Yes it is remarkable that "birds weighing less than 9g are so oblivious
to overnight temperatures of -6°C and are prepared to begin incubating
eggs under these conditions". But then again, sitting overnight, maybe
close to your best friend (I don't know if Thornbill pairs roost
together) in a nicely made nest with sides and a roof, maybe lined with
grass or fluff or extra insulating feathers, is very likely to be more
comfortable than perched exposed on a eucalypt twig with no protection
at all from the cold, wind and maybe rain. And yes, starting early
probably does help reduce the risk of predation and parasitism.
Philip
-----Original Message-----
From: Milburns
Sent: Thursday, 28 July 2011 11:40 PM
To: Canberra Birds
Subject: Early Spring at Mulligan's Flat
It may be mid-winter at Carwoola but spring was very much in the air at
Mulligan's Flat this morning.
Brown and Yellow Thornbills have been nesting for several weeks already
and today Buff-rumped and Striated Thornbills were busy in nest
construction mode. No cuckoos in evidence but they really were missing
out because even an amateur like myself found several nests without too
much effort.
There are few Pied Currawongs and essentially no cuckoos in evidence at
present so I suppose there is a clear advantage to nesting so early in
that respect. However, it never ceases to amaze me that birds weighing
less than 9g are so oblivious to overnight temperatures of -6°C and are
prepared to begin incubating eggs under these conditions. Some
resonance here with Geoffrey Dabb's observations from Gluepot but those
honeyeaters are great clunkers by comparison to thornbills.
Interestingly, the prognostications for next week are for unseasonally
warm weather! I'm looking forward to it.
Milburn
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