|A juvenile Black-necked Stilt in the shallow-water habitat that so many bird species require. Photo by Tom Grey / www.tgreybirds.com|
Since the Gold Rush, the state's land- and waterscapes have been altered in almost unimaginable ways. Today only one of the state's major rivers runs free (the Smith, in northern California), and Tulare Lake in the San Joaquin Valley--once the largest wetland complex west of the Mississippi--is but a faded memory.
Particularly stark is the contrast between today's summer waterscape and the expanses of wetlands and lakes that once teemed with breeding birds. This reality is only worsening, as state and federal private-lands conservation programs that support summer habitat are cut back, are eliminated, or shift their focus, and as rapid environmental change impacts the supply and availability of already scarce water resources.
Historic habitat losses have been partly offset, however, by the protection and restoration of more than 200,000 acres of wetlands in the Central Valley, two-thirds of which are privately owned. Our federal, state, non-profit, water district, and private landowner partners work tirelessly to provide flooded habitat to sustain migratory bird populations. It is largely because of them that the region still supports about 90% of the wintering waterfowl in the entire Pacific Flyway and remains the most important wintering area for shorebirds in the interior West.
|Figure 1 (Click here to open a larger map showing some of the areas mentioned in this Observer's water-related stories.).|
Key Central Valley wetlands have been provided with reliable and high-quality sources of water, thanks in large part to Congressional action associated with the passage of the Central Valley Project Improvement Act in 1992. Consequently, public and private investments of hundreds of millions of dollars have helped permanently protect these wetland resources.
Extensive flooding of agricultural lands during growing or post-harvest seasons also helps compensate for lost and degraded native wetlands. For example, approximately 350,000 acres of harvested rice fields are flooded in winter to aid in the decomposition of rice stubble while also providing waterbird habitat. PRBO is working with our conservation partners, the California rice industry, and individual growers to enhance the benefits of flooded croplands to wetland-dependent birds.
Nonetheless, California's water--its lifeblood--has been so over-allocated that today its wetlands and riparian forests are often anemic. Even federally mandated water supplies to critical habitats are not being met, due to increased demand and escalating costs (federal agencies must compete for water on the open market). Restoring healthy ecosystems across California, while sustaining economic integrity, is the ultimate balancing act--and our greatest challenge.
|The Black Tern once bred widely in California's wet landscape. Photo by Peter Latourrette|
PRBO is addressing this challenge. We have pioneered studies to assess the status of bird populations highly reliant on inland water (e.g., Mono Lake; see the profile of Dave Shuford in this issue). We have documented the importance of public incentive programs to private-land owners to sustain bird populations, partnered with agricultural interests to enhance habitat on working lands, and applied our scientific expertise to evaluate and guide restoration efforts along the state's major rivers, including the Sacramento and San Joaquin. We help envision a future for California that values our greatest treasures--bird and wildlife populations and the ecosystems that support them. This Observer tells of the challenges facing water-dependent birds in California, through the lens of three species with particular ecological requirements--the Long-billed Dowitcher, Black Tern, and Yellow Warbler.
History has shown that we cannot take for granted wetlands and riparian ecosystems. We must ensure the availability of water, especially as we face accelerating changes in our environment. If water is our lifeblood, wetland habitats are the life support system upon which bird populations, other wildlife, and we humans depend to survive and thrive.