[Tweeters] Startling (to me) Anna's hummingbird behavior - male attacking juvenile

Tucker, Trileigh TRI at seattleu.edu
Fri Apr 14 13:59:04 PDT 2017

Hello Tweets,

I’ve been observing an Anna’s Hummingbird nest in West Seattle. In the past couple of days, the two juveniles have fledged, one perhaps a day before the other. As of yesterday afternoon, the mother was still feeding them.

One surprising behavior (not the one of the subject line) was seeing her feed one juvenile, then fly to the nest and poke around in it, as if there were a baby still there when it was clear there wasn’t.

But what I found startling was when a male adult Anna’s flew over to one of the juveniles (I believe the first-fledged, since it was a better flier than the other) on a nearby branch, and started attacking it ferociously. At least, that’s what it looked like to me. There is a photo sequence here<https://www.flickr.com/photos/trileigh/albums/72157679288941754>, 6 (selected ones) taken over the course of about 12 seconds.

The mother didn’t enter the picture as far as I could see. At first the baby didn’t seem to know what to do, then toward the end seems to open its beak in protest. It looks like the male is either/both poking at the juvenile’s breast or trying to pull out feathers, then the male almost seems to land on the baby’s back. It was interesting to me that he basically bends over backward in this apparent attack against an unreactive victim.

The male finally flew off and the baby was unharassed after that for at least the half-hour I stayed at the scene.

I did some online searching and didn’t find reports of such behavior, although maybe I didn’t find the right search terms. So I wonder whether the male was unperturbed while the babies were in the nest, but when they fledged suddenly decided they were competition invading his territory? Or was he just investigating? Is there any evidence about whether Anna’s fathers recognize their offspring? It would seem maladaptive to attack one’s own.

Thanks for any interpretations or similar observations you may have.

Good birding to all,

~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Trileigh Tucker
Pelly Valley, West Seattle
Natural Presence Arts website<https://naturalpresencearts.com/>

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