Hi all,
I, too, undertook a marathon birding tour yesterday. For me, eBird's Global Big Day was a great excuse to attempt a local effort based around local Boulder County locations. All told I ticked 140 species, hiking over 20 miles and driving just over 100 in an area under 88 square miles.
Some serious effort was put in to detect night birds, with mixed results. A flat tire on my bike at 2 am, miles from the car with the rain starting to come down, put a small damper on things. By dawn moral was high and the birds poured in. Birding in the foothills was much more challenging than usual, mostly because of the cool, wet conditions. Most breeding species are just barely back on territory, and even those which are were not singing much. A week from now and the same birds, plus some, could be detected in 2/3 the time.
Soon, I discovered that most of the birds were simply 100 ft lower down by South Boulder Creek. At the South Mesa Trailhead I gathered up a good smattering of species which should be filling out the nearby foothills habitat as soon as the sun comes back out, things like Hammond's Flycatchers, scads of Virginia's Warblers, and some Plumbeous Vireos. The highlight of that stop, and the day really, was a smacking adult Black-throated Blue Warbler.
Further along South Boulder Creek I picked up some more migrants like Least Flycatcher and Northern Waterthrush. An Eastern Phoebe was on territory, as expected, but unfortunately the Bobolinks have yet to return to the hay fields near the creek.
The afternoon was spent picking off ducks, a few shorebirds, and stake-outs like the Boulder Creek Black Phoebe. A last-minute stop at the seasonally flooded pool near Jay and the Diagonal produced a surprise Long-billed Curlew and Franklin's Gulls. In the evening, I hiked up Skunk Canyon and found the Rose-breasted Grosbeak and
Ovenbird.
The conditions were a plus but also a minus. Many common breeding birds just weren't back on territory, things like Bobolink, Cordilleran Flycatcher, and Grasshopper Sparrow. The spring storm did produce many of the species which usually get grounded by such events- Lark Buntings in the grasslands, thrushes and warblers along riparian stretches, and swallows on every water body. Unfortunately the diversity of shorebirds was rather poor. A modified run of a similar route with a working bicycle and on a date which would balance more of the breeding birds plus migrants would likely garner a higher species count. Some major "misses" include Horned Lark, Bushtit, Townsend's Solitaire, Burrowing Owl, American Wigeon, Ruddy Duck, Golden Eagle, Ring-billed Gull, Chimney Swift, American Dipper, White-throated Swift, Lark Sparrow, etc, etc.
It was a fun and pleasingly exhausting day!
Thanks,
Christian Nunes
Longmont, CO