The once-endangered Aleutian cackling geese began arriving last month at their wintering area near the Stanislaus and San Joaquin rivers west of Modesto. They will stay until mid-February, when they will begin trickling back up the coast to Oregon and Washington, where they will gather en masse before their lengthy flight back across the Pacific Ocean to their native Aleutian Islands.
By Monday, a cooperative effort between state and federal agencies, along with some volunteer students, trapped more than 100 of the birds to band them so that officials can track the geese's growing population. The trapping and banding will continue in the annual project until 200 birds or so have been tagged.
"This is their wintering area, so it's easier to band them here," said Eric Hopson, manager of the San Joaquin River National Wildlife Refuge. "They were listed as endangered throughout the 1970s, '80s and '90s. Now they've been taken off the endangered species act, and their population continues to grow. You can never count all of them; the best way to get a handle on that is to collar a sample of them."
The geese are caught by groups in nets, then transferred individually to cloth bags, where the bands are installed.
"I'm sure it's not a pleasant experience for them as individual birds, but it doesn't harm them at all," Hopson said.
He said the geese were near extinction, down to a population of about 1,000, because nonnative predators were introduced into the Aleutian Islands in the 1970s. Thanks to environmental efforts, he said, the geese are thriving again, up to about 135,000, according to a 2011 estimate.
Wintering in valley
While other geese and ducks migrate south to Mexico, these geese winter in the Stanislaus-San Joaquin counties area, feeding in farmers' fields on winter wheat and corn and nesting along the river. If you hear geese with a cackling honk and notice that they're flying west or northwest, they're probably the Aleutian variety, Hopson said, returning from a short trip farther south for food.
"They're always shifting around, depending on where they're finding a good feeding area," he said.
After they gather along the Pacific Northwest coast in March or April, they will leave the coastline and fly 1,200 miles across the ocean to their native terrain, Hopson said.
"They've got an internal compass," he said. "If they veered just a little west on their trip, they'd end up lost in the Pacific. It's amazing."
There is a viewing platform at the San Joaquin River National Wildlife Refuge where you can see the geese. Take Highway 132 west to Gates Road, then north on Gates and west on Beckwith Road for 1½ miles, where you'll see the viewing platform on the south side. It's open from sunrise to sunset from mid-October through mid-February. There are no restrooms available, just a parking area, Hopson warned.
And, he added, it's a viewing area only. Hiking is allowed on the Pelican Trail on another portion of the refuge west of the river. For more information, go to www.fws.gov/ sanluis/sanjoaquin_info.htm.
Modesto Bee staff writer Sue Nowicki can be reached at email@example.com or (209) 578-2012.