Planet of Birds

Brown-headed Cowbird (Molothrus ater) Science Article 5 abstract In many species, females’ behavior appears to be influenced by that of other females, particularly regarding mate choice. Females theoretically can reduce the costs associated with independent male assessment by observing conspecifics. Studies of brown-headed cowbirds suggest that females pay attention to other females’ behavior. Group-housed females […]

Brown-headed Cowbird (Molothrus ater) Science Article 19 abstract Five variables were studied relating to the emergence of sociality in hand-reared cowbirds (Molothrus ater): proximity, sex assortment, reactions to adults, head-down displays, and vocalizations. The authors were especially interested in female sociality because adult female birds influence male courtship, song content, and use through proximity, attention, […]

Brown-headed Cowbird (Molothrus ater) Science Article 3 abstract Previous work has shown that captive female cowbirds, Molothrus ater, can influence the outcome of malesong development by affecting retention or deletion of song elements and by stimulating improvization.Here we looked for evidence of female influence during the process of learning, as males progress fromsubsong to plastic […]

Brown-headed Cowbird (Molothrus ater) Science Article 11 abstract We characterized several equivocal aspects of the breeding biology of the broodparasitic Brown-headed Cowbird (Molothrus ater) at a study site in northeastern Illinois. Atotal of 175 offspring and a partial sample of parents were sampled and genotyped at sixmicrosatellite loci. A combination of sibling-group and parentage assignment […]

Brown-headed Cowbird (Molothrus ater) Science Article 18 abstract The breeding seasons of birds are usually timed so that the young are reared during aperiod of abundant food. At high latitudes nearly all small birds may nest within a weekor two of each other. In warmer temperate climates where plants grow and insects areactive for several […]

Brown-headed Cowbird (Molothrus ater) Science Article 9 abstract From May through July, 1993-1998 and 2001, effects of Brown-headed Cowbird (Molothrus ater) parasitism on 36 Warbling Vireo (Vireo gilvus) nests were documented in southwest Colorado. Overall parasitism was 75.0% and was the major source of nest failure. Among vireo nests that were not depredated, a significantly […]

Brown-headed Cowbird (Molothrus ater) Science Article 20 abstract Females of the brood-parasitic brown-headed cowbird (Molothrus ater) search for host nests in which to lay their eggs. Females normally return to lay a singe egg from one to several days after first locating a potential host nest and lay up to 40 eggs in a breeding […]

Brown-headed Cowbird (Molothrus ater) Science Article 16 abstract Brown-headed Cowbirds (Molothrus ater) have parasitized at least 220 species of birds, of DONALD H. WOLFE, Wilson Bull., 106(4), 1994, pp. 764-766 Download article download full text (pdf)

Brown-headed Cowbird (Molothrus ater) Science Article 15 abstract I studied patterns of cowbird parasitism and responses to this parasitism by Bell’s Vireos (Vireo bellii) in Kansas. Bell’s Vireos abandoned parasitized nests at a significantly higher rate than unparasitized nests. Lower probability of brood parasitism later in the season may help make abandonment followed by renesting […]

Brown-headed Cowbird (Molothrus ater) Science Article 8 abstract A removal experiment was conducted to measure how much and by whatmechanisms brood parasitic Brown-headed Cowbirds (Molothrus ater) cause nest failures in acommonly used host, the Song Sparrow (Melospiza melodia). When numbers of female cowbirdswere reduced experimentally, nest failures fell from 65.0% (n = 663 nests) to […]