Ecology of spring-migrating waterfowl within the lower Wabash River floodplain

abundance;aerial survey;behavior;dabbling ducks;detection;foraging;habitat;Illinois;Indiana;mallards;landscape;presence;repeatability;spring migration

Hennig, Jacob ; Benson ; Thomas J.

关键词: abundance;    aerial survey;    behavior;    dabbling ducks;    detection;    foraging;    habitat;    Illinois;    Indiana;    mallards;    landscape;    presence;    repeatability;    spring migration;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/50444/Jacob_Hennig.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Spring migration is an understudied, but important time for waterfowl as conditions faced during this period may affect reproductive success.Therefore, increasing our understanding of waterfowl ecology during spring is vital for maintaining desired population levels.The Midwestern United States has lost much of its historical wetland habitat since European settlement, yet this area still contains habitat critical for many waterfowl species.The lower Wabash River floodplain, in southeastern Illinois and southwestern Indiana, has been anecdotally suggested to contain suitable habitat for large concentrations of migratory waterfowl, but currently lacks robust estimates of waterfowl use.Therefore, I designed and evaluated a grid-based sampling approach involving replicate counts to examine spatial and temporal trends of waterfowl use within the region.Furthermore, I explored how local habitats and landscape metrics influenced waterfowl behavior during this important time period.I estimated peak abundances of >300,000 and >700,000 ducks during early February in 2012 and 2013, respectively.The grid-based sampling approach proved effective for estimating waterfowl abundance in this region given its relatively precise estimates (mean CV < 0.30 for dabbling ducks), high repeatability of counts, and high detection probability (0.68).The presence of flood water and the amount of open water per site were the best predictors of dabbling duck presence while flood water and herbaceous wetlands were the strongest predictors of duck abundance.Dabbling ducks spent the majority of their time foraging (55%) with foraging rate greatest in emergent, open water, and agricultural habitats.The natural flooding regime of the Wabash River allows this area to provide ample high-quality habitat for large concentrations of waterfowl during spring.Given the juxtaposition of this region in relation to prime wintering and breeding grounds, the lower Wabash River floodplain appears to be important for migrating waterfowl.Conservation strategies should be developed to ensure that this region continues to provide high-quality stopover habitat.Actions should focus on enhancing existing wetlands as well as acquiring or restoring new wetlands to improve the overall quality of stopover habitat for spring-migrating ducks.