Period of July 20 - July 26, 2012
Numbers of birds processed are up by nearly 16% this year. This is probably due to a correlation between low snowpack levels and high avian productivity. Yosemite got about 30% of its average snowpack this year which means that bird populations should be having more offspring. We were definitely seeing this in the nets this period where 3 out of every 4 birds processed had hatched this year.
Interesting birds seen this period included the Black-throated Gray Warbler, Calliope Hummingbird, Green-tailed Towhee, Lesser Goldfinch, Stellar's Jay, and Wilson's Warbler. These birds are rarely found in the researchers' nets. The Calliope Hummingbird, at 3.25 inches in length, is easily the smallest bird that visits Yosemite, beating the Rufous Hummingbird by half an inch. Like many wildflower enthusiasts, the Calliope follows the shift in blooming wildflowers throughout the season. It arrives on the lower slopes in April or May and slowly moves upslope until, by July or August, it is ready to make the journey back south along the highest slopes.
List of 35 species recorded from July 20-26:
HUMMINGBIRDS
Anna's Hummingbird (Calypte anna)
Calliope Hummingbird (Stellula calliope)
Rufous Hummingbird (Selasphorus rufus)
WOODPECKERS
Red-breasted Sapsucker (Sphyrapicus ruber)
Williamson's Sapsucker (Sphyrapicus thyroideus)
Northern Flicker (Intergrade and Red-shafted) (Colaptes auratus)
FLYCATCHERS
Dusky Flycatcher (Empidonax oberholseri)
Pacific-slope Flycatcher (Empidonax difficilis)
Western Wood-pewee (Contopus sordidulus)
VIREOS
Warbling Vireo (Vireo gilvus)
JAYS
Steller's Jay (Cyanocitta stelleri)
WRENS
House Wren (Troglodytes aedon)
Pacific Wren (Troglodytes pacificus)
WARBLERS
Black-throated Gray Warbler (Dendroica nigrescens)
Hermit Warbler (Dendroica occidentalis)
MacGillivray's Warbler (Oporornis tolmiei)
Nashville Warbler (Vermivora ruficapilla)
Orange-crowned Warbler (Vermivora celata)
Wilson's Warbler (Wilsonia pusilla)
Yellow-rumped Warbler (Audubon's) (Dendroica coronate)
SPARROWS
Dark-eyed Junco (Oregon) (Junco hyemalis)
Chipping Sparrow (Spizella passerine)
Lincoln's Sparrow (Melospiza lincolnii)
Song Sparrow (Melospiza melodia)
TOWHEES
Green-tailed Towhee (Pipilo chlorurus)
FINCHES
Lesser Goldfinch (Carduelis psaltria)
Pine Siskin (Carduelis pinus)
Purple Finch (Carpodacus purpureus)
OTHER BIRDS
Black-headed Grosbeak (Pheucticus melanocephalus)
Bushtit (Psaltriparus minimus)
Red-breasted Nuthatch (Sitta Canadensis)
Brown Creeper (Certhia Americana)
Golden-crowned Kinglet (Regulus satrapa)
Lazuli Bunting (Passerina amoena)
Western Tanager (Piranga ludoviciana)
Table 1. Comparison of Birds Processed during Period 9
(Last Week of July), 2011 to 2012
| Station | 2011 | 2012 | % change |
| Big Meadow |
74 | 36 | -51.3 |
| Hodgdon (upper) |
38 | 71 | +86.8 |
| Hodgdon (lower) |
38 | 63 | +65.8 |
| Crane Flat |
87 | 74 | -14.9 |
| Gin Flat |
36 | 33 | -8.3 |
| White Wolf |
16 | 58 | +262.5 |
| Total Recorded |
289 | 335 | +15.9 |