Fall Birds at Owens Lake

(Owens Lake is still a construction site.)

Folks from Audubon California once again joined volunteers from Eastern Sierra Audubon and the Los Angeles Department of Water and Power (LADWP) at the Owens Lake Important Bird Area this August to count birds. This is part of an annual one-day effort each spring and fall to count all the birds on the lake, both breeding and migrating. The data provides us with an important measure of how birds are responding to the habitat that has been created as a result of LA DWP’s rewatering of the lake. Temperatures can soar this time of year in the Eastern Sierra, and this year was no exception.

(Owens Lake in the dry season. Photo by Andrea Jones)

LADWP warned us that water level lakes were low this year so the count would not take too long. The low water level was a result of it being the dry season, a pipe broke, and LADWP needed some areas drier to obain aerial radar imagery of the lake’s surface to help guide future management efforts. This is also the time of year that lakes naturally recede in the desert, and the exposed mudflats provide important food and habitat for shorebirds along the pacifc flyway.

However, LA DWP has just turned back on the pipes and the lake is starting to fill – in preparation for the dust season this fall. It turns out this corresponds with bird migration as well. Mother nature was also helping out – as we counted birds, clouds gathered over the high sierras, bringing moisture from the Gulf which dropped onto Owens Valley that evening –bringing welcome relief I am sure to the valley.

The lesser amount of water meant that birds were concentrated wherever there were pools for the waterfowl and shallow flood habitat and exposed mud for the shorebirds. We still counted thousands of birds – many American Avocets, Least and Western Sandpipers, and large rafts of Northern Shovelers. In case one questioned what birds might be attracted to at Owens Lake this time of year – you need only look at the shoreline. It was covered with the casings of brine flies – the “lifeblood” of Owens Lake – shorebirds and gulls alike feed on these flies (that swarm in the millions) in order to fatten up and continue their migratory pathway to points south. Peering into the water, we also observed the brine shrimp – another source of food for many species of birds.

(Mike Prather, Eastern Sierra Audubon, examines brine fly casings. Photo by Andrea Jones)

Our group also visited Cottonwood Marsh, a natural marsh fed by groundwater along the western shore of the lake. Hidden from the highway, one could imagine standing at the old shore of the lake. The marsh is green this time of year. Blackbirds swarmed around us, and we looked for Burrowing Owls – frequently observed residing here. The string of green patches dotting the edge of the lake, known as seeps and springs, form an important part of the ecology of Owens Lake, providing home to wetland birds, and at one time, native fish. These wetlands and grasslands, in addition to the water and mudflats on the lake bed, are an important part of Audubon's planning efforts to advocate for the protection of the variety of habitats on Owens Lake into the future.

(Volunteers scan for Burrowing Owls and count shorebirds at Cottonwood Marsh. Photo by Andrea Jones.)

While continually amazed by the numbers of birds at the lake (we are still awaiting the final tally by LA DWP), I am also intrigued by the individual bird. Watching a Western Sandpiper I wonder if it was the same bird I saw in the spring? These birds nest in the high arctic and winter all the way into Panama and beyond. Where did this bird go, did it raise young this year, and has it now engraved in its brain that Owens Lake is a critical stop on the pacific flyway both spring and fall?

By Andrea Jones

September 05, 2012