Date: 12/31/25 2:37 pm From: Samuel Bressler via groups.io <pacificgoldenplover...> Subject: [OrangeCountyBirding] Puente-Chino Hills Christmas Bird Count Results, 2025
All:
The 2025 Puente-Chino Hills Christmas Bird Count took place on Saturday, December 27th in ideal weather conditions, with temperatures in the 50s and 60s, clear skies, and little to no wind. These conditions came on the heels of a massive storm that dropped nearly 5 inches of rain on the region from December 24th-26th; as a result, most of the trail systems through the Chino Hills and Santa Ana foothills were closed, including in Santiago Oaks Regional Park, Weir Canyon Nature Preserve, Gypsum Canyon Wilderness, Powder Canyon, and most of Chino Hills State Park. Additionally, the large amounts of rain meant that the upper reaches of the Santa Ana River had unusually high water volume and flow velocities, reducing habitat for most waterfowl and shorebird species.
Despite these setbacks, the 2025 count smashed the prior record for species diversity on a single count, with a total of 155 species (plus 4 ABA non-countable species) observed over the course of the day. The prior record had been 146+3. Twelve new species for the count were observed, and a wide variety of unusual to rare overwintering species were found or relocated.
For those who wish to review an (almost) final count list, a trip report can be found here: Puente-Chino Hills Christmas Bird Count, 12/27/2025 - eBird Trip Report ( https://ebird.org/tripreport/452535 )
Of particular note were 11(!) warbler species, five of which were new for the count. For comparison, our previous high count for warbler species was 6.
We did not miss many expected species, but the easiest ones were bald eagle (count week) and long-billed dowitcher (difficult following high flow events along the river). Diving ducks were mostly absent, as common goldeneye (present during count week at Walnut Canyon Reservoir), canvasback, hooded merganser, and common merganser were all absent on count day. This is also the first year we have missed wood duck; this species has gradually become quite difficult in this part of the county in recent years. Other notable misses included a count week Vesper Sparrow at Brea Sports Park, northern yellow warbler, green heron, and Wilson’s snipe.
Ironically, the trail closures might have helped increase our species count, as it concentrated efforts in a number of smaller parks that otherwise might not have been covered as intensively. Furthermore, the sports fields within the regional and city parks were closed to recreation and thus lightly trafficked, meaning that they were more heavily used by sparrows, waterfowl and other birds.
Numbers of many species were lower than last year, particularly those found in chaparral and scrub areas that were not accessible (e.g. California quail, California thrasher, wrentit). It was also a poor year for many sparrow species, particularly rufous-crowned sparrow (only 5, vs. 14 last year), Lincoln’s sparrow (only 18, vs. 28 last year), and chipping sparrow (39, vs. 145 last year). On the other hand, the 392 dark-eyed juncos observed were almost double last years count, and the 991 cedar waxwings reported was a genuinely remarkable total. Last year’s 413 Swinhoe’s white-eye was the highest tally across the entire United States, so this year’s increase to 662 means we will likely retain this distinction. It’s remarkable to think that the first count recorded only 2!
As every year, Yellow-rumped Warbler was the most abundant species on the CBC, with 3016 recorded; this reflects a modest decrease from last year’s 3513 species..Other abundant species included house finch (2312), Canada goose (1181), white-crowned sparrow (1152), and American crow (1014). Twenty-one species were represented by a single individual.
I look forward to seeing you at next year's count!
