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Full-Text Articles in Life Sciences

Breeding Origins Of Northern Shovelers (Anas Clypeata) Wintering On The Great Salt Lake, Utah, Anthony J. Roberts, Michael R. Conover Sep 2014

Breeding Origins Of Northern Shovelers (Anas Clypeata) Wintering On The Great Salt Lake, Utah, Anthony J. Roberts, Michael R. Conover

Wildland Resources Faculty Publications

The breeding origin and migratory connectivity of wintering birds are important to address how population changes on wintering areas are impacted by changes elsewhere in the birds’ annual cycle. In addition, identifying important point sources of nutrients used throughout the annual cycle can assist managers in identifying sources of toxins or pathogens. We used stable hydrogen isotope ratios to identify breeding locations of Northern Shovelers (Anas clypeata; henceforth shoveler) wintering at the Great Salt Lake (GSL), Utah. Stable-isotope likelihood-based assignment placed the largest number of shovelers collected during winter on the GSL as breeding in the western US and southern ...


Diet And Body Mass Of Ducks In The Presence Of Commercial Harvest Of Brine Shrimp Cysts In The Great Salt Lake, Utah, Anthony J. Roberts, Michael R. Conover Aug 2014

Diet And Body Mass Of Ducks In The Presence Of Commercial Harvest Of Brine Shrimp Cysts In The Great Salt Lake, Utah, Anthony J. Roberts, Michael R. Conover

Wildland Resources Faculty Publications

Commercial fisheries and waterbirds are often in competition for available resources and may affect each other through limiting available forage for birds or reducing harvest for commercial fisheries. Relatively little is known regarding the wintering population of waterfowl on the hypersaline Great Salt Lake (GSL), Utah, but mid-winter counts indicate waterfowl use the GSL during winter coinciding with a commercial harvest of brine shrimp (Artemia franciscana) cysts (i.e., eggs). We surveyed previously unmonitored pelagic regions of GSL to estimate total wintering populations of waterfowl and collected northern shoveler (Anas clypeata) and green-winged teal (Anas crecca) during 3 nonbreeding seasons ...


Role Of Benthic Substrate In Waterfowl Distribution On Great Salt Lake, Anthony J. Roberts, Michael R. Conover Jun 2014

Role Of Benthic Substrate In Waterfowl Distribution On Great Salt Lake, Anthony J. Roberts, Michael R. Conover

Wildland Resources Faculty Publications

Benthic substrate has a large impact on aquatic plant and invertebrate assemblages and likely directly or indirectly influences waterbird distributions. The association of birds with various substrates can be important in survey design or habitat management. Northern Shoveler (Anas clypeata), Common Goldeneye (Bucephala clangula), Eared Grebe (Podiceps nigricollis), Ring-billed Gull (Larus delawarensis) and California Gull (L. californicus) densities on the hypersaline Great Salt Lake, Utah, were estimated to determine the association of bird distributions with benthic substrates. Three of the four groups of species monitored had densities that varied by benthic substrate; gulls were the exception. Eared Grebes occurred at ...


Greater Sage-Grouse (Centrocercus Urophasianus) Hen Survival: Effects Of Raptors, Anthropogenic And Landscape Features, And Hen Behavior, Jonathan B. Dinkins, Michael R. Conover, Christopher P. Kirol, Jeffrey L. Beck, S. Nicole Frey Feb 2014

Greater Sage-Grouse (Centrocercus Urophasianus) Hen Survival: Effects Of Raptors, Anthropogenic And Landscape Features, And Hen Behavior, Jonathan B. Dinkins, Michael R. Conover, Christopher P. Kirol, Jeffrey L. Beck, S. Nicole Frey

Wildland Resources Faculty Publications

Survival of breeding-age hens has been identified as the demographic rate with the greatest potential to influence population growth of Greater Sage-Grouse (Centrocercus urophasianus (Bonaparte, 1827); hereafter “Sage-Grouse”). During 2008–2011, we collected summer survival data from 427 Sage-Grouse hens in southern Wyoming, USA. We assessed the effects of raptor densities, anthropogenic features, landscape features, and Sage-Grouse hen behavior on Sage-Grouse hen survival. Survival of Sage-Grouse hens was positively associated with the proportion of big sagebrush (genus Artemisia L.) habitat within 0.27 km radius and road density and negatively associated with power-line density, proximity to forested habitat, and topographic ...