Benedict, Lauryn

Committee Member

Franklin, Scott

Committee Member

McGlaughlin, Mitchell

Committee Member

Salo, Jessica


School of Biological Sciences: Biological Education


University of Northern Colorado

Type of Resources


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Greeley (Colo.)


University of Northern Colorado

Date Created



173 pages

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Born digital


Birds sing to advertise for mates and repel rivals, but there is enormous variety in how they do this. One of the best-studied and most intriguing questions in the field is how song varies in complexity from one bird to the next, at all taxonomic levels. Several studies have found associations between migratory behavior or latitudinal gradients and song complexity, but it remains unclear how universal this pattern is or what factors may be driving it. This small body of literature suffers from several problems, perhaps the most glaring of which is the lack of systematic, population-level studies. The main goals of this dissertation were to determine what evidence there is for the hypothesis that song complexity is influenced by latitude and/or migratory behavior and whether such a pattern can be detected in a single species, the rock wren (Salpinctes obsoletus). I recorded rock wren song at 11 sites in a latitudinal transect with both migratory and sedentary populations, and used morphological measurements and genome-level SNP scans to test my classification scheme of migratory versus sedentary populations. Song repertoire size was larger in sedentary rock wrens but did not vary with latitude, while migratory wrens had smaller mean repertoire sizes which increased with increasing latitude. Morphological measurements differed between migratory and sedentary populations, suggesting life history differences between these two groups. Population genetic structure was only apparent using outlier loci, but the resulting structure was not concordant with migratory behavior or site membership. Taken together, these results suggest migration does not pose a barrier to gene flow between migratory and sedentary populations, and that migratory and sedentary behavior is associated with differences in song complexity and morphology, although in a way inconsistent with any previously published hypotheses.


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