Correction! Learned to hawk from each other, that is!
Ian Baird
From: Geoffrey Dabb [
Sent: Thursday, 17 November 2016 11:06 AM
To: Baird, Ian; 'Susan Robertson'
Cc:
Subject: RE: [canberrabirds] Birds hawking for insects (including Siver Gulls) [SEC=UNCLASSIFIED]
Crikey, Ian! On a quick first reading I took it that several bird species learned the technique FROM the CBN article. Anything is possible these days …
From: Baird, Ian
Sent: Thursday, 17 November 2016 10:13 AM
To: Susan Robertson
Cc:
Subject: [canberrabirds] Birds hawking for insects (including Siver Gulls) [SEC=UNCLASSIFIED]
Hi Susan,
Henry Nix drew attention to birds hawking for insects generally in his Canberra Bird Notes (CBN) note: ‘Vertical hawking by both native and introduced birds in Canberra’ in CBN 4:5 p 24 in the January issue of
1979. He suggests, based on his observations, that several different birds species may have learned the technique in that article.
The note I referred to about Silver Gulls hawking was by myself and Henry in the following CBN issue 4:6 pp.9-12 published in April of the same year, see the direct link to that issue on COG website below:
http://canberrabirds.org.au/wp-content/uploads/2012/06/CBN/cbnvol4no6.pdf
I think I misdescribed the prey at least some gulls were catching in the 1979 article above. Upon reflection. I now think the beetle prey was probably of the Porrostoma genus I mentioned in my recent email.
In that beetle species the elytra (wing cases) themselves are coloured orange, not the body.
Ian Baird | Senior Policy Officer
Phone: +61 2 6207 2336
Nature Conservation Policy
| Environment, Planning and Sustainable Development Directorate |
ACT Government
Level 1 North, Dame Pattie Menzies House, 16 Challis Street DICKSON | GPO Box 158 CANBERRA ACT 2601 |
www.environment.act.gov.au
From: Susan Robertson
Sent: Thursday, 17 November 2016 7:15 AM
To:
Subject: [canberrabirds] More on gulls
Thinking about what the gulls were hawking for yesterday, I think that it could have been midges newly hatched from larvae at the bottom of Lake BG. They were TINY as I couldn’t see them with or without binoculars. The gulls were hawking
from nearly ground level up to 100 metres. As I saw several gulls flying with their beaks open, perhaps they were scooping the midges out of the air. That’s my best guess.
Susan Robertson
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