Potential effects of drought on carrying capacity for wintering waterfowl in the Central Valley of California

Journal of Fish and Wildlife Management
By: , and 

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Abstract

We used the bioenergetics model TRUEMET to evaluate potential effects of California's recent drought on food supplies for waterfowl wintering in the Central Valley under a range of habitat and waterfowl population scenarios. In nondrought years in the current Central Valley landscape, food supplies are projected to be adequate for waterfowl from fall through early spring (except late March) even if waterfowl populations reach North American Waterfowl Management Plan goals. However, in all drought scenarios that we evaluated, food supplies were projected to be exhausted for ducks by mid- to late winter and by late winter or early spring for geese. For ducks, these results were strongly related to projected declines in winter-flooded rice fields that provide 45% of all the food energy available to ducks in the Central Valley in nondrought water years. Delayed flooding of some managed wetlands may help alleviate food shortages by providing wetland food resources better timed with waterfowl migration and abundance patterns in the Central Valley, as well as reducing the amount of water needed to manage these habitats. However, future research is needed to evaluate the impacts of delayed flooding on waterfowl hunting, and whether California's existing water delivery system would make delayed flooding feasible. Securing adequate water supplies for waterfowl and other wetland-dependent birds is among the greatest challenges facing resource managers in coming years, especially in the increasingly arid western United States.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Potential effects of drought on carrying capacity for wintering waterfowl in the Central Valley of California
Series title Journal of Fish and Wildlife Management
DOI 10.3996/082015-JFWM-082
Volume 7
Issue 2
Year Published 2016
Contributing office(s) Western Ecological Research Center
Description 15 p.
First page 408
Last page 422
Online Only (Y/N) N