Winter Say's Phoebes & Multi-story Buildings (Arapahoe)

[Jared Del Rosso]

Not all Say's Phoebes that visit in the winter take to multi-story buildings, but three of my last four have. In February 2016, I had a Say's Phoebe high up on an apartment complex adjacent to Denver Botanic Gardens. In February 2017, I had one on top of Sturm Hall at the University of Denver; I watched it from a window on the building's fourth floor.  Today (1/13), I watched, from a second floor library window, a Say's Phoebe flycatching off of light fixtures on the 3rd through 5th floors of an apartment building in Streets of Southglenn (Centennial in Arapahoe County). 

I'm not the only one. On January 1, 2018, a large group (CBC'ers, I presume) had a Say's Phoebe on top of a building at Denver Botanic Gardens. (Checklist with photo here.) A December 2017 Say's at City Park was on top of the science museum. (Checklist with photo here.) And soon after I reported the DU phoebe, Joe Roller soon emailed me to share a very similar, winter report. Browsing through eBird photos of the bird in Colorado, with the date filter set to Dec - Feb, reveals many, though certainly not most, of reported phoebes are on human structures and often large ones at that.

Are these, presumably warm, buildings passable habitats for flying insects and, if so, should we convert more open spaces to multi-story apartments (kidding on that one!)? And are those insects likely mainly house flies, which is all I've seen around my home over the past month?

- Jared Del Rosso

Centennial, CO