Fresno ecological consultant Jeff Davis has been studying tricolored blackbirds for more than 20 years.  Davis will present “Tricolored Blackbirds: Preventing Another Extinction” at 7 p.m. Nov. 13 at Oakhurst Methodist Church. The public is welcome. Photo credit: Jeff Davis and Gary Woods

Tricolored blackbirds, a species virtually endemic to California, once numbered in the millions, nesting in enormous colonies that, historically, supported as many as 200,000 nests, the largest breeding colonies of any North American land bird.

Today, tricolored blackbirds, similar in appearance to the more familiar and widespread red-winged blackbird, are in trouble, their population having plunged dramatically within the past several years.  A survey, released earlier this year, led by UC Davis in collaboration with the U.S. Fish and Wildlife Service, the California Department of Fish and Wildlife and Audubon California, estimated a total remaining population of 145,000 birds, a drop of 64 percent since 2008 and 44 percent just in the past three years.

Professional ornithologist and ecological consultant Jeff Davis of Fresno has participated in tricolored blackbird surveys since the early 1990s, personally witnessing their stunning decline, and continues to work actively to reverse that trend and help restore their population.  Davis will be the featured speaker at the November program of the Yosemite Area Audubon Society.  His slide presentation, “Tricolored Blackbirds: Preventing Another Extinction,” will be held Thursday, November 13, 2014 at the Oakhurst Methodist Church on Road 426 beginning at 7:00 p.m.

The colonial habits of tricolored blackbirds have been both a blessing and a curse, producing impressive numbers of young birds in good reproductive years but making them vulnerable to dramatic nesting failures that can destroy thousands of birds when their habitat and feeding requirements are compromised.

As their favored wetland and native grassland habitats have given way to urban development and agricultural conversions, many tricolored blackbirds have adapted by roosting and nesting in some crops, mostly cereal grain and dairy silage fields, where some of the largest colonies today occur.  Often, unfortunately, the grain is harvested before the nesting cycle is completed, killing thousands of blackbird chicks and eggs and causing catastrophic nesting failure.

"Literally, in the span of 10 minutes, 10 percent of the global population of this bird can be wiped out," said Daniela Ogden, a spokeswoman for Audubon California.

Davis is now part of a proactive working group of tricolored blackbird experts and bird conservation activists to expand an incentive program, sparked by YAAS President Lowell Young’s leadership, that pays farmers to protect tricolored blackbird nesting colonies and to restore and enhance former and potential habitat sites.  Jeff’s presentation November 13 will highlight this project; the status of local populations, where to find them and their ecological importance; why they’re in trouble and what we can do--and are doing--to preserve them.  

Along with his efforts to protect and restore tricolored blackbirds, Davis is also a Northern California regional editor for North American Birds, eBird editor for Fresno and Madera counties, and bird records compiler and science advisor for the Fresno Audubon Society.

Like all YAAS programs, Davis’s presentation on November 13 is open and free to the public, although donations to defray program costs and to support the chapter’s local activities are appreciated.

YAAS will also lead its monthly field trip Saturday, November 15, along the route of the local chapter’s LeGrand raptor run in the lower foothills.  Participants should meet at the Mariposa County Fairgrounds at 8:00 a.m. to carpool.  The trip is free and the public welcome.  Bring binoculars, field guides, lunch and beverages. 

Call (209) 742-5579 or (209) 966-2547 or visit: www.yosemiteaudubon.org for additional information about either the program or the field trip.

The mission of the National Audubon Society, the namesake of noted 19th-century naturalist and bird painter John James Audubon; its state affiliate, Audubon California; and local chapters such as the Yosemite Area Audubon Society is to conserve and restore natural ecosystems, focusing on birds, other wildlife and their habitats for the benefit of humanity and the earth’s biological diversity.  The YAAS is dedicated to educating and inspiring others to help protect those resource values.

Article contributed by Len McKenzie