Tardy Gray Whales
STORY: When bird watchers taking part in the Audubon Society's annual count on Alaska's Kodiak Island looked seaward recently, they saw not birds, but hundreds of gray whales. Kate Wynne, a University of Alaska Fairbanks marine mammal scientist who lives on the island, says the spouting whales were easy to see.
WYNNE: "This year they looked out and saw hundreds of blows, literally. So what I think has happened is that the migration slid into this window when we had observers out there."
Yet by this time, the waters off Kodiak should be largely free of gray whales. Having spent the summer feeding in Alaska's Bering and Chukchi seas, gray whales usually migrate to the warmer waters off California and Mexico, where they mate and give birth.
But quite a few whales are still in Alaska. Exactly why is a mystery to scientists. Kate Wynne thinks the whales may have stuck around to take advantage of good feeding conditions in waters off Alaska. In most years, sea ice would force the whales south, but warm water this year has kept the Bering Sea mostly free of ice.
WYNNE: "In my mind there are two drives for any mammal. One is to eat, and one is to reproduce. And as long as you can keep doing one or the other, you're not going to budge. If you can eat as long as you can, until you know you have to reproduce, fine. And if you wait too long, you can't breathe now because there is now ice forming over your head. That's going to be the impetus for you to move. They may want to stay there longer and feed, except for the females that have to give birth. They may have been the first ones to go by here. I think for gray whales that since they go so far north, ice is going to definitely be one of the determinants of how long they can stay there. So if there's a lighter ice year, I think it would enable them to stay longer. In my mind they are opportunists. They eat as much as they can until they are forced to leave either by reproductive demands or by ice.
Dave Rugh, a biologist with the National Marine Fisheries Service in Seattle, Washington, has tracked gray whale migrations for nearly 30 years. Beginning in the mid-1990s, he says the migration started to run about one day later each year. He says pregnant females--the ones that most often lead the migration--are choosing instead to stay longer in Alaska waters.
RUGH: "The tidiest explanation is that the population has risen to the point that there is competition on the feeding range. The pregnant females are most sensitive, so they need to spend more time eating than they used to when there was less competition. So year after year there's more competition and they get later in their exit from the Bering and Chukchi seas. They come south later."
Dave Rugh says he doesn't know what effect this might have on calf survival, but he isn't too worried. The population is healthy, numbering about 24,000. And in 1995, gray whales were removed from the federal endangered species list.
RUGH: "Right now there are more calves. A lot of calves have been reported by shore-based observers. So things are still very productive."
When they do leave Alaska, gray whales pass very close to the rocky shores and cliffs of Kodiak Island. Kate Wynne says many of the 12,000 residents of the island turn out to watch the whales each spring and fall.
WYNNE: "They all pretty much go through Unimak Pass. So there's a funnel, and we're sort of in the bottleneck of that funnel. So we'll see gobs of them stream past here. We have a nice little spot on land to watch from. In the northbound migration they hug the shore a lot tighter. During the southbound migration they are a little bit further offshore. So we're seeing blows way out on the horizon at this time. But during the spring you can look down on them from the cliffs as they go by. They are that close."
They may be a few weeks late, but Alaska's gray whales appeared to be finally heading south when Kate Wynne last checked on their progress.
WYNNE: "The most I saw were 45 blows in the air during a sweep. And when I went out this Sunday I saw 15 or 16 blows in the same time frame. So I'm pretty sure the bulk of them are gone by now. But they were cruising. They weren't dilly-dallying. They were all moving by. They were out to the horizon, blows as far as you could see.
Gray whales range as far north as the Arctic Ocean above Alaska. They risk becoming trapped in sea ice if they wait too long before leaving. In 1985, several gray whales became trapped in ice off the coast of Barrow, Alaska. An international effort involving hundreds of people and a Soviet icebreaker was eventually able to free the whales.
OUTRO: For Arctic Science Journeys, this is Doug Schneider, reporting from Fairbanks, Alaska.
Arctic Science Journeys is a radio service highlighting science, culture, and the environment of the circumpolar north. Produced by the Alaska Sea Grant College Program and the University of Alaska Fairbanks.
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