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Filters: Tags: Monitoring 1-Changes in Plant and Animal Distribution: Fauna (X)

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We examined age- and sex-related differences in the timing of Wilson's Warbler (Wilsonia pusilla pileolata) migration at four locations in Alaska: Fairbanks, Tok, Mother Goose Lake, and Yakutat. We captured Wilson's Warblers with mist nets for ≥5 years during spring (northbound) and autumn (southbound) migration. In spring, males passed through our two northernmost sites-Tok and Fairbanks-earlier than females. During autumn, timing of adult migration did not differ by sex, but immatures passed through earlier than adults at all four sites. During previous studies of autumn passage sampled at lower latitudes, the lack of age-related differences in migration timing could be attributed to adults migrating faster than...
Winters in interior Alaska (64°N) are characterized by short photoperiod (5L:19D) and chronic subfreezing temperatures. To determine if seasonal acclimatization of black‐capped chickadees (Poecile atricapilla) at high latitude differs from that of conspecifics at lower latitudes, standard metabolic rates (SMR), metabolic response to low temperature (−30°C), nocturnal hypothermia, body mass, fat reserves, and conductance were measured over two winters and one summer in three groups of seasonally acclimatized birds. Body mass and conductance did not vary with season, although furcular fat levels were higher in winter. Birds used nocturnal hypothermia when exposed to −30°C in summer or winter. Although SMR did not...
A statewide database and GIS has been created for amphibian observations in the National Parks of Alaska. This database contains the records for an opportunistic survey of 2001-2003.
A statewide database and GIS has been created for amphibian observations in the National Parks of Alaska. This database contains the records for an opportunistic survey of 2001-2003.
How do organisms diversify or "radiate" in nature? I studied an Alaskan threespine stickleback adaptive radiation to examine the rate at which organisms adapt to novel environmental conditions and the importance of different factors that facilitate or constrain adaptive radiation in nature. My dissertation research consisted of two main components. First, I exploited a recently established population in Loberg Lake to examine the rate and pattern of stickleback adaptation in nature. I established baseline phenotypic variation and covariation using its most likely ancestor, a sea-run population from the same drainage. Within 25 years of establishment, the Loberg Lake population evolved from the ancestral phenotype...
A spruce beetle (Dendroctonus rufipennis) epidemic in southcentral Alaska has caused extensive mortality to spruce trees and a change in forest stand structure. Because a change in forest vegetation can influence composition and abundance of forest birds, we attempted to assess the type and magnitude of change in bird populations within 2 forest stands on the Kenai Peninsula that were undergoing differing levels of spruce beetle infestation. In addition, we compared bird populations occupying a salvage-logged forest site with those in the other forest stands. During our survey period (1994 to 1998), species composition and abundance of land birds differed across the sampled forest stands. Avian species diversity...