Natural Resources, School of

 

Date of this Version

2000

Citation

The Journal of Wildlife Management, Vol. 64, No. 1 (Jan., 2000), pp. 11-23

Comments

This article is a U.S. government work, and is not subject to copyright in the United States.

Abstract

Loss and alteration of breeding habitat have been proposed as causes of declines in several Neotropical migrant bird populations. We conducted a 4-year study to, determine the effects of winter prescribed burning and forest thinning on breeding wood thrush (Hylocichla mustelina) populations at the Piedmont National Wildlife Refuge (PNWR) in Georgia. We estimated density, adult and juvenile survival rates, and apparent annual survival using transect surveys, radiotelemetry, and mist netting. Burning and thinning did not cause lower densities (P = 0.25); wood thrush density ranged from 0.15 to 1.30 pairs/10 ha. No radiomarked male wood thrushes (n = 68) died during the 4 years, but female weekly survival was 0.981 ? 0.014 (SE) for females (n = 63) and 0.976 ? 0.010 for juveniles (n = 38). Apparent annual adult survival was 0.579 (SE = 0.173). Thinning and prescribed burning did not reduce adult or juvenile survival during the breeding season or apparent annual adult survival. Annual population growth (X) at PNWR was 1.00.(95% confidence interval [CI] = 0.32-1.63), and the considerable uncertainty in this prediction underscores the need for long-term monitoring to effectively manage Neotropical migrants. Population growth increased on experimental compartments after the burn and thin (95% CI before = 0.91-0.97, after = 0.98-1.05), while control compartment X declined (before = 0.98-1.05, after = 0.87-0.92). We found no evidence that the current management regime at PNWR, designed to improve red-cockaded woodpecker (Picoides borealis) habitat, negatively affected wood thrushes.

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