On Friday, May 1st, I did a biking big day in Yolo county, starting at 3am from my house in Davis and finishing at 8:10pm back at home, after looping out to Babel Slough, north to Woodland, and back to Davis. In total I biked about 91 miles, seeing/hearing 139 species in total, while drinking 7.5 liters of water. (Approximate route: https://ridewithgps.com/routes/32512864)
For some context, there are two higher biking big day records for the county. A valley floor effort with 145 species (Keith Bailey, Frank Fogarty, and Jason Riggio; 4/25/2018), and a route that included foothill birds that hit 158(!) species (Keith Bailey, Frank Fogarty, Eric LoPresti, and Jason Riggio, 5/2/2018).
Below is a longer description of the day.
I left my home in South Davis at 3am, quickly added a local Western Screech-Owl. Biking over to CR 30B, I heard both Barn and Burrowing Owls. From here I headed east to the causeway over to West Sacramento. On the other side, a stop at Bridgeway Island Pond added a few ducks and shorebirds, including a nice Northern Pintail in silhouette. In the time between 4:45 and 5:30am, I slowly biked south down Jefferson Blvd, heading to Babel Slough. A field full of night-singing Horned Larks was a treat, and listening at a few marshes offered Common Gallinule but no rails (Virginia Rail would be a stinker all day). At 5:30am I reached Babel Slough Road.
Babel Slough was a crucial leg of the day, as it was my one and only real spot to find migrating songbirds. I approached it by birding up and down the road multiple times; once before dawn to catch early bird calls, then for the early arrivals around 7am, and finally a slow pass from NE to SW starting at 8am to work through feeding flocks. It was a good morning! SWAINSON’S THRUSHES were abundant — I heard 5 calling birds before dawn but ended up seeing/hearing about 15 in the daylight hours here. In keeping with the late migrant theme, Yellow Warblers were abundant, and several trees were overflowing with Western Tanagers. A WRENTIT call bounced from a thicket. Nice, this is a crucial specialty bird here. An OLIVE-SIDED FLYCATCHER was one of my first visible songbirds, and there were 4+ WESTERN WOOD-PEWEES along the road. 1 CHIPPING SPARROW gave a few bouts of its long, dry trill from a valley oak.
Other than that, I picked up birds in ones and twos: Townsend’s, Hermit, and Orange-crowned Warbler, Blue Grosbeak, Green Heron, Belted Kingfisher. A White-tailed Kite was a nice find — they can be tricky in late April and early May when they’re nesting. A PEREGRINE FALCON blasted by over the fields to the north. An unexpected bonus was a flyover LONG-BILLED CURLEW! My biggest miss here was Cattle Egret. I had several flyover flocks during scouting, but all my flyovers on this day were Snowy and Great. I also missed Cassin’s Vireo, as well as Black-throated Gray, Yellow-rumped, and Nashville Warbler.
I left Babel Slough at 9:01am with 99 species. An auspicious start! As I worked back up to the causeway, I systematically checked the fishing access points onto the Deep Water Ship Channel, finding 5 CLARK’S and 2 WESTERN GREBES. Reaching Bridgeway Island Pond in daylight, an OSPREY passed over with a fish. 2 CASPIAN TERNS roosted on an island, and CINNAMON and BLUE-WINGED TEAL were swimming. Uh oh, I didn’t see the Northern Pintail that I had noted by shape alone in the predawn hours. Could I still count it? Luckily, I would find another male at Yolo Bypass, ending any lingering doubt about whether a floating silhouette was a good enough identification. Nothing new on my ride along the ship channel levee. I finally arrived at some trees again on the trail just east of the underpass under the Lake Washington/Industrial Blvd bridge. A shady bench called my name. As a sat and chugged water, a single bird flew onto a low branch in a valley oak — my first YELLOW-RUMPED WARBLER. That was a lucky save after missing it earlier, and it was surprisingly the ‘myrtle’ subspecies.
Time to ride. I hopped back onto my bike and powered over to the Yolo Bypass (noting two Mute Swans, which I did not count, near the Port of Sac). I rolled into the bypass at 12:05pm with 112 species on the list so far. Sadly, bikes are not allowed here, so I locked up the bike, put on a hat and lots of sunscreen, hefted a scope over my shoulder, and began my six mile loop. 2 hours and 45 minutes later I was back, but with only 8 new species! The bypass was very dry, with limited shorebird and duck habitat. The biggest surprise was a male RUFOUS HUMMINGBIRD that dropped into some mustard along the auto loop before blasting off to the north. It reminded me of the SF Bay Area, where I would routinely see migrant Rufous Hummingbirds on the move on the barren bayshore trails, briefly poking at flowering mustard and wild radish. Other new birds at the bypass included a flock of soaring California Gulls, American Bittern, Sora, Semipalmated Plover, Northern Shoveler, and Northern Harrier.
I left the bypass at 2:48pm, heading next to the Davis Water Treatment Plant. Here I enjoyed some lingering scouted birds including a LESSER SCAUP. A small flock of WESTERN SANDPIPERS worked a small pond, and a SPOTTED SANDPIPER bobbed nearby. Riding up to Woodland, I noted 2 GREATER WHITE-FRONTED GEESE on the pond at the south end of CR 103. (I see that Michael Perrone noted two at Woodland Wastewater Treatment Plant on the same day. Those were not present when I birded there — I bet the birds I saw at CR 103 were this same pair.) A little further north, an AMERICAN PIPIT flew over, filling that little gap on the list.
Swinging over to Rick Gonzales Park in Woodland, the SAY’S PHOEBE was interacting with a few Western Kingbirds. From here I headed to Farmer’s Central Pond, arriving around 4:50. It hosted the lingering AMERICAN WIGEONS, as well as 2f and 1m CANVASBACK, FORSTER’S TERNS, and my first RUDDY DUCKS of the day. Onward to the Woodland Wastewater Treatment Plant, where some nice treats awaited me. These included the lingering COMMON GOLDENEYES, several DUNLIN and RING-BILLED GULLS, a single EARED GREBE and RED-NECKED PHALAROPE, and, crazily, the very first LEAST SANDPIPERS for the day.
It was 5:45pm and I wasn’t sure how much I would gain by hanging around here. Considering this was a solo effort that was not about to break any records, I decided to bike home to Davis and help put my daughter to bed. I arrived home at 6:45pm, with a list of 138 species. A half-dozen books and a bottle of milk later, I left the house at 7:05pm to slowly bird Willowbank Ditch. I failed in my search for the local (presumably breeding) juncos, and didn’t find any late Red-breasted Nuthatches. However, one new species did fly over. A flock of 7 pipping WHIMBRELS passed overhead — my first at Willlowbank Ditch. Things were getting quiet, and migrants were not easy to find. Only a Swainson’s Thrush and a Yellow Warbler revealed themselves, so I called it quits at 8:10pm to eat, lie down, and give my eyes a rest.
Overall, it was a fantastic day! The songbird migration was solid, and there were plenty of lingering ducks. The biggest weak spot in my effort was shorebirds, due to poor conditions in the county. I missed Acorn Woodpecker and Northern Flicker, a few warblers, and the late sparrows like Fox, Lincoln’s, and White-throated. Virginia Rail was also nowhere to be found.
I’m looking forward to trying a foothill route next! Ideally with some company; you can only talk to yourself so much before you start to feel crazy.