Saturday, October 11, 2014

Passion Amongst the Willows: Saving Yellow-billed Cuckoos

I have never seen a yellow-billed cuckoo, except in a clock, but chances are I never will. They're good at staying hidden, but experts say their numbers in California are dropping fast. That prompts government action so you, like me, might one day have a chance to see and especially hear this fascinating species.

Courtesy: Audubon Society
To hear these birds, to know their song, is to witness passion through sound. The experts at the Cornell Lab of Ornithology also say yellow-billed cuckoos are fairly easy to hear, but hard to spot.

In summer, they suggest looking in areas of deciduous forest for infestations of tent caterpillars, as well as outbreaks of cicadas or other large arthropods. Then listen for the species’ distinctive, knocking call, which can be given at any time, night or day. Later in summer, listen more for their dove-like cooing, as they give their knocking call much less frequently.

When the birds have feasted on caterpillars and insects and feel secure, experts say a receptive female may perch with its head up, pumping its tail slowly up and down in a 180-degree arc. Just prior to mating, the male yellow-billed cuckoo snaps off a short twig and presents it to the female as he perches on her back and leans over her shoulder.

Both birds then grasp the twig as they copulate. When they leave their sheltered perch, the yellow-billed cuckoo’s flight is swift and direct, with deep beats of their long pointed wings.

In California the birds live in willows along streams. Once common in the California’s Central Valley, coastal valleys, and riparian habitats east of the Sierra Nevada, habitat loss now constrains the California breeding population to small numbers of birds along the Kern, Sacramento, Feather and Lower Colorado Rivers.

The species is virtually silent by day during migration, so watch for their distinctive long, slim shape and rapid, fluid wing beats as they cross over open patches below treetop level on their way from one wood area to another. In fall, areas with fall webworm infestations often support yellow-billed cuckoos.

Now, the western population of the yellow-billed cuckoo will be protected as a threatened species under the Endangered Species Act (ESA), the U.S. Fish and Wildlife Service announced today.

The Service determined that listing a distinct population segment (DPS) of the bird in portions of 12 western states, Canada and Mexico is warranted. In the U.S., the DPS will cover parts of Arizona, California, Colorado, Idaho, Nevada, New Mexico, Texas, Utah, Wyoming, Montana, Oregon and Washington.

The western population of the yellow-billed cuckoo (Coccyzus americanus), is found along creeks in woodland areas, winters in South America and breeds in western North America. Once abundant in the western United States, populations have declined for several decades, primarily due to the severe loss, degradation and fragmentation of its riparian habitat.

 “While the major threat to yellow-billed cuckoos has been loss of riverside habitat, we do not anticipate any significant new water-related requirements as a result of this listing decision,” said Ren Lohoefener, Director of the Service’s Pacific Southwest Region. “The water resource requirements for riparian habitat are not unique to cuckoos, and in many cases are already being implemented for other species.”
Courtesy: Dan Pancamo

The Service’s final listing rule will become effective Nov. 3, 2014.

Here's a video glimpse of this increasingly rare bird species: