Short-term response of wetland birds to prescribed burning in Rainwater Basin wetlands

Abstract

Prescribed burning is often used in wetlands to remove plant litter, decrease woody or invasive species, and increase use by wetland birds. However, little is known about the within-season, short-term response of wetland birds to prescribed burning, especially during spring migration. We surveyed use of 19 burned and 19 unburned (reference) wetlands by migratory birds in the Rainwater Basin region of Nebraska, USA during three spring migrations, 2002-2004. We calculated the change in avian abundance and species richness, as well as generating the Sorenson's similarity index for burned and reference wetlands in the weeks immediately before and after burning. We compared Sorenson's index values and percent change in abundance and species richness between burned and reference wetlands using an analysis of covariance with week and wetland area as covariates to account for migration chronology and differences in the area of experimental units. Following removal of effects due to wetland area and week, burning had no effect on the percent change in avian abundance and species richness. Sorenson's index also did not differ between burned and reference wetlands. Prescribed burning did not improve use of wetlands by migratory birds in the short term. Understanding the immediate and long-term effects of prescribed burning on migratory avian abundance, species richness, and community composition is imperative for management decisions.