Challengers

Video below

It is now June, winter here in southeastern Australia, but the weather for the most part gentle, mild and sunny.

On 10 June the camera recorded some interesting behaviour worth posting here.

Odimbar the dark adult male sought to practise courtship with a green female bird. But through three of four three minute clips the two courtship desiring birds are subject to interference from green birds which I assume younger males. This is different from behaviour previously observed (in my limited bowerbird watching experience of less than three months) and I am led towards speculation that because we are heading for spring in less than three months when courtship will be serious there are younger birds challenging. I know of challenges among mature black bowerbirds. Does this movie reveal challenges from a bird or birds that would be pleased to take over and change plumage soon?

Well short of such speculation, you have to feel some sympathy for this couple trying to get time together.

There is mention in the literature from the Borgia group (see right column) of the way the aggressive sounds of the male satin bowerbird are very close to the courtship sounds, and that females can be unnerved by male performance. Well, here we see the multitasking male, holding a bottle top and a leaf in his mouth and trying to sing romance and 'buzz-off' at the same time, while dancing. Both male and female look at times frazzled by their situation... but wait for the fourth three minute clip.

I wrote in para three "practise courtship."  This does seem what is happening. It is not possible to know how many females may attend like this, but there seems to be 'practice' occurring, through this non-breeding season. Something collaborative, not just fly-by. The literature speaks of bowerbirds as practising polygyny, a precise term for that kind of polygamy in which the male has multiple partners, the female does not. Perhaps the one-partner conduct of females is clear with rings on legs of green birds; it's not otherwise easy to know. We have in earlier videos in these weeks seen a green bird in the bower practising being grown up for more than twenty minutes, we have also seen a female bird or birds in attendance off-season. We have also seen (but not filmed) green dance for green and black dance for black. There is nothing so simple as things less well studied.

I moved the camera again for better close-up view.