Open Access. Powered by Scholars. Published by Universities.®

Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Eastern Illinois University

Molothrus ater

2006

Articles 1 - 3 of 3

Full-Text Articles in Biology

Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian D. Peer, Lyndon R. Hawkins, Edwin P. Steinke, Patricia Blair Bollinger, Eric K. Bollinger Jan 2006

Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian D. Peer, Lyndon R. Hawkins, Edwin P. Steinke, Patricia Blair Bollinger, Eric K. Bollinger

Eric K. Bollinger

The relationship between the Brownheaded Cowbird (Molothrus ater) and its cavitynesting hosts has received little attention because of the assumption that cowbirds rarely parasitize these hosts. We tested the Eastern Bluebird (Sialia sialis), a host that is sometimes heavily parasitized by cowbirds, for egg ejection behavior. Bluebirds ejected 65% of experimentally added cowbird eggs (n = 20), but ejected no experimentally added conspecific eggs (n = 66). This suggests that cowbird parasitism, not conspecific brood parasitism, is the selective pressure responsible for egg ejection in this species. This level of rejection may be conservative because bluebirds nest in dark cavities, …


Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian Peer, Lyndon Hawkins, Edwin Steinke, Patricia Bollinger, Eric Bollinger Jan 2006

Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian Peer, Lyndon Hawkins, Edwin Steinke, Patricia Bollinger, Eric Bollinger

Faculty Research & Creative Activity

The relationship between the Brownheaded Cowbird (Molothrus ater) and its cavitynesting hosts has received little attention because of the assumption that cowbirds rarely parasitize these hosts. We tested the Eastern Bluebird (Sialia sialis), a host that is sometimes heavily parasitized by cowbirds, for egg ejection behavior. Bluebirds ejected 65% of experimentally added cowbird eggs (n = 20), but ejected no experimentally added conspecific eggs (n = 66). This suggests that cowbird parasitism, not conspecific brood parasitism, is the selective pressure responsible for egg ejection in this species. This level of rejection may be conservative because bluebirds nest in dark cavities, …


Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian D. Peer, Lyndon R. Hawkins, Edwin P. Steinke, Patricia Blair Bollinger, Eric K. Bollinger Jan 2006

Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian D. Peer, Lyndon R. Hawkins, Edwin P. Steinke, Patricia Blair Bollinger, Eric K. Bollinger

Faculty Research & Creative Activity

The relationship between the Brownheaded Cowbird (Molothrus ater) and its cavitynesting hosts has received little attention because of the assumption that cowbirds rarely parasitize these hosts. We tested the Eastern Bluebird (Sialia sialis), a host that is sometimes heavily parasitized by cowbirds, for egg ejection behavior. Bluebirds ejected 65% of experimentally added cowbird eggs (n = 20), but ejected no experimentally added conspecific eggs (n = 66). This suggests that cowbird parasitism, not conspecific brood parasitism, is the selective pressure responsible for egg ejection in this species. This level of rejection may be conservative because bluebirds nest in dark cavities, …