Impacts of fire on bird populations in a fescue prairie

Abstract

Breeding bird populations were monitored for three years after an October prescribed burn in a fescue grassland near Saskatoon, Saskatchewan. Breeding populations of 12 species were recorded on a 12.9 ha burned plot and an adjacent 5.6 ha unburned plot, each with similar vegetation. The two most common species, Savannah Sparrow (Passerculus sandwichensis) and Clay-coloured Sparrow (Spizella pallida) were both adversely affected by the burn. By the third post-burn year, density of Savannah Sparrows was 68% of the value (1.70 pairs/ha) observed in the unburned area, while Clay-coloured Sparrows were only 33% of the density (1.07 pairs/ha) noted in the unburned area. Other important species, Sprague's Pipit (Anthus spragueii) and Western Meadowlark (Sturnella neglecta) were adversely affected initially by the burn but by the third year, population densities in the burned and unburned areas were comparable. Baird's Sparrow (Ammodramus bairdii) did not use the burned area in the first year, but as the grassy canopy became reestablished, the burned area was utilized at moderate densities in the second year, and in the third post-burn year densities were identical in burned and unburned ares (0.27 pairs/ha). Only the Vesper Sparrow (Pooecetes gramineus) showed a preference for the burned area in the first year after the burn.