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Hi Mike,
Regarding: "a small flock of Eurasian Tree
Sparrows .... about 10 birds in all, all males."
I doubt that they were all males. That would be
odd. There is no way of sexing them. Eurasian Tree Sparrows are odd, (I suspect
unique), among the many members of the genus Passer, in that not only
are the sexes identical in appearance (both in summer and winter phases) but
females resemble the typical males of the genus, i.e. both sexes of the Tree
Sparrow look like the males (not females) of other species of Passer,
in terms of species distinctive head patterns and overall richer colouration
than females. It is normal when odd species are sexually monomorphic in a group
that is mostly sexually dimorphic, that both sexes resemble the typical female,
rather that the typical male (think of Grey Teals as a good
example).
When I did my honours year studying social behaviour of these
critters (in comparison with House Sparrows), my supervisor wanted me to look
inside them after I had finished the relevant observations, to determine what
sex each bird was. I ended up not doing that.
Philip
-----Original Message-----
From:
Mike Simpson <>
To:
Birding-Aus (E-mail) <>
Date:
Sunday, 18 January 2004 15:52
Subject: [BIRDING-AUS] Tree
Sparrows and Spangled Drongo in Penrith
Had a great deal
of twittering in the garden in Penrith this morning, and on
investigation
there was a small flock of Eurasian Tree Sparrows on our
washing line and
in the shrubs, about 10 birds in all, all males. I went to
get my camera,
and as usual they all moved off as soon as I opened the door.
I put out
some bread crumbs hoping to draw them back, but all I got were the
usual
house sparrows and Spotted TurtleDoves.
How common are Tree Sparrows
in the Sydney area? I can not remember noticing any here in the past. Their
nice brown heads were clearly visible as they were only about 10ft from my
window.
Best regards - Mike
Penrith, NSW,
Australia
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