canberrabirds

Thoughts on the 2 local ravens (2)

To: "" <>
Subject: Thoughts on the 2 local ravens (2)
From: Philip Veerman <>
Date: Sun, 11 Jun 2017 07:05:12 +0000

All useful ideas. However about the quote:

 

“Little Raven … [has] well-developed hackles (contra popular belief) that can be raised (mainly when calling) to form a large beard …”)

 

Even if so, the ‘beard” is bigger in the Aust Raven. For any of these birds, I suggest the better word would be “lowered”, rather than “raised”.

 

 

 

From: Geoffrey Dabb [
Sent: Sunday, 11 June, 2017 11:43 AM
To:
Subject: [canberrabirds] Thoughts on the 2 local ravens (2)

 

Steve is correct in treating the bare underchin patch as diagnostic of the A Raven if it can be seen. By comparison many other suggested differences are little more than possibly useful pointers. I should mention that HANZAB devotes much space to listing and discussing points for ID-ing Australian corvids, from (1) MAIN CALLS to (9) FLOCKS AND BREEDING DISPERSION.   (On one point: “Little Raven … [has] well-developed hackles (contra popular belief) that can be raised (mainly when calling) to form a large beard …”)

 

Back to the Australian Bird Guide.  This says for the Little Raven:

 

<<  Throat hackles short and bifurcate, but form a short, spiky ‘beard’ when calling.  Head profile distinctive: rounded crown with steep forehead and shortish, pointed bill ( ~  equals head length) >>

 

HANZAB says in the ‘Field Identification’ section:   <<  Medium sized, stocky raven with:   rather short, stubby bill, with decurved upper mandible and slight hook at tip, rounded forehead and crown and short stout neck >>

 

However the ABG illustration does not bring out the suggested difference from Little and A  Ravs, with both illustrations showing almost identical ‘rounded crowns’.

 

By contrast the Frank Knight illustrations in Pizzey 7th ed are helpful in showing the difference but (the dilemma of any field guide) unhelpful in suggesting it will be so obvious:

 

 

Unfortunately ‘steepness of forehead’ is likely to depend on the angle of view, posture of the bird, and whether feathers are flat or raised. In the below, first 2 are A Ravs, third is a Little Raven:

 

 

 

Next:  the problem of size.

 

 

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