Immobilization of Small Mammals and Occupancy, Seasonal Food Habits, and Parasites of Allegheny Woodrats in the Cumberland Mountains, Tennessee

Author

William Teague Parker, University of Tennessee - Knoxville

Date of Award

8-2006

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

Lisa Muller

Committee Members

Reid Gerhardt, Edward Ramsay, Arnold Saxton

Abstract

Allegheny woodrats (Neotoma magister) occur throughout the Appalachians north of theTennessee River. Declines have occurred in the northern and western parts of their range, prompting the need for more information about the species in areas where they are rare. The purpose of this study was to gain more information on the Allegheny woodrat in the Cumberland Mountains of Tennessee. The main objectives were to (1) evaluate isoflurane anesthesia to immobilize woodrats and other small mammals for biological sample collection and (2) determine percent occupancy, food habits, and external parasite species of Allegheny woodrats at likely candidate sites in easternTennessee.

I evaluated a chamber and nose cone method of isoflurane delivery for immobilizing eastern gray squirrels (Sciurus carolinensis; summer n = 43, winter n = 48) and Allegheny woodrats (summer n = 24, winter n = 13) respectively. Time to induction for squirrels did not differ between summer (3.24 min) and winter (3.13 min) or by sex. Squirrels awoke more quickly in the summer (1.47 min) than in the winter (3.66 min) after removal of the nose cone and their pulse was higher in the winter, whereas body temperature and respiration were lower. I administered the nose cone for 0.5 min for all woodrats since it was not possible to determine induction time because the animals were being manually restrained. There were no differences by season or sex for timing of effects or physiological parameters in Allegheny woodrats. Woodrats awoke in 4.22 min in the summer and 4.06 min in the winter following the final dose of isoflurane. Both methods resulted in rapid induction, quick recovery times, and acceptable physiological parameters in both summer and winter.

Data for occupancy, food habits, and external parasites for Allegheny woodrats were collected from November 2003 to August 2005 in Royal Blue Wildlife Management Area (RBWMA) andBigSouthForkNationalRiverand Recreation Area (BSFNRRA),Tennessee,USA. We determined if food availability including percent forbs (FORB) and number of mast producing trees (MAST), trap effort measured by the number of traps (N_TRAP), or location of trapping (AREA) explained detection probability (p) while occupancy (ψ) was kept constant. I evaluated the following habitat variables for their effect on occupancy: FORB (determine if woodrats preferred areas with green forage over habitats without green forage), MAST (evaluate preference of hard mast crops during the winter and habitat selection of hard mast producing trees), AREA (geographic location), and the combination of FORB and MAST (determine if woodrats occupied areas with both green vegetation and hard mast over areas with only one or none of these food items). Site occupancy models calculated from presence-apparent absence data indicated detection probabilities were best predicted by the two areas (AREA). The detection probabilities obtained from model averaging were p = 0.49 (SE = 0.13) and 0.74 (SE = 0.07) for BSFNRRA and RBWMA, respectively. Using detection probabilities explained by AREA, model selection results suggested that occupancy was constant for selected habitat variables examined. The model constraining occupancy as a function of FORB also seemed useful for model inference but the slope of this function bounded 0, indicating low predictive value. Using model averaging, the proportion of the trapping locations occupied by woodrats was 0.79 (SE = 0.12 SE) and 0.79 (SE = 0.13) for RBWMA and BSFNRRA, respectively.

I also described food habits for the summer (n = 14) and winter (n = 13) seasons in Tennessee using microhistological analysis of fecal material. The main food types in the summer were forbs, shrubs, fungus, and soft mast. The winter diet was primarily composed of fungus, forbs, shrubs, and hard mast. External parasites were collected from 26 Allegheny woodrats and included 2 woodrat fleas (Epitedia cavernicola), 63 of the woodrat specific flea Orchopeas pennsylvanicus, and 5 female woodrat ticks (Ixodes woodi).

Recommended Citation

Parker, William Teague, "Immobilization of Small Mammals and Occupancy, Seasonal Food Habits, and Parasites of Allegheny Woodrats in the Cumberland Mountains, Tennessee. " Master's Thesis, University of Tennessee, 2006.
https://trace.tennessee.edu/utk_gradthes/1762