From the category archives:

Marine Mammals

Guadalupe Fur Seal (Arctocephalus townsendi)

by JR Kinyak on May 7, 2009

in Marine Mammals

Guadalupe fur seal (click image to enlarge)

Guadalupe fur seal (click image to enlarge)


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Between yesterday’s squirrel and this seal today, I’m thinking about just going ahead and declaring this Interesting Ears Week.

The Guadalupe fur seal, as a species, has a dramatic story, full of hope and heartbreak. Once numerous from the Revillagigedo Islands of Mexico to the Farallones off of San Francisco, the seals were hunted so relentlessly in the 19th century that they were thought to be extinct from 1895 to 1926. Then, some fishermen “discovered” a group of them on Guadalupe Island, off Baja California. What did these fishermen do with these invaluable seals, thought lost forever? Why, killed them, of course.

Everyone thought they were gone for good again, but in 1949, one bull was spotted, and in 1954, people found a group on Guadalupe Island. In the half-century since then, and thanks to legal protection in both Mexico and the United States, the seals have made it back up to the Farallones once more, and their population is increasing.

Tagged as: endangered, humans, seal, threats

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Commerson’s Dolphin (Cephalorhynchus commersonii)

by JR Kinyak on March 25, 2009

in Marine Mammals

click image to enlarge

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This dolphin is also called the piebald dolphin. You know who else is piebald? The horse in National Velvet. That’s where I first learned the word. It’s a lovely word. It comes from the magpie, which is black and white, and an old definition of bald that meant “streaked with white.” The Pied Piper of Hamelin is so called because of his particolored outfit. Another nice word is skewbald, which means brown and white patches.

Oddly (I think it’s odd, anyway), there are two subspecies of Commerson’s dolphin found in two rather far-apart places, and that’s it. One group is around the Falkland Islands and the southern coasts of Chile and Argentina. The other is in the Kerguelen Islands, which are in the Indian Ocean some 3,000 miles southeast of Africa’s southern tip.

Tagged as: dolphin

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Mammals of Hawaii Week: Cuvier’s Beaked Whale (Ziphius cavirostris)

by JR Kinyak on January 20, 2009

in Marine Mammals,Theme Weeks

click image to enlarge

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Happy Inauguration Day! Today is the last day of our visit to President Obama’s (!!) home state. This funny guy is a Cuvier’s beaked whale, also called a goose-beaked whale. Even though Cuvier’s beaked whales are believed to be quite abundant, and even though they have an impressively large range, very little is known about them. They’re difficult to study because they seldom come to the surface. We do know, though, that they can dive deeper than any other air-breathing animal and that they hear through their throats (the sound travels to their ears through “a unique fatty channel”).

We also know that beaked whales seem especially susceptible to being harmed by naval sonar experiments and exercises. In 2000, several Cuvier’s beaked whales beached in the Bahamas, bleeding around their brains and ears, during naval exercises. Naval sonar has also been linked to mass strandings in the Mediterranean, the Madeira Islands, the Canary Islands, Japan, and the Gulf of California. The bad news for Hawaii’s beaked whales, reported last week, is that the U.S. Navy has been given a permit for a year of sonar and bomb training off the coast of Hawaii. The Navy is supposed to try not to harm marine mammals, but since no one knows exactly how sonar hurts the whales, how can we prevent it?

Tagged as: humans, threats, whale

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Mammals of Hawaii Week: Pantropical Spotted Dolphin (Stenella attenuata)

by JR Kinyak on January 18, 2009

in Marine Mammals,Theme Weeks

click image to enlarge

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Today we continue our look at the mammals of U.S. President-Elect Obama’s home state, Hawaii.

While Hawaii is rather short on native land mammals, it enjoys an abundance of native marine mammals. One of these is the pantropical spotted dolphin, which is found in all of the oceans in the world between 40ºN and 40ºS. As its name broadcasts, it’s characterized by its light-on-dark and dark-on-light spots, which increase with age.

You probably remember the public discussions and movements about dolphins and tuna fishing from the 1980s and early 1990s. The pantropical spotted dolphin is the species that was most affected by the tuna industry. You see, these dolphins have a close relationship—a loyalty almost—with yellowfin tuna. Before the 1950s, tuna had to be caught one at a time. Then advances in net technology made it possible to catch them in a big net called a purse seine. The best way to do this was to find their dolphin friends, who have to surface to breathe (unlike tuna, which are fish).

The idea was to catch the dolphins and tuna together, then release the dolphins, but catching the tuna was the priority, not saving the dolphins. The number of dolphins “accidentally” killed by tuna fishing since the 1950s is more than three times the number of whales killed—on purpose—by the commercial whaling industry in all of the 20th century.

Dolphins, the quintessential charismatic megafauna, were able to rally the support of the public, and a series of regulations, organizations, boycotts, and laws have brought the number of dolphins killed way, way down. Despite the Bush administration’s efforts to undermine the integrity of the Dolphin-Safe Tuna label, it’s now easy, in the U.S. and many other countries, to buy tuna caught without killing dolphins. (If your tuna doesn’t say dolphin-safe, it probably isn’t, so shop on the safe side.)

Unfortunately, the pantropical spotted dolphin has yet to recover from the years of dolphin-dangerous tuna fishing, and the IUCN calls it conservation-dependent. Here’s hoping Barack Obama will help protect his fellow native Hawaiians.

From NOAA: a good, brief primer on the tuna/dolphin issue.

Tagged as: dolphin, humans, threats

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Mammals of Hawaii Week: Hawaiian Monk Seal (Monachus schauinslandi)

by JR Kinyak on January 14, 2009

in Marine Mammals,Theme Weeks

click image to enlarge

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To celebrate the inauguration of President Barack Obama in a week, let’s meet some mammals of Hawaii, where Obama grew up.

Hawaii’s status as a volcanic island chain means any species there—of fish, lizards, trees, whatever—had to arrive there from somewhere else at some point. As far as I can ascertain, only one land mammal can call itself a native Hawaiian, and we’ll meet it tomorrow. Today, say hello to the Hawaiian monk seal, one of two mammals found on Hawaii and nowhere else.

The monk seal gets its name because of its solitary nature. The Hawaiian monk seal is now confined almost exclusively to the Leeward Islands, where the Polynesians never really settled. This endangered mammal just doesn’t do well with encroaching humans—who does, right? When a pregnant Hawaiian monk seal is annoyed by humans and their dogs, she’ll move somewhere else to give birth, and that somewhere else is often not a very good place to raise a baby. Humans’ fishing activities make it harder for the monk seals to find fish to eat, and they can get entangled in fishing nets and drown, too.

Mother Hawaiian monk seals stay with their babies for about six weeks after giving birth. During these weeks, the mother seals stop eating, losing a couple hundred pounds. (I can see the magazine covers now: “The Hawaiian Monk Seal Diet: From Baby Bump to Beach Body in Six Weeks!”) Most seals live in colder climates, and the Hawaiian monk seal doesn’t seem to have any adaptations for its tropical home. In fact, it has the same amount of blubber as polar seals. In the hottest part of the day, it hauls itself onto the beach to take a nap in wet sand, like the seal in this picture, or in the shade. (I hope the endangered-species policies of the new administration will help them sleep a little better.)

According to Walker’s Mammals of the World, “during the spring and summer adult males cruise constantly along favorite basking beaches in search of receptive females.” Sounds like humans!

Tagged as: endangered, humans, sleeping

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Minke Whale (Balaenoptera acutorostrata)

by JR Kinyak on January 7, 2009

in Marine Mammals

click image to enlarge

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It’s whale-hunting season again. And for the most part, it’s minke whales like this one who are being hunted. Minkes are small baleen whales that live in every ocean and some seas. (There is some controversy about whether there is one minke species or two—or more—but I’m staying out of it for now.) They weren’t hunted until recently—when they were about all that was left to hunt because other baleens had been killed to near extinction. While it’s thought that there’s currently a pretty healthy population of them, I don’t think anyone’s entirely sure exactly how many there are.

An international moratorium on commercial whaling took effect in 1986. Under the terms of the moratorium, member nations of the International Whaling Commission may not legally hunt whales, except for scientific purposes or, in some cases, by indigenous populations. If a country registered an official objection to that moratorium, it is not bound by its terms. That’s why Norway is allowed to kill some 1,000 minke whales a year. (It usually doesn’t kill nearly that many, though.) On the other hand, Japan registered an objection but then withdrew it; now Japanese ships kill more than 1,300 whales each year under the guise of “scientific research.” No one needs to kill that many whales to study them; no one needs to kill any whales to study them, really. The whales wind up, rather non-scientifically, on dinner plates.

Right now, a ship called the Steve Irwin operated by the Sea Shepherd Conservation Society is following the Japanese fleet in the Antarctic, “nonviolently harassing” the whalers in an attempt to make it more difficult for them to kill whales. (Apparently, even Greenpeace thinks these guys are extreme.) Yesterday, Japan asked Australia to deny the Steve Irwin access to its ports, which the ship needs to visit so it can refuel, a three-week process. Australia hasn’t said what it’s going to do yet. This past Monday, a Japanese sailor named Hajime Shirasaki went missing from one of the whaling ships; he is assumed to have fallen overboard and drowned. Sea Shepherd announced it would not “harass” the whalers while they were searching for its body, and the Steve Irwin crew, which has the only helicopter in the region, tried to join the search effort but was rejected by the angry Japanese whalers.

Meanwhile, a Japanese propaganda film has been posted on YouTube (read about it here; the article links to the actual movie, which I’m not watching) in an attempt to reveal Australians’ hypocrisy in their strict opposition to whaling while they abuse kangaroos. I say Australia and Japan are both wrong: leave the kangaroos and the whales alone.

January 6, 2009: “Japan Seeks Australia’s Help to Thwart Whaling Opponents,” NY Times
January 7, 2009: “Japanese Film Says Australians Abuse Animals,” Telegraph
January 7, 2009: “Angry Whalers Reject Sea Shepherd Help Offer,” The Age

NOAA’s Marine Fisheries Review has published a memoir by a Russian whaler in PDF form on its website. I haven’t read it yet but I think I’ll take a look.

Animal Planet has a show about the Steve Irwin and the Japanese fleet called Whale Wars. Have you seen it?

Tagged as: humans, taxonomy, threats

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Mammals of Iraq: Finless Porpoise (Neophocaena phocaenoides)

by JR Kinyak on July 30, 2008

in Marine Mammals,Theme Weeks

click image to enlarge

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This littlest of the cetaceans lives in the seas of Asia and the East Indies, including the Persian Gulf. So named because it lacks the dorsal fin that other porpoises have, the finless porpoise is a slow-moving fellow who frequently finds himself, an innocent byswimmer, killed by errant fishing methods. Sometimes he’s hunted for his meat, his skin, or his oil, too. Female finless porpoises have a neat child-rearing adaptation: there’s a rough spot on their backs that serves as a saddle where their babies can ride without slipping off.

Porpoises and dolphins are related, but they’re in different families.* There are a few characteristics you can use to tell them apart. Generally, dolphins have beaks while porpoises don’t, and porpoises have small, round heads. Porpoises, other than this species, anyway, have triangular dorsal fins, while dolphins’ dorsal fins are hooked. Also, porpoises have stockier bodies than the slender dolphins do.

Speaking of dolphins and the Persian Gulf, the US military has used dolphins, sea lions, and other marine mammals for reconnaissance and mine-finding missions for more than four decades, including in the Persian Gulf since at least the late 1980s. More recently, 152 dolphins mysteriously washed up dead on the shores of Iran: “Suicide or murder? Iran blames US after 152 dolphins die,” says the Guardian.

*Of course, this is controversial. Some scientists think dolphins and porpoises are members of the same family (the dolphin one, to be precise). As regular Daily Mammal readers know, we usually come down on the side of More Mammals! Also, here’s a helpful mnemonic device: Kids Pour Coke On Fat Green Snakes. What does it help me remember nearly every day?

Consecutive days of mammals: 1
Record: 16

Tagged as: dolphin, endangered, humans, porpoise, threats

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