Abstract
Migratory barren-ground caribou (Rangifer tarandus groenlandicus) provide an opportunity to examine the genetic population structure of a migratory large mammal whose movements and distribution, in some instances, have not been heavily influenced by human activities that result in habitat loss or fragmentation. These caribou have likely reached large effective population sizes since their rapid radiation during the early Holocene despite cyclic changes in abundance. Migratory barren-ground caribou are managed as discrete subpopulations. We investigated genetic variation among those subpopulations to determine the patterns of genetic diversity within and among them, and the implications for long-term persistence of caribou. We identified three distinct genetic clusters across the Canadian arctic tundra: the first cluster consisted of all fully-continental migratory barren-ground subpopulations; the second cluster was the Dolphin and Union caribou; and the third cluster was caribou from Southampton Island. The Southampton Island caribou are especially genetically distinct from the other barren-ground type caribou. Gene flow among subpopulations varied across the range. Occasional gene flow across the sea-ice is likely the reason for high levels of genetic variation in the Dolphin and Union subpopulation, which experienced very low numbers in the past. These results suggest that for most migratory caribou subpopulations, connectivity among subpopulations plays an important role in maintaining natural genetic diversity. Our analyses provide insight into the levels of microsatellite genetic diversity and patterns of gene flow that may be common to large subpopulations that historically had a continuous distribution across a large continental range. These data can also be used as a benchmark to compare the effects of habitat fragmentation and bottlenecks on other large caribou populations.
Highlights
Our analyses provide insight into the levels of microsatellite genetic diversity and patterns of gene flow that may be common to large subpopulations that historically had a continuous distribution across a large continental range
Migratory barren-ground caribou (Rangifer tarandus groenlandicus) provide the opportunity to examine the genetic population structure of a large mammal that, in many instances, still has much of its annual range relatively intact and is not yet known to have been heavily influenced by human activities that result in habitat loss or fragmentation - this is changing rapidly
We identified three distinct genetic clusters of caribou across the barren-ground caribou range: the largest cluster consisted of the continental barren-ground caribou subpopulations (BE, BAT, QAM and BEV/AH), the second cluster consisted of caribou from the Dolphin and Union subpopulation, and the third cluster was caribou from Southampton Island
Summary
Migratory barren-ground caribou (Rangifer tarandus groenlandicus) provide the opportunity to examine the genetic population structure of a large mammal that, in many instances, still has much of its annual range relatively intact and is not yet known to have been heavily influenced by human activities that result in habitat loss or fragmentation - this is changing rapidly. In North America, migratory barren-ground caribou have likely reached large effective population sizes since their rapid radiation during the early Holocene (Yannic et al, 2014b). One reason for the large population sizes of these caribou is that they occur primarily north of 60°N latitude, where agriculture and resource development have lagged behind other regions. These caribou have not yet experienced significant habitat changes interrupting their seasonal migrations and their calving and post-calving range. Describing dispersal and gene flow among these caribou will be useful for predicting future changes, such as those due to landscape alterations and warmer climates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
