White-throated Swifts at the Lyons hogback at Deer Creek. JeffCo

[David Suddjian]

Several weeks ago I reported on White-throated Swifts at a roost on a cliff on the Lyons Formation hogback where it is dissected by Deer Creek. A recent photo of the cliff in question is below.

Swifts have been continually active in the vicinity of the cliff each time I have visited the area late in the day, but have not been reliable at other times. I have not viewed the cliff in the late afternoon for a couple of weeks, but I did on Oct 5, 6 and 7. There were still good numbers of swifts present each date. It is hard for me to gauge the total number that might be around over an extended period of the afternoon, and they both enter and exit the roost. But I report my estimates of swifts in view "at one time" (during one complete scan) -- Oct 5: 90; Oct 6: 80; Oct 7: 40. The lower count on Oct 7 may be due to a later timing of my visit. 

On Oct 5 a bunch of swifts shot into the favored roost crack as early as 4:06 pm, but they may well have come back out. On Oct 6 there were high winds blasting from the west that I thought were up to 50 mph, and steadily 30-40 mph, and these aero-masters went about their racing around with no apparent loss of control or of verve in maneuvering at the cliff face. When they flew downwind they were moving incredibly fast. Tonight they were actively entering and exiting two cracks at 6:05 pm. I heard vocalizations a little bit during each visit, but only a little bit. Even tonight, as a Red-tailed Hawk soared across the cliff face less than 2 feet from the roost crack, the swift cloud just dispersed in silence for a moment and let the hawk glide through.  

It will be interesting to visit again after this coming cold front.

David Suddjian

Ken Caryl Valley

Littleton, CO

​Lyons Formation hogback at Deer Creek, near W. Buckhorn Drive

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