Hello to all,
My wife and I spent much of September travelling in far western NSW through
Nyngan, Cobar, White Cliffs, Tibooburra and on into Queensland out to the
Cooper and back to Kilcowera Station near Thargomindah.
Virtually all through that area we saw flocks of woodswallows - mainly Masked
with a few White-browed, but the sheer numbers were very impressive. Estimating
the numbers in big flocks is difficult, but in many cases there would have been
300-500 birds but in all
we must have seen tens of thousands of birds. Those on the move were roughly on
a south-easterley heading and at times when we were camped, towards evening,
there were flocks circling high overhead, apparently feeding before they
settled down for the night.
We saw no signs of nesting but when you are on the move, you tend not to.
Whilst on the subject of settling down for the night, despite trying I was
unsuccessful in observing any roosting - woodswallow flocks are extremely
flighty at roosting time and in all my time studying them I have only succeeded
once in observing White-browed and Masked Woodswallows at roost. They were NOT
clustering, but roosted singly, pressing themselves into the forks of a tree in
a more or less vertical position. The reason I dwell on this point is that the
"dark" woodswallows - Dusky, Little and Black-faced form a cluster roost every
night of their adult lives - this is well documented. All through the
literature it is stated that the migratory woodswallows cluster as well and
this stems from a single old record which I believe needs substantiation. I
believe they don't.
With so many woodswallows all over the place this year (they have now reached
coastal regions in some areas) I am hoping that by raising this issue, someone,
somewhere, will be lucky enough (or persevere) and watch them go to roost.
Incidentally, the term clustering is quite precise in its meaning - for true
clusters, look at my website under Black-faced and Little Woodswallows -
White-breasted Woodswallows do roost closely together in long lines but this is
not true clustering.
At one of our camps near Cobar we stayed several days and during that time they
were ever present - somewhat to my annoyance because I was trying to take tape
recordings and their incessant calling made recording difficult. However, I did
take a few pictures of groups of birds on dead trees warming in the early
morning sun, and not until we returned home and I was processing the pictures
did I notice the odd-looking bird - clearly a hybrid "Masked/White-browed", a
male with a black face like a Masked, and the deep vinaceous-brown underparts
of a male White-browed. I have put a picture up on my website under Masked
Woodswallow.
Over the years, I have seen many, many migratory woodswallows but never a
hybrid. A quick search of Birding-Aus archives revealed only one other record,
but a wider search by Google revealed a number of entries. By far the most
interesting of these is an extract
from the recent book "Boom and Bust : Bird Stories for a Dry country" wherein
Leo Joseph discusses hybridization in these two species - well worth reading. I
find it fascinating that such closely related species that spend virtually all
their lives in such close association, hybridize so rarely.
So, good luck and a Merry Christmas to you all - I am hoping to be overwhelmed
with replies, even to prove me wrong!
Graeme Chapman www.graemechapman.com.au
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