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Do foraging methods in winter affect morphology during growth in juvenile snow geese?

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dc.contributor Háskóli Íslands
dc.contributor University of Iceland
dc.contributor.author Jónsson, Jón Einar
dc.contributor.author Afton, Alan D.
dc.date.accessioned 2017-09-27T14:48:58Z
dc.date.available 2017-09-27T14:48:58Z
dc.date.issued 2016-10-05
dc.identifier.citation Jónsson, J. E. and Afton, A. D. (2016), Do foraging methods in winter affect morphology during growth in juvenile snow geese?. Ecology and Evolution, 6: 7656–7670. doi: 10.1002/ece3.2481
dc.identifier.issn 2045-7758
dc.identifier.uri https://hdl.handle.net/20.500.11815/413
dc.description.abstract Physical exertion during growth can affect ultimate size and density of skeletal structures. Such changes from different exercise regimes may explain morphological differences between groups, such as those exhibited by lesser snow geese (Chen caerulescens caerulescens; hereafter snow geese) foraging in southwest Louisiana. In rice-prairie habitats (hereafter rice-prairies), snow geese bite off or graze aboveground vegetation, whereas they dig or grub for subterranean plant parts in adjacent coastal marshes. Grubbing involves considerably more muscular exertion than does grazing. Thus, we hypothesized that rates of bone formation and growth would be lower for juveniles wintering in rice-prairies than those in coastal marshes, resulting in smaller bill and skull features at adulthood. First, we tested this exertion hypothesis by measuring bills, skulls, and associated musculature from arrival to departure (November-February) in both habitats in southwest Louisiana, using both banded birds and collected specimens. Second, we used the morphological data to test an alternative hypothesis, which states that smaller bill dimensions in rice-prairies evolved because of hybridization with Ross's geese (C.rossii). Under the exertion hypothesis, we predicted that bill and skull bones of juveniles would grow at different rates between habitats. However, we found that bill and skull bones of juveniles grew similarly between habitats, thus failing to support the exertion hypothesis. Morphometrics were more likely to differ by sex or change with sampling date than to differ by habitat. We predicted that significant, consistent skewness toward smaller birds could indicate hybridization with Ross's geese, but no skewness was observed in our morphological data, which fails to support the hybridization hypothesis. Further research is needed to clarify whether snow geese wintering in Louisiana represent a single polymorphic population that segregates into individually preferred habitats, which we believe at present to be more likely as an explanation than two ecologically and spatially distinct morphotypes.
dc.description.sponsorship Canadian Wildlife Service, Louisiana Department of Wildlife and Fisheries (LDWF), Delta Waterfowl Foundation, Rockefeller Scholarship Program, USGS-Louisiana Cooperative Fish and Wildlife Research Unit, Graduate School; Agricultural Center, School of Renewable Natural Resources at Louisiana State University
dc.format.extent 7656-7670
dc.language.iso en
dc.publisher Wiley-Blackwell
dc.relation.ispartofseries Ecology and Evolution;6(21)
dc.rights info:eu-repo/semantics/openAccess
dc.subject Bill size
dc.subject Body size
dc.subject Foraging exertion
dc.subject Habitat selection
dc.subject Introgressive hybridization
dc.subject Morphotypes
dc.subject Snjógæs
dc.subject Fæðuöflun dýra
dc.subject Búsvæði
dc.subject Vöxtur (lífeðlisfræði)
dc.subject Beinin
dc.title Do foraging methods in winter affect morphology during growth in juvenile snow geese?
dc.type info:eu-repo/semantics/article
dcterms.license This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
dc.description.version Peer Reviewed
dc.identifier.journal Ecology and Evolution
dc.identifier.doi 10.1002/ece3.2481
dc.contributor.department Rannsóknasetur á Snæfellsnesi (HÍ)
dc.contributor.department Research Centre at Snæfellsnes (UI)

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