Robert G Clark

• Breeding Season Survival of Female Lesser Scaup in the Northern Boreal Forest

  Open Access•Rodney K Brook, Robert G Clark•ARTICLE•ARCTIC•2010

  Añadir item

  One hypothesis advanced to explain the decline in lesser scaup (Aythya affinis) populations during the past 20 years is that adult female survival has decreased. However, no survival probability estimates exist for the boreal forest, the region where most scaup breed. We captured and radio-marked female lesser scaup (n = 42) near Yellowknife, Northwest Territories, Canada, just before the breeding season in 1999 and 2000. Constant weekly survival…

• Stable-Nitrogen Isotope Enrichment in Avian Tissues Due to Fasting and Nutritional Stress

  K A Hobson, Ray T Alisauskas et al.•ARTICLE•Ornithological Applications•1993

  Añadir item

  Studies using measurements of δ 15N to delineate diet or trophic level in natural ecosystems are based on the premise that δ 15N values in consumer tissues can be reliably correlated with those in the diet. However, juvenile Japanese Quail (Coturnix japonica) fed a rationed diet designed to maintain, but not increase, body mass showed significantly enriched tissue δ 15N values over a control group fed the same diet ad libitum. We tested the hypot…

• Assessing Avian Diets Using Stable Isotopes II

  K A Hobson, Robert G Clark•ARTICLE•Ornithological Applications•1992

  Añadir item

  Studies using stable-isotope analysis to infer diet require a knowledge of how stable-isotope ratios in consumer tissues are related to dietary values. We determined δ 13C and δ 15N diet-tissue fractionation factors for blood, liver, muscle, bone collagen and feathers of domestic chickens (Gallus gallus), Japanese Quail (Coturnix japonica) and Ring-billed Gulls (Larus delawarensis) and for blood and feather samples of adult Peregrine Falcons (Fal…

• The American Public and American Institutions

  R Clark, Robert G Clark•ARTICLE•Public Opinion Quarterly•1975

  Añadir item

  THE AMERICAN PUBLIC AND AMERICAN INSTITUTIONS: SUPPORT AND CONFIDENCE IN A TIME OF SOCIAL TURBULENCE Get access Ruth Clark Ruth Clark Yankelovich. Skelly & White, Inc. Search for other works by this author on: Oxford Academic Google Scholar Public Opinion Quarterly, Volume 39, Issue 3, FALL 1975, Pages 413–415, https://doi.org/10.1093/poq/39.3.413-a Published: 01 January 1975

• The American Public and American Institutions

  R Clark, Robert G Clark•ARTICLE•Public Opinion Quarterly•1975

  Añadir item

  THE AMERICAN PUBLIC AND AMERICAN INSTITUTIONS: SUPPORT AND CONFIDENCE IN A TIME OF SOCIAL TURBULENCE Get access Ruth Clark Ruth Clark Yankelovich. Skelly & White, Inc. Search for other works by this author on: Oxford Academic Google Scholar Public Opinion Quarterly, Volume 39, Issue 3, FALL 1975, Pages 413–415, https://doi.org/10.1093/poq/39.3.413-a Published: 01 January 1975

• Assessing Avian Diets Using Stable Isotopes II

  K A Hobson, Robert G Clark•ARTICLE•Ornithological Applications•1992

  Añadir item

  Studies using stable-isotope analysis to infer diet require a knowledge of how stable-isotope ratios in consumer tissues are related to dietary values. We determined δ 13C and δ 15N diet-tissue fractionation factors for blood, liver, muscle, bone collagen and feathers of domestic chickens (Gallus gallus), Japanese Quail (Coturnix japonica) and Ring-billed Gulls (Larus delawarensis) and for blood and feather samples of adult Peregrine Falcons (Fal…

• Stable-Nitrogen Isotope Enrichment in Avian Tissues Due to Fasting and Nutritional Stress

  K A Hobson, Ray T Alisauskas et al.•ARTICLE•Ornithological Applications•1993

  Añadir item

  Studies using measurements of δ 15N to delineate diet or trophic level in natural ecosystems are based on the premise that δ 15N values in consumer tissues can be reliably correlated with those in the diet. However, juvenile Japanese Quail (Coturnix japonica) fed a rationed diet designed to maintain, but not increase, body mass showed significantly enriched tissue δ 15N values over a control group fed the same diet ad libitum. We tested the hypot…

• Breeding Season Survival of Female Lesser Scaup in the Northern Boreal Forest

  Open Access•Rodney K Brook, Robert G Clark•ARTICLE•ARCTIC•2010

  Añadir item

  One hypothesis advanced to explain the decline in lesser scaup (Aythya affinis) populations during the past 20 years is that adult female survival has decreased. However, no survival probability estimates exist for the boreal forest, the region where most scaup breed. We captured and radio-marked female lesser scaup (n = 42) near Yellowknife, Northwest Territories, Canada, just before the breeding season in 1999 and 2000. Constant weekly survival…

Biology (3 obras) · Ecology (3 obras) · Isotope Analysis in Ecology (2 obras) · Marine animal studies overview (2 obras) · Animal Ecology and Behavior Studies (1 obras) · Animal science (1 obras) · Avian ecology and behavior (1 obras) · Aythya (1 obras) · Boreal (1 obras) · Breed (1 obras)