canberrabirds

Birds hawking for insects (including Siver Gulls) [SEC=UNCLASSIFIED]

To: "'Baird, Ian'" <>, 'Susan Robertson' <>
Subject: Birds hawking for insects (including Siver Gulls) [SEC=UNCLASSIFIED]
From: Geoffrey Dabb <>
Date: Thu, 17 Nov 2016 00:05:39 +0000

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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