing, off the coast of Alaska in July. Now he’s all grown up — he’s still a baby, but he weighs 234 pounds, which is pretty grown indeed — and he’s traveling all the way from Alaska to New York City, possibly with his head in his keeper’s lap the whole way.
Mitik won’t be on display in his new home at the New York Aquarium until spring, so until then, you’ll need to watch videos of him on YouTube. Back before Mitik had a name, we posted this one of him snuggling with an Alaska Sea Life Center worker.
The New York Aquarium already has two walruses, Kula and Nuka, but they’re such social creatures that it’s important they never be left alone. Since Nuka is getting up there in years, the aquarium is bringing in Mitik as a backup so Kula won’t be lonely if she dies. But it’s not just for Kula’s sake — they’re also taking Mitik because he’s an orphan who needs a home, and because he’s a super-cute chubby-wubby baby-woobly walrus-face…
California sea lions are champion deep-divers, withstanding descents more than 300 meters deep. Now, a female California sea lion fitted with a data logger (pictured) has yielded the sea lions’ secret, scientists report online today in Biology Letters.
For decades, zoologists had suspected that marine mammals such as seals and sea lions collapse their lungs to withstand water pressures and endure deep dives. So scientists used the data logger to keep track of the partial pressure of oxygen in the sea lion’s arterial bloodstream—a proxy to detect lung collapse—throughout her dives. During 48 dives in August 2011, each lasting an average of 6 minutes and reaching more than 300 meters deep, the sea lion’s lungs collapsed at about 225 meters down—and then re-expanded at the same depth during the mammal’s ascent.
This technique not only staved off decompression sickness, by keeping nitrogen out of the bloodstream, but also reduced the amount of oxygen delivered from her lungs to her bloodstream—preserving the oxygen within the sea lion’s upper airways. When she headed back to the surface, the preserved oxygen re-expanded into the lungs and prevented the sea lion from blacking out in the shallows. A trained, similarly outfitted California sea lion could help scientists gather even more data about this peculiar mechanism, the researchers suggest; we’ll have to hold our breath for that.
In the pinniped family, walruses are second in size only to elephant seals. Their flippers are flexible like hands, and each flipper has five digits.
They have a broad head, small eyes, and can be recognized by their tusks. (Both male and females walruses have tusks.)
Walrus use their tusks to fight, to defend against predators and to haul their massive bodies out of the ocean and on to ice. Those characteristic tusks, which are actually long teeth, can weigh up to 12 pounds (5 kg) each.
The walrus’ whiskers are not hairs, but actually extremely sensitive, tactile organs, much like a cat’s whiskers. The walrus uses these whiskers to seek out food along the seafloor…
The Hawaiian monk seal is listed as critically endangered by the IUCN. They can be found in the waters of the Papahānaumokuākea Marine National Monument (say that twice fast!). You can learn more about the Hawaiian and Mediterranean monk seals, as well as the extinct Caribbean monk seal, here… http://s.si.edu/dk3Oc.
“Bloody Hell! That’s the biggest leopard seal I’ve ever seen!”
Leopard seals are pretty scary predators, especially if you’re a penguin. But they can be friendly to other leopard seals, which is something that photographer Paul Nicklen learned during one of his trips to Antarctica.
He was taking underwater photos when a leopard seal started feeding him penguins, starting with live ones, which were released close to him (to see if he would catch them), and ending with half-chewed dead ones. One theory is that the leopard seal saw his reflection in the lens of the camera and thought that Nicklen was a fellow predator, but an awkward one in need of some help. This went on for FOUR DAYS…
The Ribbon Seal (Histriophoca fasciata) is one of nine species of ice seals inhabiting the Arctic. What sets them apart is that they are physiologically and anatomically adapted to make deeper dives and swim faster than other seals. Also making them unique, ribbon seals run across ice by alternating their foreflippers and swinging their hindquarters as opposed to using the caterpillar-like movement used by most other seals. Ribbon seal pups are born all white, but after one year they begin to develop the signature dark body with light bands.