Northern Shrike (Lanius excubitor) Science Article 6
The great grey shrike, Lanius excubitor, is known to be a raptor-like passerine. In addition to invertebrate prey, its diet also consists of vertebrates, including small birds. We examined the effect of presence of the great grey shrike on the breeding assemblages of small passerine birds in an intensively farmed landscape in western Poland. Line transects were used for bird censuses. Birds were counted at 29 treatment transects (length 500 m, width 100 m), located within shrike territory, as well as 29 control transects, situated > 800 m from the nearest shrike nest. Treatment and control transects did not differ with respect to the habitat composition. We did not detect any difference between territories and controls regarding either numbers of recorded bird species, or pairs. However, the vicinity of shrike nests negatively affected the total density of the skylark Alauda arvensis, the most abundant bird species and important item of shrike bird prey, and the whinchat Saxicola rubetra. The results indicate that the presence of the great grey shrike selectively affects species of breeding bird communities.
Hromada, M., Tryjanowski, P. & Antczak, M. 2002, Ann. Zool. Fennici 39: 125-130