Temporal patterns of host availability, brown-headed cowbird brood parasitism, and parasite egg mass

  title={Temporal patterns of host availability, brown-headed cowbird brood parasitism, and parasite egg mass},
  author={Bill M. Strausberger},
  • B. Strausberger
  • Published 1 August 1998
  • Environmental Science, Biology
  • Oecologia
Abstract I studied relationships between temporal patterns of host availability, brood parasitism, and egg mass for the parasitic brown-headed cowbird (Molothrus ater). At a study site consisting largely of edge habitat in north-eastern Illinois, I found 834 bird nests from 27 species. A total of 407 cowbird eggs and nestlings were found in these nests over three laying seasons. Nearly all (n= 379; 93%) were found in the nests of seven host species. For these species and all taken together… 
Community-level patterns of parasitism: Use of three common hosts by a brood parasitic bird, the brown-headed cowbird1
It is suggested that host quality may explain the higher than expected use of song sparrows and factors that alter the relative availability of hosts, such as host breeding synchrony, may modify the parasitism levels experienced by different hosts.
Community-level patterns of population recruitment in a generalist avian brood parasite, the brown-headed cowbird
Cowbird recruitment was diverse with respect to hosts but was less evenly distributed across the host community than was cowbird egg investment, which may be associated with the larger body size of tanagers relative to other hosts.
Community-Level Patterns of Host Use by the Brown-Headed Cowbird (Molothrus ater), a Generalist Brood Parasite
The results indicate that cowbirds in northeast Kansas differentially parasitize hosts, that most cowbird eggs are laid in the nests of a small number of host species, and that the Dickcissel appears to be preferred over other hosts.
High Levels of Relatedness between Brown-Headed Cowbird (Molothrus ater) Nestmates in a Heavily Parasitized Host Community
Evidence that laying decisions of female cowbirds were constrained is found, which suggests that heavy parasitism levels were due to a high degree of competition for host nests.
Host use and fecundity of individual female brown-headed cowbirds
The results suggest that female laying behaviour lies on a gradient between the two extreme categories of pure ‘shotgun’ or ‘host selection’ laying behaviours, and females may optimize their reproductive effort by varying their behaviours as environmental conditions dictate.
Rates of parasitism, but not allocation of egg resources, vary among and within hosts of a generalist avian brood parasite
It is found that the probability of being parasitized by cowbirds, controlling for host status as a cowbird egg accepter or rejecter and ordinal date, varied significantly among host species, indicating an apparent preference for some hosts.
Site selection and repeatability in Brown-Headed Cowbird (Molothrus ater) parasitism of Eastern Phoebe (Sayornis phoebe) nests
Observations on patterns of Brown-headed Cowbird parasitism on Eastern Phoebes (Sayornis phoebe) across 2 years suggested that parasitism occurred at above chance levels during the first rather than the second nesting attempts and at nests located under eaves rather than bridges.
Molecular tracking of individual host use in the Shiny Cowbird – a generalist brood parasite
Overall, female shiny cowbirds use a spatially structured and host species specific approach for parasitism, but they do so nonexclusively, resulting in both detectable levels of multiple parasitism and generalism at the level of individual parasites.
Genetic elucidation of host use by individual sympatric bronzed cowbirds (Molothrus aeneus) and brown-headed cowbirds (M. ater)
It was found that each species of cowbird used primarily four host species, with minimal overlap in the species used, yet at least some individuals acted as generalists.
Shiny Cowbird parasitism of a low quality host: effect of host traits on a parasite's reproductive success
The reproductive success of parasitic cowbirds (Molothrus spp.) varies among host species and is influenced by the degree of synchronization in timing of egg laying, the duration of parasite and host


Shiny cowbirds follow the ‘shotgun’ strategy of brood parasitism
  • G. Kattan
  • Biology, Environmental Science
    Animal Behaviour
  • 1997
Abstract Brood parasitic cowbirds, Molothrus spp., should lay their eggs in host nests at a time that maximizes both the probability of acceptance by the host and the chances of survival for the
Removal of Yellow Warbler Eggs in Association with Cowbird Parasitism
  • S. Sealy
  • Biology, Environmental Science
  • 1992
The results suggest that cowbirds can remove at least two eggs without risking desertion by the warblers, as predicted by the "host deception" hypothesis.
It is concluded that the use of eggs as food may not be the primary cause of egg removal by Brown-headed Cowbirds, and six explanations are offered to account for the failure of cowbirds to eat many eggs.
Brood parasitism of the shiny cowbird, Molothrus bonariensis, on the brown-and-yellow marshbird, Pseudoleistes virescens
Shiny cowbird chicks were not outcompeted for food although they are smaller than the host chicks, and Artificial parasitism experiments showed that the host rejected the cowbird white eggs.
Temporal and age-related variation in the laying rate of the parasitic brown-headed cowbird in the eastern Sierra Nevada, California
Spatial, temporal, and age-related variation in the laying rate of female brown-headed cowbirds in Mono Co., California was assessed by determining the proportions of samples of live-trapped females
The Breeding Season of a Parasitic Bird, the Brown-Headed Cowbird, in Central California
The breeding seasons of birds are usually timed so that the young are reared during a period of abundant food, but birds that do not feed their young but instead lay their eggs in nests of other species must generally lay when their foster species do.
Population Dynamics of Avian Brood Parasitism
It is suggested that females of many parasitized species must renest several times within a season in order to replace themselves, and several species are in danger of extirpation as a result of brood parasitism by cowbirds, which are increasing in population and have expanded their ranges and come into contact with many species that have not evolved a resistance to brood parasites.
The effect of magpie breeding density and synchrony on brood parasitism by great spotted Cuckoos
Results show that increased proximity to other nests and specially laying synchrony both reduced the probability of being parasitized, and magpies breeding synchronously in dense plots may experience an indirect advantage against brood parasitism with respect to low density, low synchrony plots.
Laying eggs in others' nests: Intraspecific brood parasitism in birds.
Inter- and intraspecific relationships between egg size and clutch size in waterfowl
The results suggest that the widely accepted egg-production hypothesis may be considerably overemphasized and the predicted inverse relationship between egg size and clutch size within and among species of waterfowl.