What the author of that article fails to mention is the fact that the "short" period of time the caribou herds inhabit the area targeted for oil extraction just happens to be the most important time for the long term survival of the herd. Calving time.

http://www.taiga.net/coop/indics/pchcalv.html

http://www.absc.usgs.gov/1002/section3part1.htm


http://web.mit.edu/12.000/www/m2007/teams/finalwebsite/environment/te_pcaribou.html

"The Coastal Plain is vital to the calves� survival for two main reasons:

1)    fewer brown bears, wolves, and golden eagles live on the coastal plain so newborns have greater chance of survival in their first week until they are strong enough to outrun their predators. (USGS Fish and Wildlife, 2003)

2) Coastal Plain provides proper nutrition needed for calving. There is an abundance of plant species and after a long winter, the cows need to have good nutrition"


http://arcticcircle.uconn.edu/ANWR/anwrcaribouscience.html

Before authorizing oil leasing within the Arctic National Wildlife Refuge, Congress should consider that the Porcupine Caribou Herd is much more concentrated on its calving ground than the smaller Central Arctic Herd and may therefore be more vulnerable t o disturbance. Although calving has occurred historically over a fairly targe area of the North Slope in Alaska and the Yukon Territory, most calves are usually born in a smaller region that includes much of the area being considered for oil development ( Fancy and Whitten 1991). During late June and early July, essentially all cows and calves and many bulls of the Porcupine Herd use the potential development area every year.

Calf survival is generally high when the Porcupine Herd calves in the traditional coastal plain area that includes the potential oil lease area (Fancy and Whitten 1991, Whitten et al. 1992). Rapid, nutritious plant growth often occurs in this area during calving (National Biological Service, unpubl.). The coastal plain calving area is also relatively free of predators, and calf survival declines when late snow melt forces caribou to calve in nearby mountains and foothills where wolves, grizzly bears and g olden eagles abound (Whitten et al. 1992). The Porcupine Herd is already large and near its historic population high. If petroleum development were to displace it from part of its traditional calving grounds, suitable alternative habitat might not be avai lable. Consequently, the Porcupine Herd might not fare as well as the Central Arctic Herd apparently did during the early years of Prudhoe Bay.

Porcupine caribou normally herd in much larger groups than Central Arctic Herd caribou. Studies in the Prudhoe Bay and Kuparuk oilfields show that larger groups (100 or more caribou) have difficulty crossing roads and pipes ( Smith and Cameron 1985). Grou ps of several thousand caribou occur throughout the summer in the Porcupine Herd, and from mid-June through July, group sizes in the tens of thousands are common.

In summary, development of the Prudoe Bay oil field displaced caribou and disrupted their movements. Similar long-term displacement now appears to be occurring elsewhere, even in the "state-of-the-art" Kuparuk and Milne Pt. Oil fields. Mitigation measures proposed for Arctic Refuge oil fields will likely be even less effective in allowing access to critical habitats for the larger, more densely aggregated Porcupine Herd. The caribou resources at risk in the Arctic National Wildlife for petroleum developme nt far exceed those found at Prudhoe Bay. Development of the coastal plain may well cause a long-term decline in calf survival, thereby decreasing population size over time, with serious consequences for many residents in both Canada and the U.S.