Alaska‘s largest caribou herd continues to shrink as challenges on its huge range in Northwest Alaska continue to pose problems.
The Western Arctic Herd numbered about 325,000 animals, according to the most-recent census by the Alaska Department of Fish and Game. Although that’s just 5 percent less than the previous census in July 2009, it’s about a third smaller than the herd’s peak in 2003. Since then, the population has steadily declined 4 to 6 percent a year.
State wildlife biologists believe their counts are accurate. Caribou bunch up in tight groups in summer in response to harassment by flies and mosquitoes. Radio-collared caribou within the herd help biologists flying aerial surveys locate these groups. The number of known collared animals relative to the number actually found is an indicator of completeness.
“Out of 97 collared caribou, we found 96 of them during the census,” said area biologist Jim Dau, who has worked with the herd for decades. He said 97th collared caribou was located later, too.
Animals are photographed from the air with a special mapping camera and then counted on 9-by-9-inch contact prints. In a process that takes months, photos are laid out and overlap lines are drawn so animals are not counted twice or missed. In this recent count, the photographs were very clear, suggesting the 2011 census was reasonably accurate. Click Link Below For Full Story!