Wednesday, March 23, 2011

At least 32 musk oxen perish in storm surge in Alaska preserve


At least 32 musk oxen in the Bering Land Bridge National Preserve perished during a nasty storm surge last month, and officials are worried many more may be buried deeper in the ice and out of sight.
The carcasses were discovered March 15 frozen in ice on the northern coast of the Seward Peninsula by researchers studying the animals, according to the National Park Service. Four of them had been fitted with radio collars a month earlier, part of a five-year federal study on musk ox population in the Northwest. At that time, some 55 of the animals were gathered together.
The oxen calamity took place within the boundaries of the 2.6 million-acre Bering Land Bridge National Preserve. Shishmaref is the nearest village. The preserve is a remnant of the land bridge that connected Asia with North America some 13,000 years ago. Alaska wildlife biologist Tony Gorn of Nome visited the site on Friday.
He saw remains strewn over nearly a half-mile. "It's pretty interesting," he said. "The carcasses are spread out over several hundred yards, and on the periphery are some young animals. That's terribly unusual."
When threatened, musk ox typically bunch up, with younger animals in the middle. And despite being among the best-insulated animals on Earth, the oxen probably died of exposure, Gorn said. "They do have unbelievable insulating qualities," he said. "But that ends at their legs, which don't have that long hair you see on their bellies. They didn't get wet, they got saturated. They may have drowned, but it's possible they became completely saturated and died from exposure."
Most animals died lying on their sides, Gorn said. However, he saw at least one frozen bull that "looks like it's just standing there."
Even such mass deaths may not harm a healthy population of Seward Peninsula musk oxen, which has grown from 104 animals in 1980 to more than 3,000 animals today. "The population will certainly recover from that," said Jim Lawler, a park service biologist based in Fairbanks who regularly works in the region. "Of course, you don't ever want to lose as many as that in a fell swoop. It's a good number of animals but it's not that big of a deal."
While the growth of the herd has slowed considerably in recent years, "it was going gangbusters there for a time, growing 12-14 percent a year," Lawler said.
Gorn, however, pointed to some recent trouble signs. "There are lots of red flags," he said. "Just about everything you look at is alarming. Mature bull-to-cows ratios are declining. Population growth is slowing."
On Feb. 25, according to John Lingaas, warning coordination meteorologist with the National Weather Service in Fairbanks, the Northwest was in the middle of a major storm that saw tides rise nearly 7 feet. Over the course of about six hours, there was a sudden two-foot spike, Lingaas said. Those measurements were made near Kivalina on the other side of Kotzebue Sound, he added. "The slow rising water over the previous days may have trapped them in a certain place," Lingass said, "and the spike may have been enough to kill them." Lingass said such tidal surges typically happen in October or November, not February.
"One of the things you see if you spend time watching musk ox," Gorn said, "is that those animals seem to be really confused by rising water. You'll see them isolated on a spit or an island. Even though it's apparent they have to walk through a couple feet of water to get to drier land, they don't do it."

And late in winter, Lawler noted, distinguishing ice-covered land from ice-covered water on the low-lying Seward Peninsula can be impossible. "That northern end of the peninsula is very flat, and they would have to go a substantial distance to get away from the tide," Lawler said. "My guess is that the animals don't know where to go.
"My guess is that they had a strong storm surge. There were winds of more than 50 mph measured. You get that wind whipping, and it pushed all kinds of water and ice pancakes up."
The same storm put the 2,000-mile Iron Dog snowmachine race from Big Lake to Nome to Fairbanks on hold near the turnaround in Nome. On Tuesday, park service scientists flew to the area to see if they could determine the fate of other animals in the 55-oxen group. "We didn't see any carcasses," Quinley said. "But we didn't see them walking around (either)."
The park service plans to take tooth and bone samples to determine the age and health of the musk oxen that perished. The park service also is warning people in nearby villages and researchers who may be in the area to be aware that other predators - including brown bears, possibly polar bears, wolverines and foxes - may be drawn to the carcasses.
The service also is reminding people that it's illegal to remove horns from national park lands, and that this meat is likely not salvageable or palatable, Quinley said.
Musk oxen from Greenland first arrived in Alaska in the 1930s, with a small group transplanted to Nunivak Island. In 1970, three dozen of the Nunivak Island animals were transplanted near the Feather River, about 36 miles from Nome. A second transplant came in 1981 with the release of 35 more animals at the Port Clarence Coast Guard Station, 15 miles west of Teller.
A Fish and Game survey in 2007 found 2,688 of the herbivores, which can weigh upwards of 800 pounds. Gorn said the current estimate is 3,434 for the entire area.

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