Unimak Caribou Herd
Ongoing Issues — Overview
In 2006, Alaska Department of Fish and Game (ADF&G) surveys revealed extremely low calf recruitment (fewer than 1 calf per 100 cows survived to four months of age) on the Southern Alaska Peninsula caribou herd (SAP) despite overall good health and high calf production. All available evidence indicated that predation on very young calves was very high. Although the small amount of hunting was eliminated, bull numbers continued to decline. Based on herd composition and our understanding of caribou biology, managers determined that bull numbers might get very low and prevent the herd from recovering to huntable status.
In 2008–2010, ADF&G implemented a selective wolf control program on the SAP calving grounds that dramatically increased calf recruitment (more than 39 calves per 100 cows were surviving to four months of age). The program was so successful that it has been paused and will only be re-implemented if calf recruitment drops below 20 calves per 100 cows. Only 22 adult wolves were killed over three years. Young of the year were euthanized in dens (relocation was not possible due to concern for rabies).
The adjacent Northern Alaska Peninsula (NAP) and Unimak Island herds (UCH) served as scientific comparisons for the SAP program. Neither herd showed significant increases in calf recruitment during the same time period. In fact, the UCH population experienced exactly the poor performance (low calf recruitment and declining bull numbers) managers had feared would occur to the SAP without removing wolves.
By autumn 2009, surveys revealed that UCH bull numbers had declined to the lowest ever reported for a caribou herd in Alaska despite a discontinuation of hunting, and overall good health (indicated by body condition and calf weights) and calf production. Rather than let the UCH further decline, risk extirpation—or, in the best case—remain closed to hunting for years or decades, ADF&G proposed conducting a selective wolf removal program on Unimak similar to that done for the SAP. The best available science clearly indicated that the program would likely decrease the number of years that hunting would be closed on Unimak and prevent possible extirpation of the herd. ADF&G conducted an Environmental Review in April 2010 that considered different alternatives for Unimak and determined that selectively removing wolves was the best solution to maintain both wolves and caribou.
Using this same science, the Environmental Analysis (EA) conducted by the USFWS under NEPA concluded that a wolf reduction program was necessary to meet mandates to provide for subsistence use of caribou on the Island and conserve caribou and wolves. However, the USFWS subsequently released a record of decision to take no action to provide for subsistence uses or conserve caribou through wolf reduction.