{"id":32827,"date":"2020-10-15T00:05:30","date_gmt":"2020-10-15T07:05:30","guid":{"rendered":"https:\/\/hakaimagazine.com\/?post_type=custom_news&p=32827"},"modified":"2022-08-11T13:26:31","modified_gmt":"2022-08-11T20:26:31","slug":"peck-by-peck-seabirds-are-eating-live-whales","status":"publish","type":"custom_news","link":"https:\/\/hakaimagazine.com\/news\/peck-by-peck-seabirds-are-eating-live-whales\/","title":{"rendered":"Peck by Peck, Seabirds Are Eating Live Whales"},"content":{"rendered":"

Seabirds are skilled opportunists, commonly flocking to fishing boats to scavenge on scraps thrown overboard<\/a>. Now, researchers have documented one large, notoriously aggressive species exploiting fishing operations in an unusual way\u2014by taking bites out of the whales<\/a> they attract.<\/p>\n

In 2015, Jared Towers, a cetacean ecologist at the British Columbia\u2013based research organization Bay Cetology, boarded a fishing vessel that was in search of Patagonian toothfish, a lucrative cod species also known as Chilean sea bass. Towers wasn\u2019t interested in the fish, but in the sperm whales they lure\u2014the whales have learned to pilfer meals<\/a> off the fishers\u2019 longlines. While at sea in the South Atlantic, Towers noticed something bizarre: just as a sperm whale surfaced to breathe, a giant petrel swooped down and ripped a morsel of skin and blubber out of its back.<\/p>\n

On that trip alone, Towers saw giant petrels take bites out of surfaced whales more than a dozen times. Combining his sightings with those made by fisheries observers between 1997 and 2019, Towers and his colleagues report in a new paper 23 cases of giant petrels preying on whales. \u201cThat\u2019s a minimum,\u201d Towers says.<\/p>\n

Though the idea of birds eating live whales is surprising, this isn\u2019t the only instance of birds feeding on much larger animals. Researchers have previously witnessed giant petrels biting live sheep, and oxpeckers consuming rhinoceroses\u2019 skin and blood<\/a>. And like giant petrels, kelp gulls have been known to peck at whales, too.<\/p>\n

Off the coast of Argentina\u2019s Valdes Peninsula, kelp gulls\u2019 attacks on southern right whales can last more than an hour, says Mariano Sironi, scientific director of Argentina\u2019s Instituto de Conservaci\u00f3n de Ballenas (Whale Conservation Institute) who was not involved in Towers’s research. He says the relentless pecking creates craters in the whales\u2019 skin, and causes a great deal of stress for the animals.<\/p>\n

Your browser does not support the video element.<\/p><\/video>\n

Scientists suspect seabirds\u2019 attacks contribute to whale stress and potentially calf mortality. Video by Mariano Sironi\/Instituto de Conservaci\u00f3n de Ballenas, Argentina <\/span><\/p>\n

Those attacks have intensified in recent years, he adds, in part because discarded food from fishing boats and open-air dumps is sustaining an artificially large gull population. From the 1970s to the 2000s, the proportion of whales with gull wounds increased from two to 99 percent. Sironi says the birds\u2019 assaults may also be contributing to the area\u2019s high death rate for whale calves.<\/p>\n

Researchers, Sironi says, might be witnessing the beginning of a growing problem in the subantarctic, similar to what scientists began recording in Argentina five decades ago.<\/p>\n

For now, giant petrels aren\u2019t attacking whales nearly as often as kelp gulls are. But just as human activities inflated the gulls\u2019 numbers, the same could prove true for giant petrels\u2014with potentially harmful results for the whales.<\/p>\n

\u201cBecause longlining activities provide feeding opportunities for whales and birds, you have these unnaturally large aggregations of both,\u201d Towers says. Whales also dive deep, fast, and for long periods when stealing fish off the longlines, which forces them to spend several minutes at the surface to catch their breath. That may be offering petrels the perfect opportunity to take a bite.<\/p>\n

Towers says the birds\u2019 new taste for sperm whale highlights how nearly every human activity affects ecosystems\u2014sometimes in unexpected ways.<\/p>\n","protected":false},"excerpt":{"rendered":"

Seabirds are skilled opportunists, commonly flocking to fishing boats to scavenge on scraps thrown overboard. Now, researchers have documented one large, notoriously aggressive species exploiting fishing operations in an unusual way\u2014by taking bites out of the whales they attract. In <\/p>\n

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