[SBB] 4/22/06 Varied Twitchers Big Day

[[[email protected]] (Mike Rogers)]

All,

Yesterday 4/22/06, Grant Hoyt, Dave Kutilek, Mike Mammoser, Bob Nansen, and I (the 2006 Varied Twitchers) did a Santa Clara County Big Day as part of the SCVAS spring birdathon fundraiser. The weather was not perfect, but at least we did not have last year's morning rain. We did not find any big (or even 
medium-sized) flocks of migrants all day, and the rarest/most surprising bird we found was the white-striped WHITE-THROATED SPARROW that was still with the sparrow flock behind the old cannery building at the Alviso Marina, but we ended up with our best total yet: 165 species! This was made possible by some good luck with uncommon species that can be really tough to locate under the time pressures of a Big Day.

We started out at the Mountain View Forebay, where I arrived just after the 
others had seen a BARN OWL (no matter, we had more later at the EEC and Alum Rock Park). We managed to elicit responses from both SORA and VIRGINIA RAILS before departing for Monte Bello Open Space Preserve. The weather was nice by the bay, but when we stepped out of the car at the start of the Canyon Trail we were greeted by a cold wind and mist - not good for owling. And indeed owling was not that successful until shortly before first light, when we finally managed to tally 4+ WESTERN SCREECH-OWLS and 2 GREAT HORNED OWLS. The first of two NORTHERN PYGMY-OWLS started calling at 6:04am and shortly after that we began our ascent towards Black Mountain.

The dawn chorus was weak and few birds were singing - not good for a Big Day, where rapidly adding singing species is key to success. But with perseverence we added resident birds and recently arrived breeding birds. Critical species that we would likely find nowhere else were added one by one: WINTER WREN, BROWN CREEPER, PURPLE FINCH, BLACK-THROATED GRAY WARBLER (6), PILEATED WOODPECKER (likely two birds, very vocal from 6:36am to 7:20am), BAND-TAILED PIGEON, and PYGMY NUTHATCH. We added 4 lingering RUBY-CROWNED KINGLETS and 2 HERMIT THRUSHES, species not found later in the day. But sparrow numbers were very low, with just a few GOLDEN-CROWNED SPARROWS noted - and migrant flocks were non-existent. We found no tanagers, no migrant Dendroica warblers, and no empids other than a single PACIFIC-SLOPE FLYCATCHER.

At least with so few birds to see we were back at the car ahead of schedule, 
something that has not happened ever before! On the way down the mountain we stopped along the road at a spot that was productive last year. Sure enough, it was great again this year. We added VAUX'S SWIFT, CEDAR WAXWING, a PEREGRINE FALCON, and 3 RED-SHOULDERED HAWKS. Near I280 we picked up NORTHERN ROUGH-WINGED SWALLOW and WHITE-THROATED SWIFT.

We arrived at Stevens Creek County Park at 9:42am, and quickly added new 
species: WILSON'S WARBLER, WESTERN WOOD-PEWEE (3+), and WARBLING VIREO. The Villa Maria picnic area held our biggest migrant flock of the day: 3 AUDUBON'S YELLOW-RUMPED WARBLERS. In a repeat of last year, the day's only WOOD DUCK (a male) flew over the picnic area. We search up to the dam for Blue-gray Gnatcatcher but had no success and used up 45 minutes without adding any species of significance, although 2 more VAUX'S SWIFTS were nice. Driving by the reservoir we added 3 CASPIAN TERNS - and by the upper end of the reservoir we added the day's only CASSIN'S VIREO, WESTERN TANAGER, and BELTED KINGFISHER. We also added an OSPREY, one of the two seen at the reservoir on our drive out, and another VAUX'S SWIFT. The road to Camp Costanoan added DOWNY WOODPECKER and SHARP-SHINNED HAWK and we all managed to see a DIPPER upstream from here.

Thanks to our failed gnatcatcher quest, we arrived at McClellan Ranch 45 minutes behind schedule. A quick search here added our target species: a male HOODED ORIOLE and a WHITE-BREASTED NUTHATCH. We also glimpsed a COOPER'S HAWK busting up a STARLING party.

>From there it was on to the Palo Alto Baylands, where our tardiness meant the 
yacht harbor basin was already drained. But the tide at the yacht harbor mouth was perfect and we quickly added SEMIPALMATED and BLACK-BELLIED PLOVERS, both DOWITCHERS, CLAPPER RAIL, CLARK'S GREBES (plus other Aechmos too distant to ID), another PEREGRINE FALCON (adult), and 4 healthy SURF SCOTERS (as opposed to the 7 seen later at Shoreline Lake). Many species of DUCKS, HERONS, SHOREBIRDS, and GULLS quickly boosted our total further, and we rapidly passed through the hundred species mark shortly after noon.

The duck pond had both SCAUP, at least 2 WHITE-CROWNED SPARROWS with 14 GOLDEN-CROWNED SPARROWS, and the 2 male NORTHERN PINTAILS with injured left wings (we later had healthy pintails at New Chicago Marsh). Geng Road had hundreds of people for "Play at the Bay", so we left after a quick check of the golf course pond.

A flyby GREAT BLUE HERON seen by only two of us at Emily Renzel wetlands was nearly our only one of the day! A quick stop at the Palo Alto Flood Control Basin added the day's only WHITE-TAILED KITE. We circled the Mountain View Forebay, checking Shoreline Lake, Salt Pond A1, Charleston Slough, and the Flood Control Basin in 50 minutes, adding several new species including a GREEN HERON, TREE SWALLOWS at the A1 nest box, 31 BLACK SKIMMERS, 5 AMERICAN WHITE PELICANS (Salt Pond A1), a COMMON MOORHEN, and 3 AMERICAN WIGEON.

Next stop Alviso, where we added 2 BURROWING OWLS by the driving range on the way into town. Salt Pond A8 had 2 SNOWY PLOVERS and a dozen EARED GREBES. The brush by the Alviso Marina and the old cannery building added a FOX SPARROW and the previously noted WHITE-THROATED SPARROW with several of both CROWNED SPARROWS.

Fancy plumaged BONAPARTE'S GULLS were at the pond at State and Spreckles and we added a single WHIMBREL at Arzino Ranch, along with our second COOPER'S HAWK. The salt ponds near the EEC added HERRING (4) and GLAUCOUS-WINGED GULLS (20), as well as 2 WESTERN GREBES and the above-noted BARN OWL. The drive east on Highway 237 added the day's only LOGGERHEAD SHRIKE.

Heading up to Ed Levin Park, we heard a singing RUFOUS-CROWNED SPARROW in the old quarry along the road. A scope stakeout at the northeast corner of Sandy Wool Lake added ALLEN'S and RUFOUS HUMMINGBIRDS, including a year-old male RUFOUS HUMMINGBIRD that had a nearly completely orange back but very little gorget yet (like the 14 Feb bird shown in photograph 23.9 on page 197 of Steve Howell's "Hummingbirds of North America", although even slightly less advanced despite being two months later!) At least 4 female SELASPHORUS HUMMINGBIRDS were here as well. We also added YELLOW-BILLED MAGPIE and WESTERN KINGBIRD before heading up to the sycamores above the lake. Here we added the day's first HOUSE WREN and more RUFOUS-CROWNED SPARROWS before I headed upslope to search for Grasshopper Sparrows. While upslope, I flushed up a LINCOLN'S SPARROW, another species added to the nearly double-digit total of birds not seen by all members of our group (we were in danger of having our total reduced
 by the ABA's 95% rule!). I did manage to flush up a GRASSHOPPER SPARROW and noted where it landed until the others were in place - I then flushed it again and while the others saw it, they felt it was only good enough for "sparrow sp" :(. At least the 6 WILD TURKEYS on the golf course proved to be less of an ID problem.

Elsewhere at Ed Levin Park we added 2 LONG-EARED OWLS and a flyover LAWRENCE'S GOLDFINCH. The row of eucalyptus along the golf course at the Elm Picnic Area had more SELASPHORUS HUMMINGBIRDS and a possible female Black-chinned Hummingbird. I heard the call notes of a LARK SPARROW - another species not shared by the group. :(

Moving on to Calaveras Reservoir, we found BUFFLEHEAD (12+) and RING-NECKED DUCK (33+), WESTERN (and probably also CLARK'S) GREBES, as well as many ducks, including a pair of AMERICAN WIGEON. Another COOPER'S HAWK flew by with prey.

With many of our party still needing Great Blue Heron at 6:30pm!, we headed down Marsh Road to the heronry there, passing a BOBCAT along the way. Several GREAT BLUE HERONS were around, including some bringing sticks to nests. Five YELLOW-RUMPED WARBLERS here constituted a veritable migration bonanza. At the end of Marsh Road, we added a GOLDEN EAGLE, another LARK SPARROW (a distant singing bird that provided fleeting views as it flew off), another WESTERN KINGBIRD, and a male LAZULI BUNTING that headed north after flushing out of the vegetation by the side of the road.

Sierra Road was closed, but we managed to get to the summit, only to find no Horned Larks. Another GOLDEN EAGLE was perched on a high tension tower near here though. Coming back by the summit a second time, we finally added a single HORNED LARK at 7:34pm - it was already dark enough that we seen the first of 5 GREAT HORNED OWLS out hunting! Back to our rock outcrop near Calaveras and Felter Roads, we added 2 ROCK WRENS at 7:56pm, where we had detected none earlier. Incredibly, our shared total problems began to evaporate, as we all got nice looks at a singing LARK SPARROW atop a post,
found another LINCOLN'S SPARROW in the brush and then, at 8:05 pm, located a singing GRASSHOPPER SPARROW just up the road. Our shared total species problem was cured, as everyone had seen or heard 161 of the species on our total list of 165!

In an attempt to add to our total, we taped for Common Poorwill below Ed Levin Park and at the Penitencia Creek entrance to Alum Rock Park. We did add another BARN OWL at the latter spot, but decided to call it a day rather than head for Loma Prieta to get poorwill and Saw-whet owl.

This is the fourth year that the Varied Twitchers have birded this route in spring. In previous years we have found rarities such as Hammond's and Dusky Flycatchers, Nashville and Hermit Warblers, and Lapland Longspur. Yet in the past three years our totals have reached 157, 158, and 157 species. This year we did signficantly better, without good migrant flocks or super-rarities, just by having good luck with uncommon birds such as Osprey, Green Heron, Belted Kingfisher, Downy Woodpecker, finding both accipiters, both Aechmophorus grebes, both Selasphorus hummingbirds, all three rails, etc. I wonder how well we could have done with some migrants added into the mix!

Mike Rogers

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