Crimson Rosella - a measure of breeding success?

["Harvey Perkins" <>]

More interesting comments - I wasn't aware of the male female differential in plumage change timing.

 

Re Michael's comment about seeing fewer young Crimson Rosellas this season, I haven't noticed the same thing with the rosellas around my place in Kambah. While I haven't made counts on adult vs yound birds I certainly haven't felt that this year is any different to previous years in terms of proportions of adult and young birds. I wonder if there could be a difference in breeding success between suburban birds vs Canberra Nature Park birds (or do your birds move between suburbs and CNP Michael?)

 

Harvey

 

On 31/01/07, Chris Davey <> wrote:

Interesting observations Michael.  The lesson here is that we should all spend much more time noting the proportions of the different plumages.  I was talking to Dick Shodde and he agreed with my observations that one often sees a pair of Crimson rosella of which one is in juvenile plumage.  This is because female take longer to acquire the full adult plumage and not because the older male is only interested in a younger female or because there is a disproportionate loss of females from the population.

 

Chris

 

-----Original Message-----
From: Michael & Janette Lenz [mailto: m("homemail.com.au","lenzmj");" target="_blank">]
Sent: Tuesday, 30 January 2007 9:58 PM
To: chat line
Subject: [canberrabirds] Crimson Rosella - a measure of breeding success?

 

As part of a small project I have I count sometimes at a point on Mt Majura birds passing by in the afternoon on their way to a roost, this includes Crimson Rosellas. This afternoon (30 Jan.) out of a total of 102 birds only 7 were young, i.e. about 7% of the birds. Although in the past I have not separated birds by age class, just from general impressions, the count tonight would indicate very poor breeding success. Most birds passed as pairs or groups of adults only, very few family parties were seen.

 

This is matched by  day observations in the suburb of Ainslie, on Mt Ainslie and a few other areas I visit: there are some young around, but far fewer than in a "normal" year.

 

Clearly the drought is biting and even species we may not consider to be too much affected, definitely are.

 

Michael Lenz