Contents 



Page 



Preface vii 



A comment on cowbird parasitism 1 



Brown-headed cowbird 5 



Discussion 5 



Frequency of host selection 6 



Changes in host selection 9 



Intensity of parasitism of frequent hosts 12 



Breeding success of host and parasite 15 



Hatching potential of host species 21 



Mutual effect of parasite and host on egg production 22 



Duration of parasite's interest in host nests 25 



Interspecific preening invitational behavior 29 



Foster parent-offspring relationship 31 



Reactions of host to parasitism 33 



Hosts known to have reared young of parasite 37 



Hosts of the brown-headed cowbird 41 



Bronzed cowbird 173 



Discussion 173 



Hosts of the bronzed cowbird 175 



Shiny cowbird 189 



Discussion 189 



Imperfections in host relations 189 



Frequency of host selection 192 



Destruction of host eggs by parasite 196 



Hosts known to have reared young of the parasite 196 



Hosts of the shiny cowbird 199 



Screaming cowbird 216 



Giant cowbird 218 



Literature cited 223 



Index 253 



V 



