Date: 7/1/25 5:22 pm From: Marty <wolfmartinc...> Subject: [cobirds] South Fork BBS summary, Rio Grande
Greetings, CoBirders,
This past Fri (6/27) I completed the second of my 2 breeding bird surveys, which is in western Rio Grande County, south out of the town of South Fork (trending south & then eastward), going up to 11,600'.
Noticeable over most of the outer edges of the San Luis Valley (except for irrigated fields of course) en route to my BBS location--and apparently also over most of the Sangre de Cristo range and the San Juans--the region is quite dry now, after well below-average winter snows and far less of the nice spring rains the Front Range and much of the plains (except the northeast) have received.
Dirt roads in the Rio Grande Natl Forest where this BBS route is located were therefore drier & dustier than usual, and bird & bug numbers were significantly below average (despite there being plenty of beautiful wildflowers blooming, especially at higher elevations). Also, as noted in previous years' summaries, above 10,000' on this route the subalpine spruce forest has been significantly decimated by spruce beetle infestation, but the damage peaked 2-3 years ago.
This season I had 43 species on count day (with 6 additional sp. observed the previous day of scouting), which is average for this route--at least for the 13 years of my tenure. However, the count of total individual birds was the lowest it's been in my 13 years, at 307 (my average prior to this year being 404)-- in fact, this year's count of individuals is the lowest ever for this BBS, which started in 1994.
While I had greater-than-average numbers of 3 species (Green-winged Teal, Canada Jay, & Lincoln Sparrow), I had below-average numbers of 20 species! That includes zero Hairy Woodpecker, Olive-sided Flycatcher, and Cordilleran/Western Flycatcher; continued declines below-avg over the past several years of 5 other species (Broad-tailed Hummingbird [4], American Three-toed Woodpecker [1], Western Wood-pewee [4], MacGillivray Warbler [1], and Audubon Warbler [12]); lowest-ever numbers of Hermit Thrush (12) and Gray-headed Junco (4); and below-avg numbers of Com. Nighthawk, Warbling Vireo, Clark Nutcracker, Am. Crow, Mountain Chickadee, House Wren, Pine Siskin, White-crowned Sparrow, Green-tailed Towhee, and Orange-crowned Warbler). The remaining 20 or so species were at roughly average numbers, fortunately.
So you never know from year to year what all is impacting bird numbers or the time-frame of the impact, but clearly at least several factors may have been coming together to affect them now in this location-- widespread loss of living forest, repeated moderate-to-severe drought, with subsequent (temporary?) decrease in food availability... and who knows what for the migrants in their wintering ranges and journeys in-between. --& all exacerbated by ongoing climate changes.
Good birding, good actions for what sustains us all.
Marty Wolf Nw CO Spgs
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