Agricultural practices and residual corn during spring crane and waterfowl migration in Nebraska

Journal of Wildlife Management
By: , and 

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Abstract

Nebraska's Central Platte River Valley (CPRV) is a major spring-staging area for migratory birds. Over 6 million ducks, geese, and sandhill cranes (Grus canadensis) stage there en route to tundra, boreal forest, and prairie breeding habitats, storing nutrients for migration and reproduction by consuming primarily corn remaining in fields after harvest (hereafter residual corn). In springs 2005-2007, we measured residual corn density in randomly selected harvested cornfields during early (n=188) and late migration (n=143) periods. We estimated the mean density of residual corn for the CPRV and examined the influence of agricultural practices (post-harvest field management) and migration period on residual corn density. During the early migration period, residual corn density was greater in idle harvested fields than any other treatments of fields (42%, 48%, 53%, and 92% more than grazed, grazed and mulched, mulched, and tilled fields, respectively). Depletion of residual corn from early to late migration did not differ among post-harvest treatments but was greatest during the year when overall corn density was lowest (2006). Geometric mean early-migration residual corn density for the CPRV in 2005-2007 (42.4 kg/ha; 95% CI=35.2-51.5 kg/ha) was markedly lower than previously published estimates, indicating that there has been a decrease in abundance of residual corn available to waterfowl during spring staging. Increases in harvest efficiency have been implicated as a cause for decreasing corn densities since the 1970s. However, our data show that post-harvest management of cornfields also can substantially influence the density of residual corn remaining in fields during spring migration. Thus, managers may be able to influence abundance of high-energy foods for spring-staging migratory birds in the CPRV through programs that influence post-harvest management of cornfields. ?? 2011 The Wildlife Society.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Agricultural practices and residual corn during spring crane and waterfowl migration in Nebraska
Series title Journal of Wildlife Management
DOI 10.1002/jwmg.157
Volume 75
Issue 5
Year Published 2011
Language English
Contributing office(s) Northern Prairie Wildlife Research Center
Description 9 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Wildlife Management
First page 995
Last page 1003