Re: FW: [canberrabirds] Size of Great Crested Grebe

[Martin Butterfield <>]

Geoffrey: is that a variation on "Never Mind the Quality feel the Width"?  Perhaps something along the lines of "Never mind the dimensions see the weight"?

Martin Butterfield

http://franmart.blogspot.com.au/

On 23 April 2017 at 16:36, Geoffrey Dabb <> wrote:

Ah, but consider the weights.  According to HANZAB 383 Serendip coots averaged 510g (heaviest 725), while 5 fat NZ GCGs came in at 1075-1218   

 

From: Martin Butterfield [
Sent: Sunday, 23 April 2017 3:02 PM
To: COG List
Subject: [canberrabirds] Size of Great Crested Grebe

 

In an ebird posting about the Yerrabi Pond Great Crested Grebe a comment is made, supported by evidence in a photo, that the Grebe is slightly smaller than a nearby Eurasian Coot.  This surprised me more than somewhat as I had thought the Grebe to be much larger.

 

Consulting the overall measurements given in Pizzey and Knight this would seem to be the case.   The Grebe ranges from 48-61cm in overall length (averaging these gives 54cm) while the Coot is 35-38cm (37cm).  

 

On looking more closely at the checklist photo it seemed that it was the Coot's torso which seemed larger than that of the Grebe.  To check this out I measured the proportions of body parts of the two species as depicted in the Field Guide and scaled them up to the average lengths cited above.  The torso of the Grebe came out to 25.8cm while the Coot came in at 23.1cm (roughly 10% smaller).  

 

If however one takes the smallest length quoted for the Grebe and the longest length given for the Coot one gets 22.9cm for the torso of the  Grebe and 23 .8 (~5% larger) for the Coot.  

 

So it would appear that the Grebe is a small specimen while the Coot has clearly propered on whatever its been finding to eat in the Pond!

 

Martin Butterfield

http://franmart.blogspot.com.au/