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Nesting Ecology, Chick Survival, and Juvenile Dispersal of Ruffed Grouse (Bonasa umbellus) in the Appalachian Mountains Brian W. Smith 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 eggturnings 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 egglaying 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. Advancements in transmitter technology (e.g., miniaturization, attachment methods) have allowed researchers to examine survival and causes of mortality in precocial chicks while also minimizing captureand transmitter-related stress. Therefore, I placed collar-type transmitters on grouse chicks 2–4 days posthatch to determine fates and survival rates for chicks at 3 study areas in the Appalachian Mountains during their first 35 days posthatch. During 2000–2002, I captured 177 chicks from 48 broods, and equipped 139 chicks with collar-type transmitters. Overall, I determined fates of 118 of 139 (85%) radio-collared chicks; 110 (79%) succumbed to some form of mortality. Exposure (44%) and predation (44%) accounted for most known mortalities. Mammalian (38%) and avian (33%) predation rates were similar; however, a substantial number of predation events were classified as “unknown” (29%). Of the 118 chicks of known fate, 8 (6%) survived to 35 days posthatch and I lost contact with 21 (15%) others. Entire brood loss before 35 days posthatch was fairly common (29%). Survival to 35 days posthatch ranged from 0.06 in 2002 to 0.19 in 2001 and from 0.09–0.13 across the 3 study areas. Overall, survival of Ruffed Grouse chicks in the Appalachian Mountains is low during the first few weeks of life, but major causes of mortality varies annually and appears to vary with chick age. A common assumption about dispersing animals is that they experience a higher rate of mortality than more sedentary animals through inherent risks associated with unfamiliar areas, energetic stress, or increased predation rates. Few studies exist describing dispersal patterns of juvenile Ruffed Grouse (Bonasa umbellus) or factors influencing mortality risks in the Appalachian Mountains. I examined effects of forest type (mixed mesophytic or oak-hickory), hard mast production, grouse gender, and timing of dispersal on dispersal distances and movement rates, or if grouse did not disperse, on the number and average distance of forays outside of their 75% fixed kernel home range. I also constructed Cox’s proportional hazards models to determine if the risk of mortality for juvenile grouse was associated with various rates of movement, familiarity with a site, gender, hard mast production, or forest type. Timing of dispersal influenced dispersal distance, with fall dispersers moving farther on average (2525 ± 162 m) than winter transients (1424 ± 300 m). Interestingly, males actually traveled farther on average during winter transience than did females. Individual effects of both mast index and forest type approached significance, and the parameter estimate for mast index indicated that grouse disperse farther as hard mast production increased. Average daily movement rates for all grouse were greater in fall than both overall and winter rates, but no variables of interest seemed to influence foray search frequency or distance for grouse that did not disperse. Forest type influenced mortality risks in Ruffed Grouse; risk was lower for birds on mixed mesophytic sites compared to those on oak-hickory sites. Mortality risk also decreased for grouse as familiarity with a site increased for two periods of movement I measured. Dispersal patterns of Ruffed Grouse in the Appalachian Mountains appear fairly similar to grouse elsewhere throughout their range, but mortality risks associated with dispersal movements may be quite different. The influence of forest type and site familiarity on Ruffed Grouse mortality may be specific to the Appalachian Mountains given the drastic differences in habitats compared to other parts of their range.

Nesting ecology, chick survival, and juvenile dispersal of Ruffed Grouse (Bonasa umbellus) in the Appalachian Mountains