Flight Above, Science Behind, and Teaching Beyond:
Developing a Sense of Place through Intergenerational and Multidisciplinary Science Learning on Bird Migration in the Understanding by Design Framework
CASE STUDY: CENTRAL CALIFORNIA FLYWAY
As a naturalist and teacher and supporter of place-based education, the Central Valley of California has become very valuable to me for many reasons, including its importance in bird study. The Central Valley is home to many diverse groups of people who are impacted by our understanding of bird migration in their area; hunters, farmers, loggers, businessmen, and naturalists to name a few. The Valley is utilized by 10-12 million of waterfowl and geese (accounting for 60% of the total population using the Pacific Flyway and 18% of the total continental populations) for resting, foraging, and wintering. Most birds are traveling from Alaska and Canada to milder wintering grounds. Conservation of this land is not a new subject. The US Fish & Wildlife Service has documented this data, environmental concerns, and challenges for at least 50 years in the Central Valley hoping to shift the focus on conserving breeding grounds to a wider scope of protection including wintering grounds (Bauer, Gilmer, LeDonne & Miller1982, p441).
In the northern reaches of the central valley, the Sacramento Refuge Complex includes six wildlife refuges and three wildlife management areas with a total area of 35,000 acres of wetlands and uplands of the Sacramento Valley. Colusa National Wildlife Refuge is one of five refuges in the Sacramento Refuge Complex and alone will support 200,000 ducks and 50,000 geese wintering each year in the seasonal marshes, permanent ponds, watergrass, and uplands (US Fish and Wildlife Service 2010). The Colusa National Wildlife Refuge (CNWR) characterizes the needs of migratory species visiting the area, as well as the human impacts on resources and conservation efforts to accommodate human development and protect this important migration corridor. CNWR was established in 1945 under the Authority of the Migratory Bird Treaty Act and the Lea Act. The Lea Act was a reaction to the loss of waterfowl habitat due to the growing rice production industry epitomized by the Sacramento Valley. The goals for the Refuge include feeding and resting habitat for the waterfowl, preserving biodiversity, alleviate crop depredation, and management for public enjoyment in observation and hunting. (Kramer)
Naturalist Stephen Walters is knowledgeable and avid hunter in the Central Valley with a vast knowledge of waterfowl habits in the area. Since December Walters has tracked numbers of Gadwall, Green-winged Teal, American Widgeon, Snow Geese and the growing population of Northern Pintail that have been utilizing local refuges. US Fish and Wildlife Service document that 40-80% percent of these species total migratory populations fly through the Central Valley (Bauer, et al. 1982, p.442). Specifically, Walters mentioned conservation efforts to protect the subspecies Tule Greater White-fronted Geese whose population is small but concentrated in the western Sacramento Valley (including the Colusa area). The Department of Fish and Game restrict hunting of the subspecies and hope to vigilantly measure harvests of White-fronted Geese. (Adolph 2007, image included)
As a hunter, Walters commented on the use of licensing fees to reach conservation goals. The cost of licensing has risen in recent years but Walters is unsure that funds entering lump sums for the state will be returned to support conservation efforts at the refuges. He is weary that funds meant for conservation efforts will be effective in a state with large anthropocentric problems at hand. (S. Walters, personal communication, January 23, 2010)
When discussing issues of migration and conservation with naturalist Zach Miller, he focused on a different aspect of the importance of the central valley flyway- raptors. The wetlands provide resources for millions of waterfowl each winter which in turn, provide prey for perhaps the most diverse population of raptors in any migratory corridor in North America. An expert birder and falconry apprentice, Miller commented on the numbers of shorebirds that attract falcons and the waterfowl that becomes meals for eagles. ‘When looking at range maps, the central valley is the only place you can find all three subspecies of Merlins’ as well as Rough-legged Hawks, Ferruginous Hawks, every Buteo except Broadwings and tropical species, American Kestrels among others. When asked about the conservation issues of the central valley, Miller noted the diversion of water and loss of wetlands as the major concern. Most of the water caught in the valleys extensive aqueduct system is transported to more arid regions in southern California. The conversion of wetlands to agriculture lands is the result of rice production area increasing twofold from 1950 to 1980. 95% of the wetland habitat loss has occurred in the last century leaving migratory waterfowl heavily dependent on refuge lands like those found in Colusa. (Bauer, et al. 1982, pgs.442,444)
What will happen to the central valley if conservation goals are not met in the future? Miller simply responded “Well, where else would these birds possibly go? If you looked at this land 500 years ago all you would find is a winter full of wetlands and waterfowl, nothing else.” The scale of change is even more severe than Miller proposes. In 1780, California’s land estimated 5 million acres of wetlands, 4 million of which were in the Central Valley. In 1978, 6% of the original wetlands remained and currently there is an estimated 500,000 acres (NPWRC 2006). When thinking about the changes that might occur, Miller describes the changes being seen in the Brandt migration on the coast as a parallel for unpredictable change in the valley. This year 30% fewer Brandts migrated south from northern breeding grounds. Initially, these birds flew south just ahead of the frozen isotherm of eelgrass habitat for a food resource. With less freezing occurring in eelgrass habitat in the north, Brandt’s do not need to migrate. Changes in the north will in turn affect migratory bird behaviors when further south. Snow geese populations are ‘artificially’ high this year in the central valley because they ‘have been eating themselves out of house and home on the tundra’ reports Miller. It is unclear what the cause for this behavior change but it was also reported by the Snow Goose Festival organizers. (Z. Miller, personal communication, January 24, 2010)