According to the annual cycles illustrated in their respective BNA species accounts (The Birds of North America, Cornell Lab of Ornithology, Ithaca, NY), Black-chins and Broad-tails are essentially half-way through their fall migration periods, whereas Rufous and Calliope are roughly 2/3 of the way through theirs. But these are generalized migration periods for the purpose of graphic illustration, i.e., not precisely the same throughout their ranges (north/south in particular), and our Black-chin numbers are already less than half of what they were a couple weeks ago. The graphic for Calliope shows “??” for October, whereas every year in W Colorado we had Calliope linger to about the 2nd week of October, and one year an adult male remained into November. Broad-tails were nearly always first to depart, and Black chins were last (one year a hatch year bird almost made it to our Grand Junction CBC). Lots of variables are at play regarding migration, oui?
Heidi, our eyes are peeled for a first-of-season Anna’s, as in “ Here, hummer-hummer-hummer!!”
Speaking of Anna’s, their annual cycle in coastal California includes “??” for both migration and molt ( Clark, C. J. and S. M. Russell (2012). Anna’s Hummingbird ( Calypte anna ), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.226 ). FWIW, I’m attaching this below, not knowing if it will survive cyberspace and be legible………
Larry
Enlarge Figure 5. Annual cycle of Anna’s Hummingbird in coastal California.
Figure 5. Annual cycle of breeding, migration, and molt in a coastal California population of Anna’s Hummingbirds. During migration, birds move into mountains and southeastward across deserts; they depend on finding ephemeral food sources and may stay weeks in a place if food persists. Thick lines show peak activity, thin lines off-peak.
