SCOTT SIMON, host: On a remote, treeless island 60 miles south of Alaska's Prince William Sound, an old military radar tower has become one of the best bird observation sites in the world. Hundreds of black-legged kittiwakes nest on the tower. And one researcher has discovered, the seabirds may be quite adept at responding to a changing environment. Alaska Public Radio Network's Annie Feidt reports.
ANNIE FEIDT: The hulking concrete tower on Middleton Island isn't much to look at. But in 1986, a few black-legged kittiwakes took a liking to it. United States Geological Survey biologist Scott Hatch saw possibility.
SCOTT HATCH: Looking at the building I thought hmm, I mean this is kind of a cool situation where the birds are nesting on a building, that you could go inside and potentially could be looking from the inside out at the birds.
FEIDT: These days, the tower is a giant bird hotel, with nearly 600 kittiwake suites. Hatch installed one-way mirrored glass so he can see out, but the birds can't see in. He took an audio recorder with him on a trip to Middleton this spring and describes the scene.
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HATCH: These windows are really pretty remarkable. You can get to within inches of the birds you're observing. I like to tell people - sort of tongue in cheek - you can literally do smoosh faces on the window.
FEIDT: Hatch calls kittiwakes the white lab rats of the seabird world because they're so common and easy to study. But over the years, the Middleton Island kittiwakes have revealed some intriguing facts about themselves. For one thing, they are terrible breeders. And by terrible, I mean, pink flannel nightgown bad.
HATCH: In Alaska, kittiwakes had abject breeding failure. I mean, zero young produced in many colonies for many years, and Middleton Island was maybe the best example of that.
FEIDT: But a researcher studying the same birds several decades ago in England found just the opposite. Those North Atlantic kittiwakes raised lots of chicks, and they had short lifespans - living about 10 years. Hatch realized the Alaskan kittiwakes were probably living longer.
HATCH: And so I hypothesized, reasonably enough, that they must have very high survival to compensate, otherwise we should have been out of kittiwakes a long time ago.
FEIDT: It turned out to be true. The Alaskan kittiwakes live about 20 years, twice as long as their North Atlantic counterparts. And much of Hatch's research since has been devoted to figuring out why.
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HATCH: All right. She looks pretty happy.
FEIDT: This spring, Hatch put GPS bands on several birds.
HATCH: She looks good to go. Now you go do some nice feeding. Ow.
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FEIDT: Hatch thinks the birds' reproductive woes have to do with their diet, so these GPS bands will help him learn where they're getting their food and what they're eating.
HATCH: Now, let's look for our next victim.
FEIDT: He also wants to know if feeding the kittiwakes makes a difference. So he began offering fish to some of the birds. It's an all-you-can eat type of arrangement. And this spring, the kittiwakes had healthy appetites.
HATCH: The bird in A-24 has just eaten seven fish. That's not a record. I think the record was nine fish at one meal.
FEIDT: Hatch wondered if these well-fed Alaskan kittiwakes would start to act more like North Atlantic kittiwakes, and very quickly, within one year, they raised many more chicks. The next question was whether their life span would decrease. And the preliminary data suggests the answer is yes.
HATCH: The survival rates are coming down accordingly.
FEIDT: This reproductive phenomenon is well-known between different animal species. Mice have lots of young, but short lives. Elephants live a long time, but don't raise many offspring. But Hatch says it's rare to discover a single species with two reproductive patterns.
HATCH: It's kind of a strategy, it's a game. Do I, you know, put all my eggs into - or maybe a poor - not a pun intended - but do I put my effort into breeding, and therefore not live as long, or do I kind of sit it out, live a long time and hope that I'll have adequate reproduction over the long term?
FEIDT: The conventional wisdom is that if you reduce birds' food supply, their population numbers will suffer. But the kittiwakes' flexibility has allowed them to do well when their favorite fish is plentiful or scarce, in the Atlantic or Pacific. Hatch says usually biologists like himself tell tales of gloom and doom, but the kittiwakes' story may be different.
HATCH: Many wildlife populations may operate like this. And so, let's factor that into our thinking, rather than throwing up our hands and assuming that all is lost. It could be that populations will adapt in ways that they've already demonstrated they're capable of doing, and in ways that are a little more palatable than simply going through the floor when we bugger their food supply.
FEIDT: Hatch doesn't want to minimize very real threats like climate change. But, he says, in some cases, the effect may not be as bleak as many assume. And the Middleton Island kittiwakes, with their flexible life spans, may be a good example of that.
For NPR News, I'm Annie Feidt in Anchorage.
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