In seabirds, food availability is a driver of ecological and evolutionary processes. Here we examine how changes in food availability and energy demands affect both inter-specific resource partitioning and the genetic diversity within a species. We examined the effects of interannual fluctuations in food availability and predictable seasonal increases in energy demands on prey partitioning between breeding common (Uric aalge) and thick-billed (U. lomvia) murres. We observed strong spatial, temporal and dietary differences in the use of prey resources between the species. We found that partitioning increased as food availability declined and as energy demands increased during chick-rearing. We conclude that murres can buffer negative effects of warming and increased energy demands by reducing inter-specific competition for limited food resources. We also investigated the effects of contrasting foraging conditions and population trajectories on the genetic structure of common murres. We found that birds breeding on an increasing food-rich colony had higher genetic diversity than conspecifics breeding on a declining food-poor colony. This may be indicative of changes in a relative strength of purifying selection operating on increasing versus declining colonies. We conclude that foraging conditions might be driving the pattern of the genetic diversity in the Pacific common murre population.
Thesis (M.S.) University of Alaska Fairbanks, 2013
The export option will allow you to export the current search results of the entered query to a file. Different
formats are available for download. To export the items, click on the button corresponding with the preferred download format.
By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.
To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export.
The amount of items that can be exported at once is similarly restricted as the full export.
After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.