@article {KNZ001591,
	title = {The exaggerated begging behaviour of an obligate avian brood parasite is shared with a nonparasitic close relative},
	journal = {Animal Behaviour},
	volume = {86},
	year = {2013},
	pages = {529 -536},
	abstract = {Offspring signalling models predict that the begging displays of obligate brood parasites are more intense than nonparasitic species because parasitic young are never reared by their genetic parents and often compete against unrelated host young during development. The brown-headed cowbird, Molothrus ater, has been described as having exaggerated begging relative to nonparasitic species, but an effective test of this idea is lacking because previous studies have not controlled for evolutionary history while simultaneously standardizing rearing conditions. We quantified the begging intensity of cowbirds and the closely related, nonparasitic red-winged blackbird, Agelaius phoeniceus, when both species experienced identical rearing conditions in two distinct nest environments: reared alone by a small cowbird host, or reared with two host young by a moderate-sized cowbird host. Against theoretical predictions, we found that in both nest environments four components of the cowbird begging display were similar to (or less intense than) blackbird begging displays (i.e. latency to beg, begging score, call rate and call amplitude) when nestlings were tested across a gradient of short-term need. Our results provide the first experimental evidence that a closely related, yet nonparasitic, species shares an exaggerated begging display with a brood-parasitic species when reared under conditions typically experienced by parasitic offspring. We discuss three nonexclusive explanations for our findings: (1) relatedness among cowbird nestmates reduced cowbird begging intensity (kin selection hypothesis), (2) reduced body condition of blackbirds elevated their begging intensity (body condition hypothesis) and (3) intense competition in blackbird nest environments led to increased blackbird begging intensity (competitive environment hypothesis).},
	keywords = {LTER-KNZ, Agelaius phoeniceus, begging, brood parasitism, brown-headed cowbird, Molothrus ater, offspring signalling, red-winged blackbird},
	doi = {10.1016/j.anbehav.2013.06.004},
	url = {http://dx.doi.org/10.1016/j.anbehav.2013.06.004},
	author = {Rivers, J.W. and M.A. Blundell and Loughin, T.M. and Peer, B.D. and Rothstein, S.I.}
}
@article {KNZ001596,
	title = {Brown-headed cowbird nestlings influence nestmate begging, but not parental feeding, in hosts of three distinct sizes},
	journal = {Animal Behaviour},
	volume = {79},
	year = {2010},
	pages = {107 -116},
	abstract = {<p>Avian brood parasites typically depress the fitness of their hosts by reducing the number of host offspring produced, yet little is known about how parasitic nestlings influence the behaviour of host parents and host offspring. In this study, we used three hosts of the brown-headed cowbird, Molothrus ater, that varied in size (i.e. smaller, similar to and larger than cowbirds of a given age) to determine whether parasitic nestlings altered patterns of food provisioning by host parents and begging by host young under field conditions. Adult provisioning did not change in the presence of a cowbird but instead was influenced by feeding treatment and host size. In parasitized broods where nestlings differed in size (i.e. the small and large hosts), the larger nestling received the majority of food brought to the nest, regardless of whether it was the cowbird or host nestling. In contrast, similar-sized host nestlings received a similar amount of food in parasitized and unparasitized host broods. Relative to unparasitized broods, the presence of a cowbird led to increased begging intensity by the small host, had no clear effect on begging behaviour of the intermediate-sized host, and reduced begging intensity of the large host. Taken together, these results suggest the presence of a cowbird did not lead to changes in provisioning behaviour in parents, and the extent to which cowbirds influenced host begging behaviour depended on the size of the host.</p>},
	keywords = {LTER-KNZ, begging; brood parasitism, brown-headed cowbird, host{\textendash}parasite interaction, Molothrus ater, offspring solicitation, parent feeding, provisioning behaviour},
	doi = {10.1016/j.anbehav.2009.10.009},
	url = {https://www.sciencedirect.com/science/article/pii/S0003347209004588?via\%3Dihub},
	author = {Rivers, J.W. and Loughin, T.M. and Rothstein, S.I.}
}
@article {KNZ001316,
	title = {Community-level patterns of host use by the Brown-headed Cowbird (Molothrus ater), a generalist brood parasite},
	journal = {Auk},
	volume = {127},
	year = {2010},
	pages = {263 -273},
	abstract = {<p>Quantifying community-level host use by generalist brood parasites is important because it provides a measure of the resources that parasites need for reproduction. During the 2002\&ndash;2007 breeding seasons, we quantified host use by the Brown-headed Cowbird (Molothrus ater) at Konza Prairie Biological Station in northeast Kansas. Overall, 54.4\% of nests (n = 2,621) of 22 passerine host species that typically accept parasitic eggs were parasitized, and parasitized nests contained an average of 1.9 \&plusmn; 1.03 (SD) Brown-headed Cowbird eggs, nestlings, or both. Multiple parasitism was common on the study site in all years: 55.7\% of parasitized nests (n = 1,425) received \&ge;2 Brown-headed Cowbird eggs. The Bell\&$\#$39;s Vireo (Vireo bellii; 70.5\%) and the Dickcissel (Spiza americana; 69.6\%) were parasitized at a significantly greater rate than the Red-winged Blackbird (Agelaius phoeniceus, 21.9\%); collectively, these three species represented 85.8\% of potential host nests found in all years. The host preference of Brown-headed Cowbirds did not appear to shift among the three species and instead they exhibited a consistent preference for Dickcissel nests over the course of the breeding season and among years. Both the rate and the intensity of parasitism on Dickcissels were significantly lower during the present study than in one conducted several decades earlier at the same site. Our 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.</p>},
	keywords = {LTER-KNZ, Agelaius phoeniceus, Bell{\textquoteright}s Vireo, brood parasitism, community-level parasitism, Dickcissel, host use, Molothrus ater, multiple parasitism, red-winged blackbird, Spiza americana, Vireo bellii},
	doi = {10.1525/auk.2009.09053},
	url = {https://academic.oup.com/auk/article/127/2/263/5148382},
	author = {Rivers, J.W. and Jensen, W.E. and Kosciuch, K.L. and Rothstein, S.I.}
}
