PARENT SESSION
Contributed Oral Session 88: Mammal Ecology: Habitat and Movement
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 524 A, Level 5, Palais des congrès de Montréal
The influence of habitat fragmentation on a mesocarnivor.
Ray, Robin*,1, Swanson, Dr. Bradley1, 1 Central Michigan University, Mt. Pleasant, MI, USA
ABSTRACT- Increased genetic isolation, due to the increasing human population, creates deleterious consequences such as decreased genetic variation and increased inbreeding. This study examined how habitat fragmentation, as indexed by roads, impacts gene flow between and the number of badger (Taxidea taxus) populations in the Upper Peninsula (UP) and Lower Peninsula (LP) of Michigan. The degree of fragmentation in each peninsula, as defined by roads, was calculated in ArcView GIS 3.2a. All counties that allow badger hunting and trapping were included in the analyses. This includes zone 1 in the eastern UP (west of highway 13), zone 2 in the northern portion of the LP, and zone 3 in the southern portion of the LP. Trapping season for zones 1 and 2 is October 15-November 14 and November 14-March 1 for zone 3. The bag limit is one per person in all zones. Road coverage and density were determined using Census 2000 TIGER/Line Data. The degree of fragmentation was defined by total road density (km/km2) and the creation of patches by these road types, which included patch density (number/100 km2) and patch size (km2). Patches were defined as any polygon created by the intersection of trunkline roads. There was a significant difference in the level of fragmentation in the upper peninsula and lower peninsula of Michigan. Total road density in the UP (0.070 km/km2) was lower than in the LP (0.12 km/km2). This is similar to patch density where the UP (0.090 patches/100 km2) was lower than the LP (0.18 patches/100 km2). A significant difference in the median patch size was found between the UP (935.5 km2) and the LP (467.2 km2) (Mann-Whitney Test; W = 1850.0; P = 0.002). DNA was extracted from badger tissue samples and analyzed on an automated DNA sequencer for ten microsatellite loci using Genescan and Genotyper. The program STRUCTURE determined the most likely number of badger populations in Michigan, which was two. Results showed little genetic isolation and significant interpopulation dispersal of badgers among the LP and isolation between the UP and LP. The Michigan badger populations seem genetically healthy with an allelic diversity (A=7) and average heterozygosity (H=0.36) in the UP and allelelic diversity (A=7) and average heterozygosity (H=0.41) in the LP.
Key words: isolation, fragmentation, taxidea taxus