birding-aus

Re: Birds' feet

To: <>, <>
Subject: Re: Birds' feet
From: Dean Portelli <>
Date: Thu, 29 May 2008 01:14:21 +1000

Hi Sonja,

 The term talon is usually restricted to birds that use their feet to subdue or 
kill large prey or are relatives of species that do and have retained the same 
foot morphology (typically owls and 'diurnal' birds of prey). For other birds 
these are usually referred to as claws. The damage that talons can produce 
comes mainly from the strong tendons controlling movement of the toes. Anyone 
who has handled large honeyeaters can attest to the sharpness of their claws, 
but they don't have the force to break the skin. Other birds have sharp claws 
used for gripping or climbing, for e.g. treecreepers.
 Anatomically a claw consists of a bone covered in a keratin sheath. There is a 
blood supply internally to nourish the keratin as it grows (like fingernails 
the keratin grows outwards from the body, it is dead tissue at maturity). This 
is why trimming bird's claws can result in considerable bleeding if cut 
anterior to the end of the 'quick'. The sheath continually wears and is 
replenished by new inner layers. This is also true of the keratinous sheath 
covering the bill (termed the rhamphotheca).
 With regards to the Gang-gang with the deformed claw. It should be perfectly 
fine. It is not unusual to see wild birds lacking a claw or two. For example, 
several newly caught babblers (i.e. not previously captured) that I work on 
have had a missing claw, either broken at the base or absent and have a stubby 
toe. No doubt this is painful when the injury occurs but birds are able to 
adapt to the slight disability, including wild parrots which I have also seen 
several with a missing a claw apparently with no ill-effect. So the gang-gang 
should be fine.

Cheers, Dean




Date:
Wed, 28 May 2008 20:15:00 +1000




I am processing some images of Gang-gang Cockatoos taken today, and while 
checking sharpness, have noticed that one of the talons (is that correct, by 
the way as all the books seem to just cover feathers) is broken. It seems to 
taper in from the edges to form a hole. It made me wonder if this would 
adversely affect the bird - altering it's grip for example or causing pain like 
dental caries, or just be like a broken finger nail, and are they hollow, like 
cow horns? Can anyone enlighten me please? Sonja Ross

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