My son and I have recently been watching a
blackbird nest right outside his bedroom window in a feijoa tree. Mum blackbird
came in and fed a nestling; the nestling then quickly turned around, and
presented mum with a faecal sac, which she promptly ate. Elliott thought it was
hysterical.
For those of you that think it’s
weird that I allow blackbirds to breed, I figured the education benefits for my
three year old outweighed anything else.
Interestingly, we were all away for five
days and during that time the two young (quite large, but with down and pin
feathers only) disappeared. So did the 20 day old unhatched egg. I would have
enjoyed watching the currawong eating that one!
Anthony
-----Original Message-----
From: David Rosalky
[
Sent: Sunday, 2 December 2007 8:55
PM
To:
Subject: Re: [canberrabirds] RE:
Would swallow?
Nice shots, Stuart. I presume this is simply the
removal of the faecal sac of the young. The Noisy Friarbird nest
near my house is cleaned by the adults regularly and frequently. After
they bring food, they usually pick up a deposited faecal sac and fly well away
from the nest with it. (I read in HANZAB that some birds, including Dusky
WS for the first days after hatching, eat the faecal sac.)
This is an amazing piece of evolution as the young of
nidicolous species deposit in sacs to permit this action by parents.
After fledging, the bird's physiology changes and the sacs disappear.
Apparently, because of the flimsy nests of the Woodswallows,
the parent removes the sac before it is dropped near the nest thus defeating
the purpose of the clean-up. HANZAB does not actually record such a
process of removal from the anus directly, from my quick scan of the
relevant pages.
Koel, Rosemary Blemings
koel, John Cummings
koel, Suzanne Edgar
koel, john braybrooks
