Small remnants of 'natural' habitats exist today throughout much of the world. Upland prairies in the Willamette Valley, Oregon have been nearly eliminated by conversion to agriculture and other uses. As a result, very few prairies remain and at least four butterfly species that require this habitat appear to be...
Morphologically divergent ecotypes arise in fish populations on postglacial time scales, and resource polymorphisms
are often invoked to explain their origin. However, genetic recombination can constrain the ability of divergent selection to produce
reproductive isolation in sympatry. Recombination breaks up favorable combinations of traits (”adaptive suites”) if individual
traits are...
The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat is fisheries-related mortality. The Maui's dolphin is among the most critically endangered cetaceans in the world, with its remnant population primarily...
One of the biggest challenges when conducting a national-scale assessment of lakes, such as the 2007 US National Lake Assessment (NLA), is finding enough reference lakes to set appropriate expectations for the assessed sites. In the NLA, a random design was used to select lakes for sampling to make unbiased...
Landscape characteristics can strongly influence demographic and genetic processes in wildlife populations. Climate change and human land use are causing many landscapes to change rapidly, and the effects on wildlife populations must be understood to properly manage these threats and design effective conservation strategies. In this dissertation, I explored the...
Marine protected areas (MPAs) are increasingly being used as a conservation tool for highly mobile marine vertebrates and the focus is typically on protecting breeding areas where individuals are aggregated seasonally. Yet movements during the non-breeding season can overlap with threats that may be equally as important to population dynamics....
Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems—marshes, mangroves, and seagrasses—that may be lost with habitat destruction (‘conversion’). Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this ‘blue...
Land use and climate change occur simultaneously around the globe. Fully understanding their separate and combined effects requires a mechanistic understanding at the local scale where their effects are ultimately realized. Here we applied an individual-based model of fish population dynamics to evaluate the role of local stream variability in...
The genetic basis of adaptation is complex as many fitness-related traits are quantitative and likely influenced by multiple genes with variable effects across different selective environments. One important adaptation for anadromous Chinook salmon (Oncorhynchus tshawytscha) is the time at which individuals return to natal breeding sites within a reproductive season....