ODIMBAR (One Day I Might Be A Raptor) was not here on 5 April 2017, but had set up his court by 14 April. From behaviour we have considered that he is newly adult-fledged, but he could be an older bird who has shifted his court. It is autumn and the courting that dominates reporting on bowerbirds is not due till spring.

As we begin this blog on 16 April 2017, we already have our hearts in our mouths, concerned that this new family member outside our suburban bedroom window will survive the competition and that his court may thrive. His day is busy: hunting, building, learning, asserting, defending, charming, singing, raucous caucusing and dancing.

And the evidence before us, of daily life, is much more complex than what one usually reads or views on Youtube, of isolated males building bowers in spring to try to entice picky females with whom their relations are fleeting. It's not like that at all here.

Thursday, April 20, 2017

Day 7

Day 6 was overcast, uncertain weather. The were bird calls all round the house. But I saw no action at the bower. This perhaps because I stayed in the dark dealing with migraine and meniere's attack. And writing, elsewhere, about Korea, in some fury.

But I was also reviewing whether this curiosity of a bower with a cast of many in autumn might be an anomaly caused by the weather. It has been for the most part, balmy weather for the last week or so, overnight around 14c, daytime 23-25c. This in contrast to the end of February and early March which was dark and squally, if not as cool as now. So dark our hens stopped laying. (I have another explanation for that: we moved their accommodation.) But it is important to keep that explanation open.

But not today! I was entirely caught up, with two others, working in the garden, so no movie. But there was great activity around the bower. So questions remain open:

  • Is the weather falsely suggesting it is spring... in which case what follows?
  • Is Odimbar going to maintain his performance for months... is there any normality to such?
  • Who is the Yuthiwim? I do not want to anthropomorphise or relate to any human culture, but there is a bird in the plot with a special relationship. I believe that after this week I can say it is one bird not a string of different birds. I believe, from plumage and behaviour, that this bird is not part of the juvenile pack. Is Odimbar her child? Is Odimbar older than we thought? Is this a bird from another spring time? Is there other observed history of such a female role? 
  • Will we keep seeing The Pretender perform? Is this a prelude to challenge? Or will he be driven off to find his own territory? And... why is he doing this? What prompts a bowerbird to perform? Does... speculative question... the sight of the bower and the opportunity to perform prompt a bird of a certain disposition and a certain stage of development to get in there... and does the performance lead on to further biological change and development of adult male feathering?
  • We know that the adult male satin bowerbird not only has to maintain his bower but also must patrol and secure his whole territory. Will there be challenge from any other mature bowerbird? In what form? 
  • A person left a blue bottle top on my letterbox, seen early today. Later it was gone, perhaps to Odimbar's bower, perhaps elsewhere (to the postman?). Certainly early this morning I saw a green bird steal a blue bottletop from Odimbar's collection. For whose bower, where?
I have just read Graeme Chapman's observations against which I need to check my own,
In suitable habitat bowers may average five per sq. km. and be spaced roughly 300 metres apart, so each male is well within earshot of his neighbours. In each territory, there is usually a number of green birds, either females (black bills) or subordinate males (pale bills) that may try to establish rudimentary bowers; these subordinate males don't acquire blue adult plumage until their fifth or sixth year. The main bower in a territory is maintained by a single blue male. That is where he courts and finally mates with his females (he mates with several) and it is the centrepiece of the territory. There is fierce competition at these bowers - neighbouring males will attempt to destroy the bower and pinch the sticks or ornaments, taking them to their own bowers and young males also come to try to display and steal things as well. Usually a new bower is constructed each year, close to the previous one - the site is traditional - it may be used by a succession of different owners. Decorations are mainly blue, violet, purple or greenish yellow. The blue tail feathers of Crimson Rosellas are a favourite in the wild, but near habitation all sorts of plastic objects are collected. At one stage near Sydney birds were removing the blue plastic rings off the top of milk bottles and getting their heads stuck in the ring, so the makers kindly changed the colour of the ring - end of problem.

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