A wet autumn should continue a trend this year of improving habitat for Swainson’s hawks, western sandpipers and other migratory birds that arrive in the Sacramento Valley via the Pacific Flyway, a major north-south migratory route, each winter.
This year’s wet spring relieved drought conditions and led to an increase of California’s waterfowl population, according to an August report by the U.S. Fish and Wildlife Service. The state’s population of ducks had dropped dramatically in 2015 because of the drought, but earlier this year the number of breeding ducks in California was up 30 percent over the year before, according to the wildlife service.
Migratory birds that fly south from Alaska each winter gather in wildlife areas throughout California, including the Cosumnes River Preserve south of Elk Grove. The 50,000-acre preserve, filled with wetlands and meadows, is co-owned by state and local governments and nonprofits including the Nature Conservancy and Ducks Unlimited.
December is the best time to visit the preserve. It’s when the winter migratory population reaches its peak – almost 80,000 birds in recent years, said Harry McQuillen, preserve manager.
Even during the past four drought years, the migratory-bird population remained relatively stable. The preserve saw a one-time decline in bird population of about 35 percent between 2012 and 2013, but it is not clear what caused it, McQuillen said.
The Cosumnes preserve is less susceptible to drought risks because of its management program involving irrigation, soil preparation and other methods to make sure there is plenty for the birds to eat, he said. Some birds fly as far as 3,000 miles to get to the preserve.
“That’s pretty energetically expensive. They burn up a lot of their fat stores,” McQuillen said. “Our job as wetland managers is to try to replenish those supplies for them. Everything you see here looks this way because we make it look this way.”
About 250 bird species can be found at the preserve at various times of the year, and most of them are migratory. White-fronted geese are the most common in November.
McQuillen recommends that winter visitors to the preserve go down Desmond Road to see birds clustered in wetland ponds next to the road. Last week, McQuillen drove on that road, to a section of the preserve where rice had been planted. Geese and other birds had flocked to that location and soon filled the sky.
“That’s why I do this job,” he said, smiling.
Cosumnes River Preserve
What: The next few weeks are the best time to see winter migratory birds at the Cosumnes River Preserve. Birds fly from as far as Alaska to spend winters there.
Where: The preserve’s visitor center is at 13501 Franklin Blvd. in Galt.
How: There is no charge to visit the preserve. The preserve has trails and recommended driving tours. Information is available at the visitor’s center.