TY - JOUR
T1 - Food Selection by Spring-Migrating Green-Winged Teal
AU - Klimas, Samuel T.
AU - Osborn, Joshua M.
AU - Yetter, Aaron P
AU - Lancaster, Joseph D.
AU - Jacques, Christopher N.
AU - Fournier, Auriel M.V.
AU - Hagy, Heath
N1 - We thank C. Beach, J. Colbaugh, D. McClain, S. McClain, A. Gilbert, M. Greider-Wagner, M. Jugovic, J. Lux, L. Malanchuk, J. Novobilsky, F. O’Hara, S. Owens, J. Schmidt, M. Shaw, A. Shaw, B. Sullivan, D. Wu, J. Yetter, and K. Yetter for assistance during field and laboratory work and the Illinois Department of Natural Resources (IDNR), The Nature Conservancy, U.S. Fish and Wildlife Service (USFWS), and private landowners for granting access to wetlands. Support and funding for this research was provided by the IDNR through the Federal Aid in Wildlife Restoration Program, the Illinois Natural History Survey – Prairie Research Institute at the University of Illinois, Western Illinois University, and the Forbes Biological Station – Frank C. Bellrose Waterfowl Research Center. We also thank the Associate Editor and two anonymous
We thank C. Beach, J. Colbaugh, D. McClain, S. McClain, A. Gilbert, M. Greider-Wagner, M. Jugovic, J. Lux, L. Malanchuk, J. Novobilsky, F. O’Hara, S. Owens, J. Schmidt, M. Shaw, A. Shaw, B. Sullivan, D. Wu, J. Yetter, and K. Yetter for assistance during field and laboratory work and the Illinois Department of Natural Resources (IDNR), The Nature Conservancy, U.S. Fish and Wildlife Service (USFWS), and private landowners for granting access to wetlands. Support and funding for this research was provided by the IDNR through the Federal Aid in Wildlife Restoration Program, the Illinois Natural History Survey – Prairie Research Institute at the University of Illinois, Western Illinois University, and the Forbes Biological Station – Frank C. Bellrose Waterfowl Research Center. We also thank the Associate Editor and two anonymous reviewers for providing valuable commentary that improved the quality of the manuscript. Any use of trade, product, website, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.
PY - 2022/6
Y1 - 2022/6
N2 - The Mississippi Flyway supports millions of waterfowl during spring migration as individuals replenish vital nutrients en route to breeding locations. Green-winged teal Anas crecca consume natural plant and animal foods in shallow wetlands during autumn and winter, but little information is available to describe food use and selection during spring migration. We experimentally collected green-winged teal and quantified food use and availability to determine selection in the Illinois River Valley during February–April 2016–2018. We removed, dried, and weighed (60.1 mg) food items by taxa from the upper digestive tract (proventriculus and esophagus) of birds and core samples for comparison. Additionally, we evaluated retention of common diet items between small (#60; 250 lm) and medium (#35; 500 lm) sieves and the effect of processing sieve size on selection coefficients. Seeds of moist-soil vegetation occurred in all green-winged teal diets, while invertebrates and vegetation material occurred in 67.4% and 25.8% of diets, respectively. Green-winged teal consumed 85.8% (CI95 ¼ 81.2–90.3%) plant material and 14.2% (CI95 ¼ 9.6–18.7%) invertebrates based on aggregate dry biomass. We failed to find support for selection of either plant or animal foods in general, but green-winged teal selected Cyperus spp., Ammannia spp., Leptochloa spp., and Potamogeton spp. and avoided Amaranthus spp., Ipomoea spp., Echinochloa spp., and Oligochaeta individual taxa. We found no support for a difference in selection ratios between sexes, but selection ratios differed among years and wetland connectivity regimes with changes in food availability. Sieve size had minimal impact on rank and selection intensity of most food items, but only small sieves captured Ammannia spp., which was an important diet item. We found no evidence that green-winged teal selected invertebrates in our midlatitude migration study area, as has been speculated for dabbling ducks in general during spring migration (i.e., spring diet-shift hypothesis). We encourage managers to provide shallowly flooded wetlands with desirable plant taxa (e.g., Cyperus spp., Ammannia spp., Leptochloa spp.) for green-winged teal by maintaining actively managed moist-soil wetlands that are made available during spring migration.
AB - The Mississippi Flyway supports millions of waterfowl during spring migration as individuals replenish vital nutrients en route to breeding locations. Green-winged teal Anas crecca consume natural plant and animal foods in shallow wetlands during autumn and winter, but little information is available to describe food use and selection during spring migration. We experimentally collected green-winged teal and quantified food use and availability to determine selection in the Illinois River Valley during February–April 2016–2018. We removed, dried, and weighed (60.1 mg) food items by taxa from the upper digestive tract (proventriculus and esophagus) of birds and core samples for comparison. Additionally, we evaluated retention of common diet items between small (#60; 250 lm) and medium (#35; 500 lm) sieves and the effect of processing sieve size on selection coefficients. Seeds of moist-soil vegetation occurred in all green-winged teal diets, while invertebrates and vegetation material occurred in 67.4% and 25.8% of diets, respectively. Green-winged teal consumed 85.8% (CI95 ¼ 81.2–90.3%) plant material and 14.2% (CI95 ¼ 9.6–18.7%) invertebrates based on aggregate dry biomass. We failed to find support for selection of either plant or animal foods in general, but green-winged teal selected Cyperus spp., Ammannia spp., Leptochloa spp., and Potamogeton spp. and avoided Amaranthus spp., Ipomoea spp., Echinochloa spp., and Oligochaeta individual taxa. We found no support for a difference in selection ratios between sexes, but selection ratios differed among years and wetland connectivity regimes with changes in food availability. Sieve size had minimal impact on rank and selection intensity of most food items, but only small sieves captured Ammannia spp., which was an important diet item. We found no evidence that green-winged teal selected invertebrates in our midlatitude migration study area, as has been speculated for dabbling ducks in general during spring migration (i.e., spring diet-shift hypothesis). We encourage managers to provide shallowly flooded wetlands with desirable plant taxa (e.g., Cyperus spp., Ammannia spp., Leptochloa spp.) for green-winged teal by maintaining actively managed moist-soil wetlands that are made available during spring migration.
KW - food
KW - management
KW - selection
KW - waterfowl
KW - wetland
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U2 - 10.3996/JFWM-21-075
DO - 10.3996/JFWM-21-075
M3 - Article
AN - SCOPUS:85132398749
SN - 1944-687X
VL - 13
SP - 155
EP - 168
JO - Journal of Fish and Wildlife Management
JF - Journal of Fish and Wildlife Management
IS - 1
ER -