Semester

Spring

Date of Graduation

2006

Document Type

Dissertation

Degree Type

PhD

College

Davis College of Agriculture, Natural Resources and Design

Department

Wood Science and Technology

Committee Chair

John W. Edwards.

Abstract

Ruffed Grouse (Bonasa umbellus) populations have been declining throughout the Appalachian Mountains for several decades. From 1996--2002, state natural resources agencies in the region initiated the Appalachian Cooperative Grouse Research Project (ACGRP) to investigate potential factors limiting Ruffed Grouse populations. At the onset, nest success, nest predation, and brood survival were identified as potential limiting factors, and numerous other aspects of grouse ecology (e.g., dispersal) in the Appalachians were poorly understood. Therefore, I designed my ACGRP project to examine (1) nest predation and factors that influence nest success, (2) cause-specific mortality and survival rates for chicks 2--4 days posthatch to 5 weeks posthatch, and (3) factors influencing dispersal distances, rates of movement, and risks during dispersal.;Using infrared video-surveillance systems during 2000--2001, I observed grouse nests (n = 15) in West Virginia, recording nest visitors, depredation events, and female behaviors. Incubation initiation date, clutch size, and hatching success did not differ by age (i.e., first-time breeders vs. adults). I observed 4 nest visitors during the egg-laying period, none of which removed or harmed any eggs. I observed 5 different species of nest visitor during incubation, 2 of which did not harm or remove any eggs. Nest predators included 2 raccoons (Procyon lotor), 1 black bear (Ursus americanus), and 1 long-tailed weasel (Mustela frenata). Females averaged 209 +/- 20 min on the nest per egg-laying event and I found no effect of female age, day in the nesting cycle, or age*day interaction on mean on-nest duration ratio, off-nest duration ratio, or number of egg-turnings per hour when females returned to lay an additional egg. I also found no effect of nest outcome, day in the nesting cycle, or outcome*day interaction on mean ratios females spent on or off their nests, or number of egg-turnings per hour during the egg-laying period. During incubation, I determined that on-nest ratios tended to increase through time regardless of age, off-nest ratios tended to decrease through time regardless of age, and nighttime egg turning events tended to increase through time. The number of daytime egg-turning events per hour differed between first-time breeders and adult grouse, indicating that nesting "experience" may influence daytime egg-turning behavior. I also found that both on-nest and off-nest duration ratios differed by day in the nesting cycle regardless of nest outcome; on-nest ratios tended to increase through time, whereas off-nest ratios tended to decrease through time. However, I did find that female Ruffed Grouse that lost their nest had higher on-nest ratios on the day of predation than all other days of incubation. In Ruffed Grouse, it appears likely that selection has led to incubation behaviors that favor high nest attentiveness and few foraging trips (i.e., reduced activity at the nest) to try and compensate for high levels of nest depredation. (Abstract shortened by UMI.).

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