Date: 5/5/25 9:55 am From: Robert Furrow via groups.io <robertfurrow...> Subject: [centralvalleybirds] Yolo county big day, 1 May 2025, 173 species (long)
On May 1st, 2025, Zane Pickus, Danny Karp, Jason Riggio, and I did a big
day in Yolo County. We finished the day with 173 species, one species
higher than the previous county record of 172 set a quarter-century ago.
Big days require a careful analysis of bird status and distribution, and
they always teach you a lot about the area you are covering and how things
are changing. This prior record was an incredible effort with very few
misses, but we hoped that some shifts in birdlife in Yolo would give us a
shot: abundant Great-tailed Grackles and Eurasian Collared-Doves,
increasing numbers of Least Bittern, and a recent pattern of diverse late
spring ducks at the Woodland Water Treatment Plant. We also had great
scouting. Zane Pickus and Emmett Iverson had completed a big day just two
days earlier, so Zane had the skinny on many good birds, and many others
shared helpful bird info. Thanks so much to Emmett Iverson, Julian Johnson,
Lynette Williams Duman, Tom Uslan, Chris Dong, Kelli O’Neill, Sean Smith,
and Bart Wickel for help with site access or information about stakeout
birds. The full eBird trip report from our day is here:
https://ebird.org/tripreport/359820
We elected to use no audio playback for this big day; we did not use a
speaker to play the songs of any target birds. Sparse and thoughtful
playback is unlikely to cause harmful long-term impacts to birds, and is
commonly used in California big days, but we were curious to see how much
things would change if we skipped it. We suspected that we might suffer the
misses of a few secretive birds, but we also wondered if there would be
some positives to more quiet listening and less time fiddling with phones
and speakers. We still occasionally pished, squeaked, and whistled, but we
mostly just tried to find what was around and active at each site.
We kicked off the morning at 1:30am, working through a series of wetland
and grassland patches near Davis. American Barn Owl was our first bird,
soon followed by Marsh Wren, Tricolored Blackbird, Virginia Rail, and American
Bittern. A different patch hosted Sora. We then headed towards Capay, after
a brief stop in Woodland. Near the Capay Bridge we delighted in a flying Lesser
Nighthawk along Cache Creek. At 3:40am we packed our backpacks with morning
snacks and began to hike up Rayhouse Road. Great Horned Owls called from
the lower section and a Western Screech-Owl eventually bubbled from above
us in blue oak woodland, but no pygmy-owls were tooting. At least those
frequently pop up in the daytime. We started to get nervous about missing
Common Poorwill, so we picked up the pace and reached the first patch of
chamise chaparral around 5:10am. 15 more minutes of walking and still no
poorwill, even in patches where they are relatively dense. Black-headed
Grosbeaks, Bell’s Sparrows, and Spotted Towhees sang in the calm air. Were
we too late? Thankfully, a distant Common Poorwill sounded off at 5:30am,
followed by several more for the next 10 minutes. A Northern Pygmy-Owl also
released a series of toots, but was not heard by the full group – a ‘dirty’
bird for now.
The dawn chorus rolled on in waves. After the initial burst at 5:30am,
activity lulled until the next crescendo as sunlight actually hit the
slopes. The most important dawn birds for this route are chaparral species
and fairly localized birds that are hard to find when the day heats up; we
heard Mountain Quail, Rufous-crowned Sparrow, Lark Sparrow, California
Thrasher, Wrentit, and Blue-gray Gnatcatcher. Overhead several Lawrence’s
Goldfinches tee-teed, a single Purple Finch ticked, and a modest flow of
ridge migrants began just as the sun hit the east-facing slopes. These
included many Western Tanagers, plus Lazuli Buntings, Black-headed Grosbeaks,
and Rufous Hummingbirds making very brief stops at paintbrush flowers
before rocketing northward. Warblers were well represented: Townsend’s,
Hermit, Black-throated Gray, Yellow-rumped, Wilson’s, Yellow, and
Orange-crowned. An unseen braying Swainson’s Thrush on a brushy slope was a
nice surprise. Dropping back into the blue oak woodland, Danny spotted
a Band-tailed
Pigeon, while Jason cued the group in on a Hammond’s Flycatcher and our
first Warbling Vireo. We found only a single Nashville Warbler, and the
downhill birding was fairly slow, punctuated by Hairy Woodpecker,
White-breasted
Nuthatch, Violet-green Swallow, and a singing Western Wood-Pewee detected
only by Rob. Although pygmy-owl started as a dirty bird, we heard several
more on the way down and even got to see three different individuals- one
that flew up into a tree right next to us and then another two on a branch
next to the trail! Rayhouse had one more good bird in a store, a late
Sharp-shinned
Hawk winging over a hilltop fairly close to Cache Creek. Crossing the high
water bridge, Danny got us on a Downy Woodpecker, which would be our only
one of the day.
Although it was a solid morning on Rayhouse, we had enough misses that we
believed the record of 172 was likely out of reach. Steller’s Jay, Pileated
Woodpecker, and Hutton’s Vireo are now gone or extremely sparse there, and
we also missed Western and Olive-sided Flycatcher, Cassin’s Vireo, Hermit
Thrush, Dark-eyed Junco, as well as any special bonuses like Calliope
Hummingbird, Ruby-crowned Kinglet, Chipping or Black-chinned Sparrow,
MacGillivray’s Warbler, Yellow-breasted Chat, or the recently noted Pine
Siskin. We headed out. Scouting had turned up locations for both Canyon and
Rock Wren in Cache Creek Canyon, but none sounded off at 9:30am. Two more
misses. Using playback might have helped here, but who knows for certain?
Just as our energy waned, we had a new set of rewards. A Loggerhead Shrike flew
by as we left Rumsey, then a male Phainopepla landed right on the median of
Highway 16. A stop at Vernon Nichols County Park was quiet, but the west
end of CR 81 had good surprises. A pair of Golden Eagles circled over the
hillside, and just as we were about to pull scopes to check distant snags,
a Lewis’s Woodpecker looped out of the crown of a nearby oak. Bonus! There
had been no Lewis’s on the route during scouting. With the Capay Valley
birds well-covered, we headed directly to Capay Open Space Park. We scoped
the quarry pond and found Eared Grebe but not much else, and no migrants
were evident along the creek. After a quiet stop at the Esparto Water
Treatment Plant, we hit the CR 94B bridge over Cache Creek. Zane pulled Bank
Swallows out of swirling swallow flocks, and Danny found the day’s only Belted
Kingfisher on a distant perch.
Reaching Woodland, we benefitted massively from Zane and Emmett’s recent
big day. We made a quick stop for Say’s Phoebe to avoid potential issues
with the nesting Davis birds, then surgically scanned the Woodland Water
Treatment Plant ponds. Most of the stakeouts were right where Zane expected
them. Horned Grebe, Northern Pintail, and Common Goldeneye all appeared
within a minute, two Greater White-fronted Geese surprised us, and we had
no trouble finding Bufflehead, Canvasback, Redhead, and Lesser Scaup. On
the south side we hustled along the western berm to pond 4 (the 4th small
pond from the north in the western “column”), where Ring-necked Ducks
continued,
American Wigeons abounded, and a pair of Red-necked Phalaropes frantically
poked around. As we continued a lap of the southern Water Treatment Plant
ponds, late American Pipit bounced off the levee, Spotted Sandpipers flushed,
and a pair of Wilson’s Phalaropes zipped past. Just as we returned to the
car, a Green Heron flew over us heading towards the North Regional Pond.
Belted Kingfisher and Green Heron can both be real stinkers on a big day,
so it was a relief to have found them both without extra time or effort.
It was 2:00pm and new birds now came only in a trickle. A Wild Turkey crossing
CR 103. A flock of California Gulls in the main landfill pond. We also
turned up a Mute Swan, but this bird still doesn’t count towards Yolo big
day totals (despite its ever increasing population in California’s Central
Valley). We did, however, spot soaring American White Pelicans
overhead and Brewer’s
Blackbirds by the Davis Water Treatment Plant. We had a small but important
set of targets within the city of Davis, so we crossed our fingers as we
entered North Davis. Hooded Oriole in a California fan palm was quick, but
a tip about a Cooper’s Hawk nest did not pay off. We stood by a pine with a
regular Red-breasted Nuthatch, but the time of day combined with a man
literally leaf blowing the base of the tree made for an unproductive visit.
These misses, along with our lack of a junco on Rayhouse, necessitated a
stop at Willowbank Ditch. It worked! The late-staying Red-breasted
Nuthatch gave
a nasal trill while a Dark-eyed Junco sang consistently. Moments later
Danny spotted a Cooper’s Hawk circling overhead. We used 10 more minutes to
look for migrants. An Empidonax flycatcher got us excited, but oddly enough
it was another Hammond’s rather than the hoped-for Western.
Because warm afternoons can be slow during big days, it’s a treat whenever
there’s a productive hotspot coming up. At 4:10pm we reached the Yolo
Bypass Wildlife Area. Our duck list was excellent, but given that we still
had many songbird misses we assumed a strong finish to the day would get us
to a total of around 165 species. As we worked the auto loop, we found what
we needed: Greater Yellowlegs, Ring-necked Pheasant, Horned Lark.
Then magic happened. Three Snow Geese loafed by lot H, and the shorebird
fields to the north hosted almost every bird we were still missing. Jason
whisked out a single Dunlin, and we quickly found the expected Semipalmated
Plover, Long-billed Curlew, and Whimbrel. More surprising were Zane’s
pick-ups: Green-winged Teal (missed stakeout in Woodland) and two Black-bellied
Plovers (very scarce here by May 1st). Danny scoped the trees to the east
to eke out distant Osprey and White-tailed Kite. We hopped back in the car
for a quick ride to Lot G. No luck with migrants or lingering White-crowned
or Lincoln’s Sparrows. However, as I took out my contacts and switched to
glasses, my blurry eyes came into focus on a Peregrine Falcon powering
through the wind, perhaps hungry for the many dowitcher flocks moving
around. Somehow the bypass had even more in store. A check of the trees at
the “Y” had only two migrants lurking, but they were a Ruby-crowned Kinglet and
a Western Flycatcher!!! Moments later, one of the closest shorebirds on the
exit road was a bobbing Solitary Sandpiper, appearing just moments after
Zane reminded us to watch closely for one.
Now the adrenaline was flowing. The record had seemed clearly out of reach,
right up until we found a half-dozen unexpected birds at the bypass. We
realized that our total was currently 165, only 8 birds away from breaking
the record. And we knew we had at least two reasonable after-dark birds.
Could we find 6 more daytime birds in the final 2.5 hours of light in West
Sacramento? That sounded very reasonable until we realized that pretty
much all of the common birds were already on the day’s list. Still, we had
some ~20 possibilities remaining that were not totally improbable.
First up, Bridgeway Island Pond, famous for its regular and often
abundant Blue-winged
Teal. Yep, some of the first birds we glassed were a pair of them! 166. Now
for the Caspian Terns that love the Deepwater Shipping Channel. Easy,
right? Right? Nope. No Caspian Terns here today. Nor Common Merganser.
Well, we had several more spots to scan along the channel. Working south, a
check of the Bald Eagle nest tree showed no visible birds. Just as we
started to worry, an adult Bald Eagle flew past. 167. Still no Caspian Tern
or Common Merganser. Another channel check. Two White-crowned Sparrows
flushed up! 168. But nothing new in or over the water. Perhaps there would
be terns over Pumphouse Lake? Nope. However, Zane finally spotted our
first Northern
Harrier. 169. We couldn’t believe it had taken so long after a half-day of
intense birding in their habitat. With our extra effort along the channel
we didn’t have time to check Babel Slough spots for Blue Grosbeak or
missing migrants, so we continued southward.
We had an ace up our sleeve for the end of the day. Zane had contacted Tom
Uslan a week earlier, and Tom generously invited us to visit his house.
Tom’s property has an ever-rotating cast of amazing rare birds, as well as
the most productive hummingbird feeders in Yolo County. Although 7:30pm
wasn’t the ideal time to take advantage of his impressive native
landscaping for songbirds, it was a very good time for feeder-watching. We
immediately found many Black-chinned Hummingbirds. 170. It took a little
longer, but the regular male Allen’s Hummingbird eventually made several
visits. 171. Tom informed us that multiple Calliope Hummingbirds had been
on the property earlier in the day, as well as multiple Lincoln’s Sparrows.
Despite a focused effort, neither of those species appeared for us. In the
final stages of civil twilight, we thanked Tom for allowing us access to
his private property and piled back into the car. We stopped for a final
glimpse at the Deepwater Shipping Channel but ultimately resigned to
missing Caspian Tern. This was our biggest miss of the day, followed
perhaps by Cassin’s Vireo. When those are your biggest misses on a big day,
things have gone well!
One nighttime species would tie the record, and two would break it. We had
three possibilities remaining. Least Bittern sounded off quietly at a pond
in West Sacramento. 172; we had tied the record! Now for some driving. With
tired eyes but high spirits, we made the long drive over to Davis then
south to the southwestern edge of the county, in proper “delta” habitat. We
briefly entered Solano County so that we could drive on paved roads for
part of the journey. Would we be able to find Burrowing Owls on a windy
night without any playback? Yes! After an anxious drive down the road, and
an even more anxious walk down the road, a Burrowing Owl pair fluttered
over a field. 173! With the record broken and high fives all around, we
hoped to pad our list with the final possibility. 10 minutes to the north
was a Grasshopper Sparrow territory. We quietly listened, but mostly heard
the strong whistling wind while we shivered. No luck. We decided to end
with a total of 173 species, and drove back to Davis.
Reflecting on the full day, here are some highlights, lowlights, and
take-aways. Our bird highlights were many: seeing so many Northern
Pygmy-Owls in the daytime, a surprise Lewis’s Woodpecker, incredible
diversity at the Woodland Water Treatment Plant (including a late alternate
Horned Grebe), fantastic birding at the Yolo Bypass Wildlife Area, and the
cooperative Allen’s Hummingbird at Tom’s place. We had only a few dirty
birds not seen or heard by the full group: American Bittern, Red-breasted
Nuthatch, Western Wood-Pewee, and Yellow Warbler.
Another highlight was the lack of traffic or other unexpected issues. Even
the drive from the Yolo Bypass to West Sacramento was essentially
traffic-free. Sometimes big days also lead to strange encounters; groups of
running, wild-eyed, binocular-clad strangers on a remote road or trail can
shock local folks. But we ran into no issues except a brief odd chat with a
man standing over a deceased vulture. As a friend put it, our biggest
challenge was that “we almost talked to a guy”. For lowlights, there were
really none, though it is disappointing to see the loss of some of the
foothill woodland birds on Rayhouse Road. However, those birds may return
as the area continues to regrow… until the next fire.
Every big day has its share of misses, and ours was no exception. Species
seen during scouting or in the days immediately after the big day included
Cackling Goose, Lesser Yellowlegs, Marbled Godwit, Snowy Plover, Caspian
Tern, Black Tern, Olive-sided Flycatcher, Cassin’s Vireo, Rock Wren, Canyon
Wren, Hermit Thrush, Pine Siskin, and Grasshopper Sparrow. Other species
that felt possible include Common Merganser, Wilson’s Snipe, Bonaparte’s
Gull, Western Cattle-Egret, Chipping Sparrow, and Fox Sparrow. These birds
lead us to imagine that a higher record, perhaps in the high 170’s, may be
possible. However, given our stakeouts, preparation, and incredible luck on
the day, this would take an extraordinary effort.
For other take-aways, we were pleasantly surprised that we could break the
record without using any playback. Yes, we left the Rock and Canyon Wren
territories suspecting that playback would have made them a near-certainty,
and the Grasshopper Sparrow probably could have been coaxed into a few
bouts of song if we had stirred its competitive spirits with the song of a
different male. But that’s not a lot of misses, and it’s more fun to be in
the thick of birding without unleashing loud bouts of speaker noise. From a
perspective of bird welfare, there isn’t a substantial body of
peer-reviewed evidence that playback causes long-term problems, and it may
be only marginally different from the impact of humans simply being in a
bird’s habitat. So we share this not as an indictment of careful playback,
but as a nice example that playback may not be integral to a
record-breaking big day attempt.
What about the date and route? We discussed it a lot throughout the day and
concluded that we couldn’t imagine any better way to optimize. On May 1st
you can find pretty much all the birds that you might find on April 20th
(except perhaps Fox Sparrow), but many passage migrant songbirds become
more likely on the later date. Although shorebird numbers in Yolo may peak
in the second or third week of April, the potential for phalaropes and
bonus oddities is higher in early May. This all worked out for us; we
found almost the entire gamut of expected duck and shorebird diversity
while also taking in a wide diversity of migrant songbirds. So, why not go
even later? Well, the shorebirds and ducks get much harder very quickly,
and a few more sparrows fall off the map (White-crowned, Golden-crowned,
Lincoln’s). May 1st, plus or minus two days depending on weather
conditions, seems to thread the needle just right. We also felt like the
route was optimal. Starting high up on Rayhouse Road or another higher
elevation chaparral slope is a necessity, both because of the localized
birds found only there and because of the potential for some ridge
migration to quickly find warblers and other passage migrants. Stops
between there and Woodland are debatable based on targets, but the Woodland
Water Treatment Plant is a crucial stop both for the north pond and the
small ponds on the south side. Other key stops include a brief visit in
Davis (for Hooded Oriole, Cooper’s Hawk, Red-breasted Nuthatch) and the
Yolo Bypass Wildlife Area. We liked having West Sacramento and points
southward as the day’s anchor. That area has a range of options depending
on targets: pond and channel habitat, farmland, and riparian strips like
Babel Slough.
Finally, we were all grateful to be part of an energetic, skilled, and
friendly team, supported by a community of knowledgeable, generous, and
active Yolo County birders. Spring migration comes and goes so fast, and
big days provide a marvelous snapshot of this magical period. Happy birding!
-Rob Furrow
--
Robert Furrow
Davis, CA 95618
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