Evaluating Potential Effects of an Industrial Road on Winter Habitat of Caribou in North-Central Alaska

Abstract

ABSTRACT. Worldwide, some caribou (Rangifer tarandus) populations are experiencing declines due partially to the expansion of industrial development. Caribou can exhibit behavioral avoidance of development, leading to indirect habitat loss, even if the actual footprint is small. Thus, it is important to understand before construction begins how much habitat might be affected by proposed development. In northern Alaska, an industrial road that has been proposed to facilitate mining transects a portion of the Western Arctic caribou herd's winter range. To understand how winter habitat use might be affected by the road, we estimated resource selection patterns during winter for caribou in a study area surrounding the proposed road. We assessed the reductions of habitat value associated with three proposed routes at three distance thresholds for disturbance. High-value winter habitat tended to occur in locally rugged areas that have not burned recently and have a high density of lichen and early dates of spring snowmelt. We found that 1.5% to 8.5% (146-848 km 2 ) of existing high-value winter habitat in our study area might be reduced in quality. The three alternative routes were only marginally different. Our results suggest that the road would have minimal direct effects on high-value winter habitat; however, additional cumulative impacts to caribou (e.g., increased access by recreationists and hunters) should be considered before the full effects of the road can be estimated.Key words: Alaska, caribou, development, Rangifer tarandus, resource selection, roads, winter RÉSUMÉ. À l'échelle mondiale, certaines populations de caribous (Rangifer tarandus) connaissent des déclins partiellement attribuables à l'expansion industrielle. Pour des raisons de comportement, le caribou peut éviter le développement, ce qui entraîne une perte d'habitat indirecte, et ce, même si la place réellement occupée est petite. Par conséquent, il est important de comprendre, avant même que des travaux de construction ne soient amorcés, dans quelle mesure l'habitat sera touché par les travaux proposés. Dans le nord de l'Alaska, une route industrielle dont la construction a été proposée pour faciliter l'exploitation minière coupe transversalement une partie de l'aire d'hivernage du troupeau de caribous de l'ouest de l'Arctique. Afin de comprendre comment l'utilisation de l'habitat d'hivernage pourrait être touchée par la route, nous avons estimé des modèles de sélection des ressources pendant l'hiver pour le caribou se trouvant dans une aire d'étude entourant la route proposée. Nous avons évalué la diminution de la valeur de l'habitat liée à trois routes proposées à trois seuils de distance afin d'en déterminer la perturbation. Un habitat d'hivernage de grande valeur avait tendance à se manifester dans les régions locales accidentées qui n'avaient pas fait l'objet de brûlages récents, régions caractérisées par une forte densité de lichen et une fonte des neiges hâtive au printemps. Dans le cadre de notre étude, nous avons constaté que la qual...

Effects of roads on individual caribou movements during migration

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