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Consequences Of Dominance-Mediated Habitat Segregation In American Redstarts During The Nonbreeding Season, Peter P. Marra, Richard T. Holmes
Consequences Of Dominance-Mediated Habitat Segregation In American Redstarts During The Nonbreeding Season, Peter P. Marra, Richard T. Holmes
Dartmouth Scholarship
Several species of migratory songbirds exhibit a distinct form of habitat segregation while on their Neotropical wintering grounds in which males and females occupy different habitat types. In the American Redstart (Setophaga ruticilla), that sexual habitat segregation is a result of behavioral dominance of older males. In that study, we examined whether such dominance behavior and the resulting differential habitat segregation has consequences for the condition or survival of excluded individuals. We quantified the physical condition and survival of redstarts (both males and females) occupying two habitat types that differed in the proportion of males and females present …
Assessing Factors That May Predispose Minnesota Farms To Wolf Depredations On Cattle, L. David Mech, Elizabeth K. Harper, Thomas J. Meier, William J. Paul
Assessing Factors That May Predispose Minnesota Farms To Wolf Depredations On Cattle, L. David Mech, Elizabeth K. Harper, Thomas J. Meier, William J. Paul
USGS Northern Prairie Wildlife Research Center
Wolf (Canis lupus) depredations on livestock cause considerable conflict and expense in Minnesota. Furthermore, claims are made that such depredations are fostered by the type of animal husbandry practiced. Thus, we tried to detect factors that might predispose farms in Minnesota to wolf depredations. We compared results of interviews with 41 cattle farmers experiencing chronic cattle losses to wolves (chronic farms) with results from 41 nearby "matched" farms with no wolf losses to determine farm characteristics or husbandry practices that differed and that therefore might have affected wolf depredations. We also used a Geographic Information System (GIS) to …
Evaluation Of Fish Scale Chemistry For Determining Habitat Associations, Brian Kenneth Wells
Evaluation Of Fish Scale Chemistry For Determining Habitat Associations, Brian Kenneth Wells
Biological Sciences Theses & Dissertations
This is the first work examining the utility of scale chemistry for determining natal origins and habitat associations. I quantified a relationship of scale chemistry to water chemistry, quantified geographic variation in scale chemistry, and evaluated stability of scale chemistry through maturation. Scale chemistry accurately reflected trace element composition of the water in which fish had lived. Juvenile spot (Leiostomus xanthurus) were held in four concentrations of Sr, Cd, and Ba maintained at either 20°C or 25°C, for 42 days. Strontium:Ca, Cd:Ca, and Ba:Ca levels in scales were linearly related to environmental concentrations while temperature had no effect. …