Smithsonian.com

Squeaking in under a Thursday deadline, the U.S. Department of the Interior officially made the decision to list the polar bear as threatened under the Endangered Species Act. The government’s move appeared to have come somewhat grudgingly, in response to a judge’s order to end five months of hemming and hawing.

As many as 25,000 polar bears roam the Arctic today. But that number is likely to drop drastically as the climate warms and perhaps two-thirds of the Arctic summer sea ice melts by 2050 (as the L.A. Times summarizes). Concern over the fate of polar bears escalated last year as sea-ice melting reached historic highs and the Northwest Passage opened for the first time ever. Polar bears hunt for seals by roaming vast expanses of sea ice; when confined to land, they are much more likely to go hungry.

The great bears have more worries than just global warming. In a northern-hemisphere parallel with pesticide-laden penguins we mentioned last week, polar bears in remote Svalbard have some of the highest organic pollutant levels measured in any animal.

Interior Secretary Dirk Kempthorne seemed to hold little enthusiasm for the idea of using the Endangered Species Act as a way to spur the U.S. to curb its emissions. At least his language was forceful, and he hit the larger predicament dead-on. According to the Washington Post:

I want to make clear that this listing will not stop global climate change or prevent any sea ice from melting,” Kempthorne said. “Any real solution requires action by all major economies for it to be effective.

Hear, hear.
(Image: Alaska Image Library/U.S. Fish and Wildlife Service)

A decade ago, thanks to the Federal Endangered Species Act, gray wolves were reintroduced into Yellowstone National Park. Conservationists have since used radio collars and overhead surveillance technologies to keep track of the animals’ whereabouts. But at the end of this month, federal support will dissolve—meaning scientists will no longer be able to use the expensive equipment.

But a new, cheaper technology might save the day. “Howlbox,” developed by scientists at the University of Montana in Missoula, is a $1,300 speaker-recorder system that broadcasts digitized wolf howls and then records any real howls that respond to the fakes. The system is pretty sophisticated: a precise frequency analysis of the recordings shows not only how many wolves responded, but which specific ones did.

The Howlbox was tested in one spot in Montana in January. The University of Montana’s pilot project, involving four remote sites in Idaho, is slated for June.

The biggest problem with the box might not be the response from wolves, but from humans. As this NYT article points out:

To the uninitiated, a Howlbox-enhanced forest could sound as if wolves were everywhere—a scary proposition. Montana wildlife officials are braced for a public relations campaign if the project moves forward.

(Flickr, by Hare Guizer)

Last July, as we began to prepare an article about the mountain gorillas of Congo and Rwanda (Guerrillas in Their Midst) for the magazine, we received the horrible news that one of the gorilla families our author visited had been the victims of a brutal crime. Four gorillas—including the silverback Rugendo—had been killed. By the end of 2007, the body count at Virunga National Park reached ten. And to make the situation even worse, rebel forces had taken over the park and barred the rangers. Thus, the gorillas have gone unwatched and unprotected for months.

Today comes the news, though, that an arrest has been made in the case of last year’s gorilla killings. Honore Mashagiro, the head of the park’s southern sector, has been accused of organizing the killings, and six other foresters may be questioned about their role, BBC News reports. The gorillas may have been killed to divert attention from the illicit trade in a coal-like mineral called makala (according to the AFP) or the destruction of the forest to make charcoal (see the Gorilla Protection blog).

It’s rough making it through the depths of winter as a squirrel. Your best bet is to make a warm nest up in a tree and spend the summer burying as many nuts as possible for later. But watch out for blue jays, who aren’t above spying on your stash, then digging the seeds back up when you’ve left.

Scientists have long watched – no doubt with a mixture of amazement and pity – industrious squirrels burying their supper only to have a jay (or another squirrel) dig it right back up again. Now, in the March issue of American Naturalist, they report that squirrels aren’t taking this abuse sitting down. They seem to have taken a key trait of blue jays – their incessant jabbering – and turned it against them.

Turns out that squirrels keep one ear tuned to the treetops. If they hear a volley of jay calls while they’re out nut-hunting, they’re less likely to waste time burying what they find. They turn from squirreling them away to wolfing them down.
The authors sum it up this way (opting for delicious vocabulary):

We conclude that through eavesdropping, squirrels assess site-specific risks of cache pilfering and alter their caching behavior to reduce the likelihood of pilferage.

To come to this conclusion, the authors set out hundreds of trays of hazelnuts (shelled and unshelled) in the woods of New York. As the resident squirrels were discovering their windfall, some of them heard the cries of blue jays echoing over their heads. Others heard the sounds of more honest neighbors such as cardinals, bluebirds, and goldfinches. (The squirrels were presumably unaware the calls were coming from a speaker lodged on a nearby tree branch.)

So what happened? Squirrels that were barraged with blue-jay calls gave up digging an average of two hazelnuts earlier than squirrels whose ears told them the coast was clear – figuring that hiding all those free nuts was just not worth all the hard work, especially out in the open under watchful eyes. Instead, they just started eating them. In animal behaviorese:

Under diminishing returns, an animal should exploit a patch until its harvest rate (H) declines to the sum of its foraging costs, which include metabolic (C), predation (P), and missed-opportunity costs (MOC); that is, the point at which H = C + P + MOC (Brown 1988).

I love painstaking field research on obscure topics like this.

But then, is it so obscure? The result, the authors point out, is a valuable reminder that communication is rarely just a two-way street. Eavesdroppers are everywhere, and yet it’s amazing how freely we send out information into the air. Thinking about it helps me remain philosophical whenever I find myself on public transit, trapped on the fringe of an uncomfortably personal cell-phone conversation.

(Flickr: smellyknee)

Ever since humanity made it past the large-animals-eat-us stage, history has not been kind to carnivores. But beginning in the mid-twentieth century – around the time Aldo Leopold famously watched a “green fire” die from the eyes of a wolf he’d just shot – some Americans began to regret the disappearance of the food chain’s brawniest and most fearsome rung.

Gradually, through habitat conservation, establishment of wildlife corridors, and painstaking reintroductions, we started to encourage the likes of grizzlies, wolves, Florida panthers, California condors, and peregrine falcons to return.

It’s been a long wait. But this week two bolts from the blue arrived. In California’s Sierra Nevada, a graduate student’s automatic camera took the first-ever photo of a wolverine in the Sierra Nevada. The ferocious, oversized weasels have been gone from California for at least 80 years. No one knows where this one came from – fitting considering these irascible animals’ reputation for roaming enormous acreages, mostly above treeline, looking to fight for their supper.

And three thousand miles away, in Massachusetts, a landowner shot a big gray dog, only to find it was the state’s first gray wolf in 160 years.

It’s a promising sign. Wolves tend to go walkabout when their home pack’s territory starts to get packed. They, too, have a tremendous ability to wander, as sightings in Oregon over the past several years demonstrate. Most arrive from Idaho, undeterred by the swim across the Snake River. In January, a female wolf made the trip while wearing a radio collar, putting to rest any doubts about where it came from.

No one knows exactly where the Massachusetts wolf came from – presumably snowy Canada. But Canada is a large place, which brings up another recent news item: tracing people through the analysis of stable isotopes found in their hair. The technique gives a rough idea of where an animal lived based on hydrogen atoms contained in the rainwater it drinks. Since the stray wolf has already been shot dead, could a little more analysis narrow down where it came from?

Hat tip: the Knight Science Journalism Tracker

(Image: wolverine by Katie Moriarty/ Oregon State University/ U.S. Forest Service)