Thoughts on the 2 local ravens (3)

[David Rees <>]

The point you make about lack of 'bird-length' is in my view one of the deficiencies of the new CSIRO field guide.  While the wing, beak etc. measurements are absolute data, however, they are of little use on their own to an 'observer'. Most customers of this field guide will be observers.  Case of 'purity' over 'practicality' here.

The new book seems to me to be a close copy of the format used by Svensson et al (1999) in their European field guide, first published in Sweden, but probably better known to readers in its English language edition published by Collins as the 'Bird Guide ......"  It seems a pity to me that CSIRO Publishing did not follow the size format used for that book, which is far more compact and field friendly.  See what I mean in photo enclosed

That said, the artwork in the new field guide is magnificent, and probably the best out there from anywhere and the artists and authors should be congratulated for that.

David

On Sun, Jun 11, 2017 at 3:16 PM, Geoffrey Dabb <> wrote:

Bird length is not a straightforward matter.  Most field guides give it as offering some kind of help in appreciating size.  The Australian Bird Guide departs from that practice, giving instead wing, bill length and weight (these generally taken from HANZAB). Among the reasons for not giving length: ‘the measurement [is] typically taken from dead specimens  stretched into positions that are never assumed in life.  Trying to reconcile the total lengths presented in books with those observed in the field can therefore be confusing.’  (ABG does offer a scale on the illustration pages.)  HANZAB does not give tabulated lengths in the Plumages section but does provide length in the field identification section ‘in gross terms, as a guide to the size of the bird’.  

 

Bearing in mind that warning, the following given ‘lengths’ (cms) might be noted:

 

Aust Raven:  HANZAB 46-53;  Pizzey 48-52

Little Raven:  HANZAB 48-52;  Pizzey  48-50

 

From weights and other size info in HANZAB it is clear that males are larger than females so a female A Rav might be no bigger than (or even smaller than) an individual Little Raven. 

 

Relative sizes might only be an issue if you see both species together – and particularly if you are counting species.  The below is a selection of snaps from Trucking Yard Lane last week when a single A Rav was squabbling with 4-5 Little Ravens at the remains of a deceased duck.  You can correct my tentative labelling, if you like.

 

 

 

 

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