The efforts of about 130 bird-watchers last weekend resulted in one of the most diverse species observations on record.
According to the San Diego Audubon Society, 35 teams of volunteers spread across a 15-mile-wide circle centered on Sweetwater River, running from Sweetwater Reservoir in Spring Valley to the Tijuana River Valley, Trolley Barn Park in North Park, and up to five miles off the coast on December 19.
Participants in the society's annual Christmas bird count recorded observations of 220 different species, up from 209 last year and clocking in with the fourth-most-diverse count of 2400 recorded in the Western Hemisphere.
"We know bird populations respond to changes in our climate — we’ve watched the winter range of hundreds of bird species move nearly 40 miles to the north in just the past 50 years," said society executive director Chris Redfern in a December 22 release announcing the count results. "The Christmas Bird Count helps us recognize such trends, collect data, and better understand the effects of climate change so we can prioritize local conservation efforts to match."
The group says that it believes climate change threatens or will threaten as many as 314 bird species in North America.