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Full-Text Articles in Natural Resources Management and Policy

Using Beaver Works To Estimate Colony Activity In Boreal Landscapes, Carol A. Johnston, Steve K. Windels Jul 2015

Using Beaver Works To Estimate Colony Activity In Boreal Landscapes, Carol A. Johnston, Steve K. Windels

Natural Resource Management Faculty Publications

Beaver ponds and beaver-impounded vegetation are indicators of past or present beaver activity that can be detected from aerial photography. A method to quantitatively relate these beaver works with the density of active beaver colonies could benefit beaver management, particularly in areas lacking beaver population data. We compared historical maps (1961–2006) of beaver works at Voyageurs National Park, Minnesota, USA with concurrent aerial surveys of beaver colonies. We tested 2 landscape-scale models of beaver colony density previously developed for a period of beaver population expansion (1940–1986), but they failed to predict colony density after 1986, a period of declining beaver …


Mate Replacement And Alloparental Care In Ferruginous Hawk, Shubham Datta, Will M. Inselman, Jonathan A. Jenks, Kent Jensen, Christopher C. Swanson, Robert W. Klaver, Indrani Sasmal, Troy W. Grovenburg Jun 2015

Mate Replacement And Alloparental Care In Ferruginous Hawk, Shubham Datta, Will M. Inselman, Jonathan A. Jenks, Kent Jensen, Christopher C. Swanson, Robert W. Klaver, Indrani Sasmal, Troy W. Grovenburg

Natural Resource Management Faculty Publications

Alloparental care (i.e., care for unrelated offspring) has been documented in various avian species (Maxson 1978, Smith et al. 1996, Tella et al. 1997, Lislevand et al. 2001, Literak and Mraz 2011). A male replacement mate that encounters existing broods has options, which include alloparental care or infanticide. Infanticide may be beneficial in some species (Rohwer 1986, Kermott et al. 1990), but in long-lived avian species, like the ferruginous hawk (Buteo regalis) that do not renest within a season, infanticide might be detrimental. Adoption and rearing success likely provide direct evidence of competence of replacement mates as potential parents for …