Hi Sonja,
I think they are most likely to be used to guide items of food (for eating)
and droplets of water or blood/haemolymph (for drinking) towards the base of
the open bill.
Grey Butcherbirds live in a range of environments, including semi-arid and
arid environments where free drinking water may be scarce. Some bird species
inhabiting drier environments rely largely on water in their food, dew
deposited on vegetation overnight and metabolic water production. It's
possible that excess blood and haemolymph from prey items are collected by
the bristles as the butcherbirds are eating their food and funnelled towards
the open bill. Similarly, bristles may collect due from vegetation and
funnel the water droplets towards the mouth. It is also possible that water
droplets collect on the bristles themselves overnight as a result of water
condensation from the bird's respired air and from other sources of dew.
Stephen Ambrose
Ryde NSW
-----Original Message-----
From:
On Behalf Of Sonja Ross
Sent: Tuesday, 6 July 2010 4:52 PM
To:
Subject: Grey Butcherbird
I am processing a photo of a Grey Butcherbird taken yesterday, and
because of the partial backlighting, bristles round the beak are
standing out, much more apparent than they would normally be. Some
are quite lon. Does anyone know what their purpose would be, or have
any theories about it?
Thanks,
Sonja
===============================
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
http://birding-aus.org
===============================
===============================
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
http://birding-aus.org
===============================
|
