Brown-headed Cowbird (Molothrus ater) Science Article 2 abstract In four large aviaries, we studied social assortment and reproductive behaviour of female brown-headedcowbirds housed with males differing in age class and in corresponding levels of intrasexual interaction.Juvenile and adult females resided with either (1) adult males, (2) juvenile males, (3) adult and juvenilemales, or (4) no […]
Tag: Molothrus ater
A future cost of misdirected parental care for brood parasitic young?
Brown-headed Cowbird (Molothrus ater) Science Article 1 abstract Parental care is advantageous because it typically increases the survival ofgenetically related young. In contrast, parental care given to unrelated young incurs no benefit.A further cost of parental investment is that it reduces the future reproductive potential of thecaregiver. I examined whether eastern phoebes’ Sayornis phoebe future […]
Variation in growth of Brown-headed Cowbird(Molothrus ater) nestlings and energetic impactson their host parents
Brown-headed Cowbird (Molothrus ater) Science Article 6 abstract I tested several hypotheses about the plasticity of avian growth by comparing growth of Brown-headedCowbird (Molothrus ater) nestlings in 20 different host species. Growth of cowbird nestlings was not strongly correlatedwith host adult mass and nearly all hosts were able to provision cowbirds with enough food to […]
Retaliatory mafia behavior by a parasitic cowbirdfavors host acceptance of parasitic eggs
Brown-headed Cowbird (Molothrus ater) Science Article 12 abstract Why do many hosts accept costly avian brood parasitism evenwhen parasitic eggs and nestlings differ dramatically in appearancefrom their own? Scientists argue that evolutionary lag orequilibrium can explain this evolutionary enigma. Few, however,consider the potential of parasitic birds to enforce acceptance bydestroying eggs or nestlings of hosts […]
Host use strategies of individual female brown-headed cowbirdsMolothrus ater in a diverse avian community
Brown-headed Cowbird (Molothrus ater) Science Article 7 abstract Although it is well established that brown-headed cowbirds Molothrus ater are hostgeneralists, the parasitism strategies of individual females are not well documented.Here we use microsatellite genotyping to characterize host use by individual femalecowbirds. Of 205 offspring sampled at a site in northeastern Illinois during onebreeding season, we […]
Brown-headed Cowbird and their Impact on Songbirds
Brown-headed Cowbird (Molothrus ater) Science Article 17 abstract In recent decades, many environmental organizations, conservationists, and biologists have argued that the Brown-headed cowbirds are a major threat to migratory songbirds population. Therefore, I discuss broad aspects about the Brown-headed cowbirds, including nesting andbreeding ranges, nurture, and scientific classification. Jabber M. Al-jabber, unknown Download article download […]
Female brown-headed cowbirds’ (Molothrus ater)social assortment changes in response to male song:a potential source of public information
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 […]
Developmental Origins of Sociality in Brown-Headed Cowbirds(Molothrus ater)
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, […]
Demography, mating system and reproductive success ofthe Brown-headed Cowbird (Molothrus ater) at Delta Marsh,Manitoba
Brown-headed Cowbird (Molothrus ater) Science Article 13 abstract The Brown-headed Cowbird (Molothrus ater) is anative North American icterid and the most commonobligate interspecific brood parasite in North America.Brood parasites lay their eggs in the nests of other birdspecies and all parental care, including incubation andfeeding is provided by the host species. The matingsystem of the […]
The cultural transmission of courtship patterns in cowbirds,Molothrus ater
Brown-headed Cowbird (Molothrus ater) Science Article 4 abstract In this study, I tested whether the courtship behaviours that facilitate patterns of assortative pairing andmating could be culturally transmitted across generations of brown-headed cowbirds. In an earlier study,I housed a first generation of young South Dakota cowbirds in one of two cultural backgrounds: (1) withadult social […]