Does Red FoxVulpes vulpesAffect Bird Species Richness and Abundance in an Agricultural Landscape?

Abstract

Abstract. The aim of the study (carried out 25 km south of Poznan, western Poland) was to determine the impact of Red Fox on bird abundance on farmland. Bird abundance was studied in the years 1999–2000 and 2005–2007 in three categories of sampling plots: 1) in small woods — with or without active fox dens, 2) along transects — starting from dens and running across arable land, and 3) around points — located at dens and far from them. Thus, variability in bird density was analyzed in relation to the presence/absence of Red Fox (in woods) and to the intensity of Red Fox penetration of crops (approximated by distance from a den). Two groups of bird species were distinguished with respect to their vulnerability to Red Fox predation pressure: 1) potential fox prey, i.e. species nesting on the ground and in low vegetation; and 2) birds not threatened by foxes, i.e. species nesting in tree holes and in tall vegetation. To investigate the relationships between bird distribution and Red Fox dens in woods, a step-...