Field guides strike again - rosella nesting

["Philip Veerman" <>]

The comment by Chris provides a consistent context for me to describe what happened with the next box (from the Myna project) I can see from my kitchen and study window in this current spring & summer. Apart from a week away in January I am pretty much home all day every day, so I think this is a full story. Last year (2010-2011) it attracted only Mynas. This year it had a pair of Eastern Rosellas attending it from GBS weeks 36 to 43. The male would sit on the box and chatter and tail wag whilst the female would go in. In week 43 I observed one dispute lasting just a minute or two of this pair of Eastern Rosellas with a pair of Crimson Rosellas at the site and have never seen the Eastern Rosellas return. The pair of Crimson Rosellas were an adult plumaged male with a female that is still in mostly green plumage. They attended from weeks 43 to 48. I assumed just one pair and whilst the female spent a lot of time in the box, I could usually see her head at the entrance hole which shows she could not have been sitting in the box, just clinging to the inside wall. At one time I saw a second pair of Crimson Rosellas also one adult plumaged one and one still in mostly green plumage have a fight over the box. Such that then I didn't know who was the "rightful owner" as I couldn't see any difference between these two pairs. In week 48 we had a heavy rainstorm and they abandoned it and nothing has used it since.

 

Philip

 

-----Original Message-----
From: Chris Davey [
Sent: Friday, 27 January 2012 1:09 PM
To: 'Geoffrey Dabb';
Subject: RE: [canberrabirds] Field guides strike again

Thanks for this Geoffrey.  I cannot help but wonder if it is a general  feature that where males and females wear similar adult plumage, females take longer to acquire it than do males.  Appears to be the case with Magpies and I wonder about Crimson Rosellas where so often an adult plumaged male is paired with a female that has not yet acquired the full adult plumage.  Anyone with aviary experience care to comment?

 

Chris

 

From: Geoffrey Dabb [
Sent: Friday, 27 January 2012 11:20 AM
To:
Subject: [canberrabirds] Field guides strike again

 

Well, that was Australia Day.  To the long-time observer it is getting excruciatingly more Australian each year, in fact you’d wonder just how Australian it can get.   To the bird observer, the afternoon was enlivened by the commentary at the Australian open tennis about the ‘starlings’ swooping so low over the court that they were in danger from the swishing racquets.   Chasing moths, we were told.  Oh well, no worse on bird ID than the golf commentators.

 

With friends from Merimbula in town for the bridge competition we were able to have the White-headed Pigeon discussion again.  This begins with the assertion that the females can be told by their mottled greyish breasts.  This rumour can be traced to the field guides which, again, are guilty of excusable oversimplification.  The HANZAB illustration supports the theory.  However according to the HANZAB text females are just slower to move from the juvenile plumage, older females being indistinguishable from adult males. Accordingly, in the below, the left bird is probably a young female, the middle bird is only probably a male but could be an old female, and the right hand bird is a non-old female.