Fencerows as habitat for birds in an agricultural landscape in central Alberta, Canada

Abstract

Fencerows (strips of trees along field edges) are common in agricultural landscapes and may represent valuable habitat for forest birds in areas where woodland is scarce. We examined the relationship between avian presence (species richness, territory density, and abundance) in 26 fencerows and vegetation structure in the fencerows and forest cover in the adjacent landscape in central Alberta, Canada. Species richness was positively related to fencerow area, but not to other vegetation or landscape characteristics. In contrast, territory density was highest in smaller fencerows with high tree diversity and those with a low amount of forest cover in the surrounding landscape. Redundancy analysis indicated that abundance of 16 common species was associated with vegetation in the fencerow and/or forest cover in the surroundings. Species composition in seventeen woodlots in the area was compared with fencerow species composition. Species recorded in fencerows represented 50% of the regional species pool found in woodlots. Fencerows had mainly edge species, no interior forest species, but harbored two species (Vesper Sparrow and Eastern Kingbird) not found in woodlots. Although we advocate the retention and even restoration of fencerows, this cannot be done to the exclusion of retaining large blocks of forest in the landscape for interior forest species.