Egg rejection behavior does not explain the lack of cowbird parasitism on an eastern North American population of Red-winged Blackbirds

Table 1 Average Brown-headed Cowbird parasitism frequency on Red-winged Blackbird nests for three regions across North America based on a review of the literature

Region	Nests examined	Nests parasitized	% Parasitized	Range (%)
West	6658	368	5.5	0.0–12.5
Central	11,077	1888	17.0	0.0–100
East	10,798	186	1.7	0.0–8.3

Data are compiled from studies in Appendix. See Appendix for definitions of the three regions

ISSN: 2053-7166