Interesting information. Will be waiting to see what our resident authorities have to say about this.

Fascinating idea, but it appears to be 95% malarkey. If it were true, wouldn't you be seeing only one bird, period? The real reason that you see mostly females in your yard is that breeding males are highly territorial while females are not. Territorial male Ruby-throateds exclude other males from their little patch of earth and sky, and females visit them on their territories when they're in need of "services" (though occasionally males will visit and court females at nests under construction). Females have more pressing responsibilities than territorial defense during the breeding season, though they often behave aggressively with both males and other females around feeders and flowers and may even chase other females away from their nest sites (maybe just to keep them from stealing nest material).

As for western species being more "cooperative" than Ruby-throateds - HA! The diversity of species out here complicates the behavioral picture, but it doesn't follow that there's some sort of "peaceable kingdom" among western hummingbirds. On their wintering grounds, Ruby-throated have to compete with lots of other hummingbird species, and they have trouble holding feeding territories against any species except those smaller than they are; at wintering sites in the U.S., Rufous routinely dominate Ruby-throateds. If anything is responsible for the numbers of birds at feeding stations such as Frank's, it's the larger populations of breeding and migrating birds as well as species diversity that we have out here due to our greater diversity of hummingbird habitats.

Thank you for the accurate story on this subject. 'Malarkey' was one of the kindest words that popped into my mind as I listened to him. I've heard him say many incorrect things in previous visits, and strongly suspect he's a well-intentioned mountain of misinformation.

After decades of watching hummingbirds I feel I'm far from an authority. A few things I have noticed. At the dozens of nests I've observed over the years I have never seen a male nearby. Most years my yard is controlled by a male, but in years when a female has charge, no males are present after migration and before July. This year was fairly typical. Various females would visit from 3 of the 4 quarters, feed for a short time, enjoy the male's dance, and then head back where they came from. It is my guess that the females are mainly coming to visit the male. They do very little feeding and then head off in directions where Japanese Honeysuckle infestations are the thickest. Like most other observers who have multiple birds, the whole situation changes around the first of July. Around here the J. Honeysuckle bloom slows down and the gardens become more attractive. I have no idea how many hummers are actually using the yard and the feeder as of this week, probably only several because I'm not seeing any confrontations.

I asked last year about only seeing females and nobody seemed to know. In spring migration I only see males for a few days, and after that it's all females. So I must live in the female territories. This year being what it is (BAD) I had a male come every night at dusk for a couple of weeks, and some far and few between females.