Tweeters,

At 9 pm 15 May Ellen Quiring and myself observed the male Costa's Hummingbird near Richmond Beach in the North Seattle area. It has not been at all regular at the feeder during the day since ~ the first week of May, but is apparently coming in at very last light. After three visits totalling ~ 2 hours of observation, here's my interpretation of what's going on here: this particular feeder seems to be dominated by a male Rufous Hummingbird, with occasional visits by a male Anna's, perhaps making stealing bouts by the tiny Costa's too tiresome. However, I sense this Costa's is maintaining "his pulse" on all food sources in the neighborhood (his "trapline"), but either due to his subordinate status (smaller, less aggressive than either of the other two species in the area), perhaps to lower yields at this feeder, or, for some other
reason (s), he is not regularly visiting this food source.

Watching hummingbirds is such great fun and to see these three species all in the span of 15 minutes was truly exciting. It prompted me to reread the memorable chapter "Territories or Traplines? Hummingbird Foraging Strategies" in in Steven Hilty's great primer on Neotropical birds: "Birds of Tropical America: a watcher's introduction to behavior, breeding and diversity" (1994. Chapters Publishing. Shelburne VT). Hilty outlines the strategies many species of hummingbirds have developed to cope with an ever-changing food resource - nectar-bearing flowers - in which one (the "trapline") finds the hummingbird constantly on the move from flower source to flower source, even over hundreds of yards, in order to keep their voracious appetites satisfied. Another strategy is the territorialist (Rufous is a good example of this), where the hummer aggressively defends a favored flower patch.

By the way, seeing the Costas Hummingbird was an added treat on my Birthday!

P.S. I'm not at all sure whether directions to this feeder are supposed to be public info...sorry. The homeowner, however, seemed to be very open about visitors. Maybe someone in Seattle can find out and allow others to view this first-time Washington bird, a waif from the desert southwest.

Andy Stepniewski
Wapato WA
steppie at nwinfo.net