'The Birds' Becomes Reality: Seagulls are Literally Pecking Whales to Death

Southern right whales are facing multiple threats to their population, and the latest is from birds.
These southern right whales are already classified as endangered, and now they face further threats. (Photo: Kim Westerskov/Getty Images)
May 10, 2013· 2 MIN READ
Joanna writes about environment and energy for the NYT, Popular Science, OnEarth Magazine, and more.

There is nothing quite as miraculously perfect as a newborn whale. Vicky Rowntree of Ocean Alliance has been studying southern right whales for decades, but she still catches her breath every time she captures a glimpse of these wondrous little creatures exploring the ocean for the first time.

"I know which whales are grandmothers and great grandmothers," says Rowntree. "I root for the families every year. The population is growing, but it's still just twenty percent of what it used to be before hunting, so every new calf is a celebration."

But something terrible is happening to southern right whales off the coast of Argentina. Those perfect little right whale calves have vicious scars all along their backs, and since 2003, nearly 605 whales have died.

Are the whales falling victim to some kind of environmental toxin? Is it food scarcity? Maybe climate change? Maybe, but the most obvious culprit are kelp seagulls, who in recent years, have developed the nasty habit of waiting for whales to surface and then ripping off large chunks of blubber and skin.

"These gulls are feeding on live whales," explains Rowntree. "We're not sure where this behavior came from, but the older gulls are teaching it to their chicks and it's spreading. We know the gulls have preyed on other sea birds in the past and even pecked out the eyeballs of newborn lambs. Now it seems they've settled on mother and calf right whales."

Adult right whales are responding to the onslaught by arching their backs while close to the surface to avoid getting landed on by the gulls. But the baby right whales haven't learned this trick yet, and newborn whales need to come to the surface every twenty seconds to breathe, so they're constantly exposing themselves to attack.

Rowntree hasn't found any evidence to suggest that the right whales are dying of infection caused by the gull-inflicted wounds. But the persistent nature of the attacks may well interrupt mothers trying to feed their calves, or the constant avoidance of gulls may dip dangerously into the mothers' limited energy reserves.

"Mother whales don't eat for three months after giving birth," says Rowntree. "They are using huge amounts of energy to feed their calves, so any additional movement that the gulls are forcing may mean they don't have the fat reserves to properly nourish their babies."

Rowntree doesn't know for sure why the gulls have caused such problems in recent tears, but she suspects that open landfills and fish processing plants that dump waste into the ocean are helping support the ever-growing gull population.

Unfortunately, even if the kelp gull numbers could be kept in check through limiting their food supply during the months when the right whales are at sea, the whales still face other threats.

"I don't believe that it is just the gulls that are causing this incredible level of mortality," said Rowntree. "It is quite possible that the gulls are just exacerbating the mothers' already poor nutritional state."

Warming ocean temperatures are believed to be a serious threat to krill populations, the primary food source of right whales and hundreds of other marine animals. Krill feed on the algae growing on the bottom of ice sheets, so fewer ice sheets as the oceans warm, translates to fewer krill and less food for whales.

"Getting the Argentine government to cover landfills and sink fish processing waste seems like a formidable task in itself," says Rowntree. "Protecting krill populations requires that the whole world take action."

Besides hindering the seagull population, what else should we be doing to protect the southern right whales? Let us know in the Comments.