TY - JOUR
T1 - Do habitat preferences improve fitness? Context-specific adaptive habitat selection by a grassland songbird
AU - Maresh Nelson, Scott B.
AU - Coon, Jaime J.
AU - Miller, James R.
N1 - We are grateful to J. Capozzelli, O. Garza, D. Jen, K. Malone, T. Park, T. Swartz, and B. Vizzachero for field assistance. We thank D. Debinski, W. Schacht, and D. Engle for contributing funding; J. Rusk and S. Rusk for managing pastures; T. J. Benson, J. Capozzelli, J. Fraterrigo, and R. Schooley for comments on the manuscript; P. Sterner and the Iowa Department of Natural Resources for access to lands; and many undergraduates for helping to process data. Partial funding was provided by the Competitive State Wildlife Grants program U-D F14AP00012 in cooperation with the U.S. Fish and Wildlife Service, Wildlife and Sport Fish Restoration Program; by the National Institute of Food and Agriculture, U.S. Department of Agriculture under award number ILLU-875-918; and by an award to SBMN and JJC from the Frances M. Peacock Scholarship for Native Bird Habitat from the Garden Club of America.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Animals are predicted to prefer high-quality over low-quality habitats, but adaptive habitat selection is less straightforward than often assumed. Preferences may improve only specific fitness metrics at particular spatial scales, with variation across time or between sexes. Preferences sometimes even reduce fitness. We investigated the context specificity of adaptive habitat selection, studying dickcissels (Spiza americana)—a polygynous songbird—as a model. From 2014 to 2015, we measured male and female habitat preferences at two scales (territories and landscape patches) on 21 grassland patches in Ringgold County, Iowa, USA. We tested whether preferences improved four fitness metrics—polygyny, avoidance of brood parasitism by brown-headed cowbirds (Molothrus ater), fledgling productivity, and offspring condition. Both sexes preferred territories where offspring attained superior condition and patches where parasitism was infrequent. Females preferred patches where nests produced more fledglings, and in 2014, males on preferred (i.e., early-established) territories attracted more mates and produced more fledglings. However, males on non-preferred (i.e., late-established) territories were more successful in 2015. This inconsistency may have arisen because females were abundant and nest-predation rates were low in May–June 2014, allowing early-settling males to produce many young. In 2015, however, females were more abundant and nests more successful later in the breeding season. Our results show that habitat preferences do not uniformly improve fitness, and some benefits differ between sexes. Moreover, preference–fitness relationships only manifest at specific scales, and annual variation in population and predation dynamics can limit consistency. Detecting adaptive habitat selection thus requires multi-year measurements and careful consideration of relevant scales.
AB - Animals are predicted to prefer high-quality over low-quality habitats, but adaptive habitat selection is less straightforward than often assumed. Preferences may improve only specific fitness metrics at particular spatial scales, with variation across time or between sexes. Preferences sometimes even reduce fitness. We investigated the context specificity of adaptive habitat selection, studying dickcissels (Spiza americana)—a polygynous songbird—as a model. From 2014 to 2015, we measured male and female habitat preferences at two scales (territories and landscape patches) on 21 grassland patches in Ringgold County, Iowa, USA. We tested whether preferences improved four fitness metrics—polygyny, avoidance of brood parasitism by brown-headed cowbirds (Molothrus ater), fledgling productivity, and offspring condition. Both sexes preferred territories where offspring attained superior condition and patches where parasitism was infrequent. Females preferred patches where nests produced more fledglings, and in 2014, males on preferred (i.e., early-established) territories attracted more mates and produced more fledglings. However, males on non-preferred (i.e., late-established) territories were more successful in 2015. This inconsistency may have arisen because females were abundant and nest-predation rates were low in May–June 2014, allowing early-settling males to produce many young. In 2015, however, females were more abundant and nests more successful later in the breeding season. Our results show that habitat preferences do not uniformly improve fitness, and some benefits differ between sexes. Moreover, preference–fitness relationships only manifest at specific scales, and annual variation in population and predation dynamics can limit consistency. Detecting adaptive habitat selection thus requires multi-year measurements and careful consideration of relevant scales.
KW - Brown-headed cowbird
KW - Dickcissel
KW - Polygyny
KW - Reproductive success
KW - Scale dependence
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U2 - 10.1007/s00442-020-04626-8
DO - 10.1007/s00442-020-04626-8
M3 - Article
C2 - 32201907
AN - SCOPUS:85082854179
SN - 0029-8549
VL - 193
SP - 15
EP - 26
JO - Oecologia
JF - Oecologia
IS - 1
ER -