Sunday, August 16, 2015

The Black Swifts of Box Canyon Falls

Nesting Black Swifts tend to be difficult to observe as they typically occupy nest sites behind inaccessible mountain waterfalls. An exception is the well established nesting site at Box Canyon Falls in Ouray, Colorado where I visited recently.

Black Swift

Box Canyon Falls is itself a natural wonder; over time the rushing waters of Canyon Creek have eroded a deep tunnel or "box canyon" through a layer of fault-weakened limestone. The resulting waterfalls, surrounded by canyon walls on all sides is ideal for nesting Black Swifts. The site is easily accessible by a short trail and the canyon walls can be directly accessed via a metal scaffold and suspension bridge.

The State of Colorado is the stronghold of the breeding range of the North American race of Black Swift, and Colorado has been extensively censused for the breeding locations of these birds. Information about the life history as well as details about the efforts to record the nesting sites of these birds has been documented here. North American Black Swifts are migratory, however there is a separate Caribbean race of Black Swift that is non-migratory. It is noteworthy that Black Swift was the final North American migratory bird to have its wintering grounds confirmed; a discovery that was not made until 2010.*

Cordilleran Flycatcher

Other birds in the vicinity included Broad-tailed Hummingbird, Cordilleran Flycatcher, American Dipper, Western Tanager, Black-headed Grosbeak and Cassin's Finch.

"Audubon's" Yellow-rumped Warbler

As a side note, Ouray is a mountain town that attracts various tourists and adventure seekers. The most prominent activity in the summertime is off-roading and there were abundant jeep rental agencies in the area.

Ouray, CO

*Beason, J.P., C. Gunn, K.M. Potter, R.A. Sparks, and J.W. Fox. 2012. The Northern Black Swift: Migration Path and Wintering Area Revealed. Wilson Journal of Ornithology 124:1-8.


Laura Purdy said...

Nice pics, Rob. I forgot to ask you about your trip to Colorado. The pic of the black swift at its nest is beautiful.

Robert Maciver said...

Thanks, Laura. I had a good trip.