02482nas a2200253   4500008004100000245009700041210006900138300001400207490000700221520169100228653002401919653001201943653001901955653002101974653002501995653001902020653002602039653002502065653001702090100001902107700001902126700002202145856006102167       2014                        eng d00aMismatched begging displays between foreign and host offspring reduce brood parasite fitness0 aMismatched begging displays between foreign and host offspring r  a785 - 7930 v253 a<p>Obligate brood parasites must obtain food from unrelated host parents during the developmental period, and this may be especially difficult when parasitic nestlings are raised alone. Unlike specialist brood parasites, generalist brood parasites use a single begging display for a range of host species. In this study, we 1) tested whether the begging display of the generalist brown-headed cowbird (Molothrus ater) was more exaggerated than the closely related, nonparasitic red-winged blackbird (Agelaius phoeniceus) and 2) examined how begging displays were linked to food provisioning when both foreign species were raised by the Bell&rsquo;s vireo (Vireo bellii), a small cowbird host. We also quantified parental provisioning to unparasitized broods containing 1&ndash;4 vireo nestlings to provide a reference provisioning curve to provide context for assessing the feeding rate to foreign offspring. We found blackbirds begged as intensely as (or more intensely than) cowbird nestlings, vireo parents provisioned both species similarly, and the amount of food provisioned to unparasitized broods increased with brood size and maintained per-capita vireo growth. However, feeding of a single foreign nestling was significantly less than that of a modal brood of 4 vireos, indicating parents fed foreign nestlings at submaximal rates. Vireos did not respond to begging of foreign nestlings in the same manner as their own offspring, and this led to significant fitness costs for foreign nestlings. We conclude that a single foreign nestling provided an inadequate stimulus for vireos, probably because of a mismatch between the begging displays of foreign and host offspring.</p>10aAgelaius phoeniceus10abegging10aBell’s vireo10abrood parasitism10abrown-headed cowbird10aMolothrus ater10aprovisioning behavior10ared-winged blackbird10aVireo bellii1 aRivers, J., W.1 aBlundell, M.A.1 aRothstein, S., I.  uhttps://academic.oup.com/beheco/article/25/4/785/2900528