Anna's Hummingbird - Phys Ed or Sex Ed

[Joerg Rockenberger]

I've observed now multiple times a female jumping on the back of one of her young ones after she was done feeding it. In one case she actually pushed the little one from the branch it was sitting on. In the image posted here though it sure looks more like copulating... Anyone knows what this is about?

Thanks, JR

PS: And yes, a pity for the branch covering up the feet of the little one. Oh well...

[John Chardine]

In this particular case, as you describe it I haven't got a clue what might be happening.

[Jeff Wear]

Anyone knows what this is about? = San Francisco . Nice shot but no idea

[John Chardine]

Perhaps I can be a bit more helpful. It is a quite common observation to see all sorts of mounting/"pseudo-copulation" in birds. For example, males mount chicks and other males, females mount males. These examples probably have different proximate causes and are usually the result of simple behavioural rules of thumb going wrong. As described (female parent mounting own chick), it is hard to imagine what rule of thumb might be going wrong to begin with. However, here's some out of the box thoughts- maybe the "female parent" is in fact a young male previous sibling who is helping at the nest. This is unlikely because cooperative breeding is not known in hummingbirds. OK, so we know that male Anna's Hummingbirds typically have nothing to do with nesting other than copulation. There is one recorded observation of male Anna's feeding a chick so it's not unheard of. Males copulate with more than one female (and probably the reverse occurs too). What if this is again, a young male who fed the chick, which is not his own, and therefore broke a standard rule of thumb- only feed your own chicks-, then mounted the chick, which looks to him like a female. This latter behaviour would be entirely consistent with male Anna's rule of thumb- mount and attempt copulation with any other Anna's Hummingbird that looks like a female.

OK I'm about out of ideas.

Very nice image by the way.

[Joerg Rockenberger]

Perhaps I can be a bit more helpful. It is a quite common observation to see all sorts of mounting/"pseudo-copulation" in birds. For example, males mount chicks and other males, females mount males.

I did not know that. Thank you!

However, here's some out of the box thoughts- maybe the "female parent" is in fact a young male previous sibling who is helping at the nest. This is unlikely because cooperative breeding is not known in hummingbirds.

Perhaps one more piece of information: after feeding her two young the "female" returns most often to a nearby new nest and sits on it. The feeding and the nesting behavior are the main points for me to assess that it is a female and not an immature male. My ID skills are not good enough to make that distinction.

Very nice image by the way.

Thanks, JR