2026-09-22T19:22:35Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/89023 2023-07-11 col_2142_5131 col_2142_14737 com_2142_5130 com_2142_690 com_2142_397

Sperry, Jinelle H Kovar, Daniel George 2016-03-02T19:34:03Z 2016-03-02T19:34:03Z 2015-11-30 2015-12 Black-capped vireos (Vireo atricapilla) and white-eyed vireos (Vireo griseus) are closely related and ecologically similar. Despite these similarities, white-eyed vireos are widely distributed and common, whereas the black-capped vireo has a restricted breeding range and is federally endangered. Here I address this apparent paradox with a comparative ecological study of co-occurring black-capped and white-eyed vireos. I studied vireos in shrublands and woodlands in central Texas, USA in 2013 and 2014. I used point count surveys (n = 256) and nest monitoring (n = 145) to determine arrival dates, settlement patterns, nest site selection, and, ultimately, nest survival relative to temporal and habitat factors. Additionally, I conducted reciprocal playback trials (n = 16) to test for the presence of interspecific aggression. White-eyed vireos arrived first and established territories in shrub and woodland habitat with equal probability. Black-capped vireos arrive after white-eyed vireos and settled in greater numbers in shrubland habitat. White-eyed vireos begin initiating nests earlier than black-capped vireos and selected nest sites surrounded by taller, more mature, and more densely wooded vegetation. Playback trials failed to detect evidence of interspecific aggression, suggesting that competition with white-eyed vireos is not currently limiting black-capped vireos. For both species, nest survival declined as the season progressed, and was greater for nests in taller, more mature habitat. Accordingly, overall nest survival appeared greater for white-eyed vireos than black-capped vireos suggesting that the flexibility demonstrated by white-eyed vireos in where and when they nest confers a reproductive advantage. Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2016-03-02 without embargo terms The student, Daniel Kovar, accepted the attached license on 2015-11-30 at 10:27. The student, Daniel Kovar, submitted this Thesis for approval on 2015-11-30 at 13:50. This Thesis was approved for publication on 2015-11-30 at 14:47. DSpace SAF Submission Ingestion Package generated from Vireo submission #8867 on 2016-03-02 at 12:50:45 Made available in DSpace on 2016-03-02T19:34:03Z (GMT). No. of bitstreams: 3 KOVAR-THESIS-2015.pdf: 817098 bytes, checksum: 73b76fce16c14c89611f1175c56379d9 (MD5) DKovar_MS Thesis_v5.docx: 189731 bytes, checksum: bdd9b56d69a80bfcbccd7ceee2f3aad3 (MD5) LICENSE.txt: 4209 bytes, checksum: ce9b46176c60ee2719992dc83741c10e (MD5) Previous issue date: 2015-11-30 application/pdf http://hdl.handle.net/2142/89023 en Copyright 2015 Daniel George Kovar comparative ecology habitat selection interspecific competition endangered species management and conservation avian ecology nest site selection nest survival brood parasitism black-capped vireo Vireo atricapilla white-eyed vireo Vireo griseus Comparative reproductive biology of co-occurring endangered and common shrubland birds text text Natural Resources & Environmental Sciences Natural Resources & Environmental Sciences University of Illinois at Urbana-Champaign Thesis M.S.