2023-2024 Christmas Bird Count Results

Barry Langdon-Lassagne — Aggregator

Introduction

Every December-January SCVAS sponsors several Christmas Bird Counts (CBCs), part of a citizen science project coordinated by the National Audubon Society. Organizations use data collected in this long-running wildlife census to assess the health of bird populations and to help guide conservation action. Read about how the data is used and about the histories of our counts. Also see our Highlights and tables for past Christmas Bird Counts. For information outside our area, visit Audubon Christmas Bird Count.

Each CBC has the primary goal of counting all individuals of each species of bird detected in a 15-mile-diameter circle on a single day. In the SCVAS counts, each of our four predefined count circles are divided into sectors by the count leader and teams are assigned to count birds in each sector. Counters with less experience are teamed with those more experienced. Even if beginning birders can't identify every bird, they provide important "extra eyes" in finding birds. A countdown dinner is held on the evening of the count, where groups share their results and tell tales of the day.

Latest Results

Below are the results from our four Christmas Bird Counts for this winter. Across our four count circles, 362 volunteers were able to tally 196,476 individual birds spanning 196 species.

View the 2023-2024 TABLE — an aggregation of the results from all four Christmas Bird Counts
(also see previous years’ results)

San Jose

Mike Azevedo, Compiler

The San Jose Christmas Bird Count took place on Sunday, December 17th, 2023. Threats of afternoon rain seemed to affect the birds, and many sectors didn't seem so "birdy.” One hundred and five participants fanned out across the valley to find birds in tidelands and in the hills and parks around Silicon Valley. Rare birds found in the Alviso sector included some favorites that do get seen relatively frequently such as Blue-winged Teal, Eurasian Wigeon, Barrow’s Goldeneye, Black Rail, Glaucous Gull, Red-throated Loon and Swamp Sparrow. Tree Swallows, Violet Green Swallows and Barn Swallows were found, as they have in recent years, but unlike last year, where these fast-flyers were found in several sectors, this year, they were only found around Alviso.

Western Tanager was found in both Santa Clara/Sunnyvale Sector and the Guadalupe River area. Lewis's Woodpecker were seen in the old golf course on Tully across from Lake Cunningham for the Evergreen Sector. Ferruginous Hawk was seen at Calaveras Reservoir by the South Reservoir team. Also seen and written up, Yellow-bellied Sapsucker and Cackling Goose. Agnews sector birders found a Rusty Blackbird, and Nashville Warbler.

Sanderling and White-throated Swift were missed, as was Short-eared, Northern Pygmy-Owl and Hutton's Vireo. Thankfully, Burrowing Owl was not among the missing, a few individuals being found in Calaveras sector at Wool Ranch and East reservoir.

This year, the Young Birders Club participated as a team for the Alviso sector. Alviso generally attracts our best birders and these students and their parents were able to use their solid experience with baylands birding to lend a hand when it was most needed.

Palo Alto

Al Eisner, Compiler

The Palo Alto CBC took place in mostly-wet weather on Monday December 18. The weather created unpleasant conditions, especially for many counting in the Santa Cruz Mountains. While the 146 participants was only a bit below last year's record (160), the effort in party-hours was down about 17% compared to the last two counts, while the total number of birds was more than 25% lower. However, we did manage to find 163 species, only a few less than our recent average.

Because of the weather, it probably isn't useful to conclude much about numerical trends for individual species (last year's very high count of Band-tailed Pigeons, highest in the nation, was back to more "normal" numbers.)  Most of our Owl species stayed undetected, and some species usually found on the count were missed: Greater White-fronted Goose, Wood Duck, Eurasian Wigeon, Ruddy Turnstone, Golden Eagle, Barn Owl, Western Screech-Owl, Pileated Woodpecker, Loggerhead Shrike and Swamp Sparrow.

One new species was found for the count: a CHESTNUT-SIDED WARBLER at Mitchell Park in Palo Alto. A CASPIAN TERN at salt pond SF2 by the Dumbarton Bridge was a second count record, while the CURLEW SANDPIPER, back for its third winter at the Palo Alto Baylands, is still a quite amazing record.  Another third-time species was BLACK RAIL (the previous two were in the 1980's).  Several PELAGIC CORMORANTs have turned up in the count area this winter; one near Redwood Creek was a fourth-time count record. BLACK OYSTERCATCHER has settled in near the Dumbarton Bridge, with a total of 5 found by two parties. Other good finds included a RED-THROATED LOON in the Bay (I'm not sure in which county), 2 OSPREYs near the Dumbarton Bridge, 4 SNOWY PLOVERs in San Mateo County, both TREE and VIOLET-GREEN SWALLOWs in Bayside Santa Clara County, a pair of BALD EAGLEs in Santa Clara Co, a GREAT-TAILED GRACKLE near Byrne Preserve in Los Altos Hills, and a PALM WARBLER along downstream San Fracisquito Creek (seen in both counties).

Thanks are due to our intrepid counters, to our sector coordinators, and to Ann Hepenstal for organizing the count and for setting up our first fully-in-person countdown/dinner since the pre-pandemic era.

Calero-Morgan Hill

Rick Herder, Compiler

At dawn the Calero-Morgan Hill count on Sat., Dec. 30 didn't look promising. There were rain showers during the early hours, the sun never fully came out, and the temperature hovered in the 50s. Nevertheless, a very good turnout of 94 observers probably helped the count total of 143 species, the highest in several years. Several participants had outstanding days. Carter Gasiorowski found a Summer Tanager, a new bird for the count, and also found a Black-throated Gray Warbler. He, and several other counters, also found an Orange-crowned Warbler.

Other reported count rarities were Greater White-fronted Goose, Cackling Goose, Vaux's Swift over Coyote Valley, Lewis's and Pileated Woodpeckers, Violet-green Swallow, and Blue-gray Gnatcatcher along Calero Creek. The Pileated Woodpeckers were reported in a new area for the count, in the hills above Almaden Valley. They've shown up on several recent counts and may be expanding their range east. It’s tough to  be certain about eagle numbers, especially in areas like Coyote Valley where they are seen in both the Diablo and Sierra Azul range foothills as well as over the valley, but Bald Eagle sightings have been growing in the last five years. Golden Eagle counts have been steady.

The relatively high species total for this latest count is especially notable since very few shorebirds or ducks were reported this year - one Greater Yellowlegs and one American Wigeon for example. A single Loggerhead Shrike was discouraging, reports of this bird have been dropping. But the berry crop was abundant this year and so were birds such as American Robin and Cedar Waxwing. We also had high counts of Red-breasted Nuthatch, Common Yellowthroat, Townsend’s and Hermit Warblers. We did have a few misses of expected birds. Janna Pauser quickly found count week Chipping Sparrows that were missed on count day.

Mount Hamilton

Bob Hirt, Compiler

We had our count on Tuesday, January 2, 2024 and we welcomed good weather throughout most of the day. The smaller ponds were open and the water birds were spread out. We had very little weather-related access problems since the roads were open and dry.

Unfortunately, we were not able to get access to one of the key ranches and consequently our numbers this year are much lower and perhaps not comparable. We had a below average species count coming in at 89 species, with only 3,493 individual birds for the day. Some of this due to fewer areas counted and some due to the continued impact of the devastation from the SCU Lightning Complex fires of 2020.

As to individual species we had very low count of Lawrence’s Goldfinches with only 9 tallied. One other target was Lewis’s Woodpecker and we came in at only 7. Bell’s Sparrow came in at 4. Golden Eagles at 9 and Bald at 5 were about normal. We did find 11 Varied Thrushes. Our brave owlers found 8 Screech, 7 Great-horned and a Pygmy Owl.

Thanks to our leaders again: Elinor Gates (and her team: Howard Higley, Howard Friedman, Carolyn Straub and Steve McHenry) Mike Rogers (Mike Mammoser), Mike Azevedo (Bill Walker), and especially, Pete Dunten who solo hiked the grueling Mule trail and stayed into the late day rain, to Kirsten Holmquist and her team (Rich Page and Dale Stahlecker) for the long hike on one of the large ranches, and to Leighton Nakata and Petra Kinsman for counting the birds on the San Antonio Valley Ecological Reserve. I received help again from Dave Stocks and his rugged truck. Our deepest thanks to Elinor Gates for hosting a marvelous compilation feast again this year and for helping count the birds at the top and stocking her house feeders. 

More Information

Read about how the data are used and about the histories of our counts. Also see our Highlights and tables for past Christmas Bird Counts.

If you’re new to the Christmas Bird Count, the writeups from previous years can help you understand what the experience is like! Check out the writeups from previous years including pictures and tables of all birds observed. Here are all the recent writeups:

• 2022-23 CBC Writeups

• 2021-22 CBC Writeups

• 2020-21 CBC Writeups

• 2019-20 CBC Writeups

• 2018-19 CBC Writeups

Banner photo: East side of Mount Hamilton, 2023 Mount Hamilton CBC by Pete Dunten