David and Tweeters,

About two months ago I asked if it is typical for a male Anna's
Hummingbird to completely take over a feeder to the exclusion of all
females, and the general consensus was YES. Since then, my male Anna's
has somewhat relinquished his grip on the feeder outside my kitchen,
and I often see females/juveniles getting in to feed. Perhaps the male
dominates when he is present, but he sometimes goes somewhere else and
then the others can visit that same feeder. I also have another feeder
on the other side of the house, and there is a juvenile female (I
think) who frequently visits that one.

Barry Ulman


On Jan 6, 2011, at 1:01 PM, David Hutchinson wrote:

> Hummingbirds, in general, are opportunists, certainly exemplified by
> our local ANHU. There are really two questions here: 1) Does male
> competition limit female survivorship based on feeder use? I know of
> no evidence that this is true, while humans seem to be adding feeders
> along with the expanding hummer population?. The sex ratio in ANHU is
> skewed in favour of males in any case. Traditionally West Coast
> hummingbird females are heavier than males, which may enhance their
> competitive abilities. However in S.Calif males are heavier than
> females, about which I won't speculate.
> 2)Is female Annas' ability to raise young hampered by male competition
> at feeders? Based on my feeder study in Magnolia/Discovery Park the
> answer is clearly no.Females appeared to drastically cut back their
> use of feeders once they were incubating The hatching of their young
> seems to correlate closely with the blooming of local native woodland
> species, such as Red Flowering Currant, followed by Salmonberry and
> many other native and introduced ornamentals. With all the mild
> temperatures we have had recently, the first bloom of Indian Plum in
> our forests and green belts cannot be far away.
> Similarly Rufous Hummingbird nesting in our latitude is timed around
> the blooming of Salmonberry, irrespective of what garden plants are
> available. Another question of interest is: What effect does
> inter-specific competition between Annas and Rufous have. While
> perhaps smaller Rufous tends to dominate Annas at feeders if only
> through sheer numbers at feeders. But Annas fledge well before Rufous
> and could be second-nesting while Rufous fledge. There is evidence
> that Annas can double clutch here. I don't know what the story is for
> Rufous however.
>
> --
> David Hutchinson, Owner
> Flora & Fauna: Nature Books
> Discovery Gardens: Native Plants
> 3212 W.Government Way
> Seattle,WA.98199
> http://www.ffbooks.net/
> 206-623-4727
>
>
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