Date of Award

12-2010

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Jeffery L. Larkin, Ph.D.

Second Advisor

Joseph E. Duchamp, Ph.D.

Third Advisor

Shundong Bi, Ph.D.

Fourth Advisor

Tim Nuttle, Ph.D.

Abstract

Allegheny woodrat (Neotoma magister) populations are declining across the northern portion of their range. Multiple hypotheses have been proposed to explain these declines; 1) habitat fragmentation; 2) disease; and 3) food limitations. The purpose of this study was to relate demographic parameters to habitat characteristics at study areas. From May 2007 - July 2009, I captured 262 Allegheny woodrats on the Chestnut Ridge in Westmoreland Co, Pennsylvania. I estimated population demographics using capture mark recapture methods. Overall detection probability was high (0.90 - 0.96). Over winter survival was higher for females (=x 0.49) than males (=x 0.29). Survival was lower at sites with high levels of human disturbance (=x 0.51) than other study areas (=x 0.63; β = -0.855, SE = 0.325, RI = 1.00) and for winter 2008-09 (=x0.26) than other seasons (=x 0.70; β = -1.989, SE = 0.382, RI = 1.00). Based on linear regression models survival was higher at sites with greater hard mast tree diversity ( β= 0.115, SE = 0.029, RI = 1.00) and lower at sites with greater soft mast tree diversity (β = -0.019, SE = 0.026, RI = 0.44), and pole timber density (β = -0.110, SE = 0.030, RI = 1.00). Fecundity was higher at sites with increased pole timber density (β = 0.433, SE = 0.115, RI = 1.00) and higher disturbance (β = -0.081, SE = 0.021, RI = 1.00) and lower at sites with increased leaf tree diversity (β = -0.216, SE = 0.054, RI = 1.00). Adult woodrat density (=x 2.83) was lower with increased pole timber density ( β = -0.098, SE = 0.078, RI = 0.71) and higher with increased slope, on south-facing slopes and greater other food tree diversity (β = -0.141, SE = 0.047, RI = 1.00). The persistence of Allegheny woodrat populations is currently constrained by unknown factors. Maintaining high quality habitat, high diversity of hard mast and low disturbance should be a species priority. Incorporation of my results into recovery and management plans may aid in the maintenance of habitat optimal for the survival and persistence of Allegheny woodrat.

Share

COinS