Influence of Habitat Disturbances on Endemic Grassland Bird Distributions in Loamy Ecological Range Sites at Canadian Forces Base Suffield, Alberta

Abstract

Many grassland birds are at risk and habitat disturbance may have an important influence on the persistence of these species. Military bases provide an opportunity to examine the influence of habitat disturbance on grassland birds, whose distributions are influenced by vegetation structure. Spatial autocovariate generalized linear models were developed for four primary endemic grassland bird species from point count data collected in loamy ecological range sites during spring 2013 and 2014. These models indicated habitat disturbances influenced bird distribution, but the response differed among species. The strongest response was to fire; relative abundance of two species increased with greater fire impact while the other two decreased. A Wilcoxon Signed-Rank test of matched burned and unburned areas showed fire reduced remotely sensed grassland vegetation (p < 0.001). These results indicate disturbed and undisturbed areas provide a range of habitats suitable to the endemic grassland bird species studied.