| 1. |
- Caplat, Paul, et al.
(författare)
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Looking beyond the mountain: dispersal barriers in a changing world
- 2016
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Ingår i: Frontiers in Ecology and the Environment. - : Wiley. - 1540-9295 .- 1540-9309. ; 14:5, s. 262-269
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Tidskriftsartikel (refereegranskat)abstract
- Dispersal barriers have demographic, evolutionary, and ecosystem-wide consequences. With ongoing changes in the environment, some dispersal barriers will likely disappear while new ones will appear, and it is crucial to understand these dynamics to forecast species' distributions and adaptive potential. Here we review recent literature on the ecological and evolutionary aspects of dispersal to highlight key dynamics of dispersal barriers in the face of global change. After defining dispersal barriers, we explain that a better understanding of their dynamics requires identifying the barrier types that are most susceptible to change and predicting species' responses. This knowledge is a prerequisite for designing management strategies to increase or reduce connectivity, and maintain adaptive potential. Our intent is to motivate researchers to explicitly consider dispersal barriers in order to better forecast the dynamics of species and ecosystems subject to global change.
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| 2. |
- Ninnes, Calum E., et al.
(författare)
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A receiver bias for red predates the convergent evolution of red color in widowbirds and bishops
- 2015
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 26:4, s. 1212-1218
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Tidskriftsartikel (refereegranskat)abstract
- In the African widowbirds, icons of sexual selection, bright red plumage colors are agonistic (threat) signals in territorial competition, but in the congeneric bishop birds, color functions remain obscure. In the yellow-crowned bishop, the earliest branching lineage of the genus, an experimentally introduced red color patch gave a competitive advantage over yellow. This indicates agonistic sexual selection for red also in bishops, and that a receiver bias predated the evolution of red coloration in the genus.Preexisting receiver biases are well known and empirically supported alternatives or complements to signal evolution through coevolving mate choice, but largely neglected as drivers of sexually or socially selected agonistic signal evolution. In further pursuit of a recently revealed receiver bias for red agonistic signaling in Euplectes (17 species of widowbirds and bishops), we investigate here its presence in the yellow-crowned bishop (Euplectes afer), a representative of the earliest phylogenetic branch of the genus. In a captive population in southern Spain, where the yellow-crowned bishop is invasive, we staged and filmed 10-min dyadic contests over access to a feeder, between males with experimentally yellow- (control-) and red-painted crown plumage, respectively. Red males secured significantly more time at the feeder, and tended to win more of the limited number of supplant attempts observed. This suggests that the previously demonstrated agonistic signal function of red carotenoid coloration in widowbirds also applies to the bishop birds, and may derive from a receiver bias (aversion) that is substantially older than the convergent gains of red plumage pigmentation in Euplectes, and perhaps also predating the evolution of red in a few other weaverbird (Ploceidae) lineages. Given the similarities in ecology and behavior across Euplectes, the color diversity appears to primarily be a consequence of evolutionary limitations on mechanisms for achieving red coloration.
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