Conservation Objectives for Wintering and Breeding Waterbirds in California's Central Valley

Abstract

Birds associated with wetlands have declined historically across North America from extensive\rhabitat loss and degradation. Among the regions most affected is California’s Central Valley, where\reScholarship provides open access, scholarly publishing\rservices to the University of California and delivers a dynamic\rresearch platform to scholars worldwide.\rover 90% of the wetland base has been lost. Still, this region remains of continental importance\rto waterbirds. On-the-ground conservation efforts for all bird groups are the focus of the Central\rValley Joint Venture, guided by a periodically updated implementation plan. To track progress\rtoward goal attainment, that plan sets time-bound, quantitative conservation goals. Lacking robust\rdata on the size and trends of populations of most species of waterbirds in the Central Valley,\rwe set conservation goals for this group by selecting 10 focal species. These species are of\rheightened conservation concern or are otherwise representative of the habitat needs of Central\rValley waterbirds. Given the great loss of historical habitat, we assumed focal species populations\rhave declined by ≥ 50%. Hence, we defined population objectives for most focal species as\rincreasing their current populations by 10% over 10 years and doubling them in 100 years. The\rcorresponding habitat objectives are to increase wetlands or enhance suitable crops for waterbirds\rin proportion to the population objectives. These include an increase over 10 years of 7,948\rha (19,641 acres) of winter seasonal wetlands, 921 ha (2,276 acres) each of semi-permanent\rand summer seasonal wetlands, and 573 ha (1,416 acres) of strategically placed riparian forest.\rAgricultural needs include additional winter flooding of 15,160 ha (37,461 acres) of rice and 2,137\rha (5,281 acres) of corn. We distributed the habitat objectives across five planning regions, in\rsome cases favoring proportionally larger increases in those regions with the greatest need.\rTo maximize success, however, conservationists must take into account the specific needs of\rindividual waterbird species, as a one-size-fits-all approach will not support the highest diversity\rof waterbirds.