Ruffed Grouse Nesting Ecology and Brood Habitat in Western North Carolina
Author | : |
Publisher | : |
Total Pages | : |
Release | : 2002 |
ISBN-10 | : OCLC:50856311 |
ISBN-13 | : |
Rating | : 4/5 (11 Downloads) |
Book excerpt: Ruffed grouse (Bonasa umbellus) population densities are lower in the southern Appalachians compared to more northern parts of grouse range. Southern forests lack an aspen (Populus spp.) forest component, which provides year-round habitat in the North. The absence of aspen and low productivity have been cited as possible causes for low grouse densities in the southern Appalachians. In addition, habitat quality in the eastern United States may be decreasing as forests mature. These factors contribute to concerns that the region may be experiencing long-term ruffed grouse population declines. Productivity and breeding habitat must be characterized to foster better forest management strategies and ensure viable ruffed grouse populations in the southern Appalachians. The objective of this study was to quantify productivity and characterize habitat at nest and brood locations in the Nantahala National Forest, North Carolina. Radio-collared hens were monitored in April-July 2000 and 2001 to determine nesting rate, clutch size, nesting chronology, and nest survival. Habitat characteristics were measured at nests (n=19), and brood locations (n=115) for 14 hens. Invertebrate samples (n=932) were taken at each brood and random location during the first 6 weeks post-hatch to determine food availability for young ruffed grouse chicks. Nest and brood locations were paired with random locations to compare used versus available habitat. Mean incubation initiation dates varied between years (P=0.0050) and ranged from 10 April to 29 April. Hen incubation rate (84%), Mayfield nest survival (76%), mean clutch size (10.1 eggs/nest), and egg hatching success (95%) did not differ between years or age classes (P>0.05). Hens selected nest locations with more dense vertical cover (83%) than random. No chicks (n=48) survived past 4 weeks post-hatch (n=5 broods) in 2000. In contrast, all broods (n=9) had at least one chick survive through the entire brooding season in 2001. Brood habitat selection differed between years (P