Demography and genetic structure of an Allegheny woodrat population in northcentral West Virginia.

摘要

The Allegheny woodrat (Neotoma magister) occurs throughout the Appalachian Mountains forming isolated colonies in rock outcrops, cliffs, and caves. In the past 20--30 years, populations along the northern and western peripheries of the range have experienced drastic declines. There have been suggested reasons for this decline but a lack of long-term data has prevented application of specific management actions. In recent years, there has been more insight into population structure, gene flow, and relatedness among colonies. The objectives of my study were to examine these factors at a localized level to further assist with future management decisions.; Using data collected over the last nine years, population trends were examined at three study areas in northcentral West Virginia along the western ridge of the central Appalachian Mountains. Relations to temperature and precipitation along with mast production were analyzed to determine if environmental variables are a factor impacting the population. Results suggest that there has been a decrease in the overall population with the adult female segment most affected. Juvenile capture rate was negatively correlated with winter temperature supporting the hypothesis that the severity of winters is a factor affecting the northern populations.; Geographic genetic variation was previously examined throughout the entire Allegheny woodrat distribution. The current research analyzed genetic differentiation at a smaller scale to determine if analysis of a larger proportion of the population would result in further population structure. Movements within and among specific outcrops suggest that outcrops function as breeding assemblages but that the Cheat River does not limit movement between the study areas. Results suggest that the regional populations are less differentiated than previously assumed and management decisions should be applied to a wider spatial scale to increase the genetic variation among the subpopulations. To assign parentage and kinship, likelihood based approaches were used. Results support field observations of one to four young per litter and greater juvenile dispersal in male woodrats.