Assessment of waterfowl body condition to evaluate the effectiveness of The Central Valley Joint Venture

The Central Valley Joint Venture (CVJV) was created in 1988 under the North American Waterfowl Management Plan to protect and enhance wetland and agriculture habitats beneficial to waterfowl in the Central Valley of California. One of the assumptions of the CVJV was that food resources were limiting for wintering waterfowl. This in turn limited waterfowl populations by negatively impacting body condition and ultimately survival, recruitment or both.;Body condition is the amount of endogenous reserves of a bird as fat. It can be measured in individual birds to evaluate food resource availability and, by extension, a metric of the quality and quantity of habitats available to waterfowl. My objective was to compare the body condition of northern pintail (Anas acuta), American wigeon (American wigeon), and northern shoveler (Anas clypeata), during 2006 to 2008 with the body condition of these three species collected prior to the creation of the CVJV.;I collected ducks during two wintering periods (September through February) from 2006-2008. I then used lipid extraction on these samples to determine the lipid mass, and then compared the body condition of pre-CVJV and post-CVJV birds.;I found that body condition of individual birds has improved between the two periods but the magnitude of those changes varied between species. Northern pintails showed the greatest positive response in body condition having higher levels of fat content throughout the winter during the post-CVJV period when compared to the preCVJV period. During the post-CVJV period, American wigeon and northern shoveler exhibited the greatest improvement during the months of November and December, but during the months of January and March body fat levels declined and were similar with the pre-CVJV period. My results indicate that habitat changes have increased food resources in the Central Valley, but that there is a differential effect between species with different feeding strategies and energetic demands.