Masters Theses

Date of Award

8-2002

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

David A. Buehler

Committee Members

Craig A. Harper, Arnold Saxton

Abstract

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.

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 < 0.05).

Early brood locations (hatch - 3 weeks) in 2001 (n = 64) had greater % ground

cover (54%, P < 0.0001), were more frequently on eastern slope aspects than northern aspects (34% of locations on east aspects, P = 0.0013), were closer to streams (301 m, P = 0.0071), and had greater densities of invertebrates in preferred orders (78 invertebrates/m2, P < 0.0001) than random locations. Brood locations in the late period (4 - 10 weeks, n = 30) had greater % ground cover (65%, P = 0.0037), lower basal area (14.5 m2/ha, P = 0.0444), greater % vertical cover (72%, P = 0.0257), and greater densities of invertebrates in preferred orders (59 invertebrates/m2, P < 0.0040) than random locations.

Broods selected 6 to 30-year-old stands (50% of locations) more frequently than random (P < 0.0001), but did not select habitat based on forest cover-type (P > 0.05).

Grouse management strategies for brood habitat should include practices that increase forb and fern ground cover during the summer months, because brood habitat may be limiting during that time. Prescribed fire and forest thinnings that allow sunlight to reach the forest floor may be useful tools in accomplishing this goal. Wildlife openings and logging roads should consist of forbs which allow chicks to move and forage efficiently while providing protective overhead cover. Forest regeneration cuts should be separated in time and space, so that a mosaic of forest age-classes is produced.

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