Subpopulation structure of caribou (Rangifer tarandusL.) in arctic and subarctic Canada

Abstract

Effective management and conservation of species, subspecies, or ecotypes require an understanding of how populations are structured in space. We used satellite-tracking locations and hierarchical and fuzzy clustering to quantify subpopulations within the behaviorally different barren-ground caribou (Rangifer tarandus groenlandicus), Dolphin and Union island caribou (R. t. groenlandicus x pearyi), and boreal (R. t. caribou) caribou ecotypes in the Northwest Territories and Nunavut, Canada. Using a novel approach, we verified that the previously recognized Cape Bathurst, Bluenose-West, Bluenose-East, Bathurst, Beverly, Qamanirjuaq, and Lorillard barren-ground subpopulations were robust and that the Queen Maude Gulf and Wager Bay barren-ground subpopulations were organized as individuals. Dolphin and Union island and boreal caribou formed one and two distinct subpopulation, respectively, and were organized as individuals. Robust subpopulations were structured by strong annual spatial affiliation among females; subpopulations organized as individuals were structured by migratory connectivity, barriers to movement, and/or habitat discontinuity. One barren-ground subpopulation used two calving grounds, and one calving ground was used by two barren-ground subpopulations, indicating that these caribou cannot be reliably assigned to subpopulations solely by calving-ground use. They should be classified by annual spatial affiliation among females. Annual-range size and path lengths varied significantly among ecotypes, including mountain woodland caribou (R. t. caribou), and reflected behavioral differences. An east-west cline in annual-range sizes and path lengths among migratory barren-ground subpopulations likely reflected differences in subpopulation size and habitat conditions and further supported the subpopulation structure identified.

Assessing polar bear (Ursus maritimus) population structure in the Hudson Bay region using SNPs

“…SNPs are a powerful resource to aid in the challenge of establishing clear subpopulation boundaries for management of wide‐ranging species. Traditionally, an a priori approach using geographic and political information is often implemented (Cegelski et al., 2003; Nagy et al., 2011; Vähä, Erkinaro, Niemelä, & Primmer, 2007). However, genetic structure detected in analyses using geopolitically informed boundaries could mask true genetic structure and mislead interpretations of genetic clusters (Meirmans, 2015).…”

Have geographical influences and changing abundance led to sub-population structure in the Ahiak caribou herd, Nunavut, Canada?

“…In July 2007, the collaring was conducted on the post-calving range (Johnson & Fleck, 2009 We compiled a database using collared cows with at least one calving location on Queen Maud Gulf coastal calving ground 1996-2010. We also included those cows with a history of calving on the traditional Beverly calving grounds (south of Garry Lakes) but which had shifted to the Queen Maud Gulf coastal calving ground (Nagy et al, 2011;Gunn et al, 2012). Calving date was based on examination of daily movement rates coupled with spatial movements in GIS, such that calving was determined from a rapid drop in daily movement rate (generally to <2 km/day) and localization, followed by a 5-10 day period of reduced movement (Fancy & Whitten, 1991).…”

Do human activity and infrastructure disturb domesticated reindeer? The need for the reindeer’s perspective

“…Obstructions caused by human activity and infrastructure are likely to affect reindeer's choice of seasonal ranges (Senft et al 1987), which typically cover broad geographic extents (Nagy et al 2011). To understand the consequences of anthropogenic disturbance on reindeer (or other large herbivores), it is thus necessary to study effects over a variety of scales.…”