Hi Birders,
Here's another example of Blackbirds occurring away from towns: they are
common in River Oak woodland along the Coxs River, surrounded by
agricultural (grazing) land just west of the Blue Mountains. I have also
seen them around the edges of pine plantations, far from any towns on the
Newnes Plateau.
Regarding displacement of the Bassian Thrush. In the Blue Mountains, any
such impact would most likely occur in native bushland on the fringes of
towns, especially the wetter forests favoured by the thrush - a situation
in which Blackbirds can all too often be found. My gut feeling is that
Bassian Thrushes have declined in areas like this, but (as Lawrie
suggested) it would be difficult to establish whether any such decline is
due to competition from Blackbirds or from other factors, such as
introduced predators, weed invasion or changed fire regime.
Although both species are reasonably common in the Blue Mountains, I cannot
think of any location - off the top of my head - where Blackbirds and
Bassian Thrush can be regularly found together, but I will check my
notebooks and put the question to Blue Mountains Bird Observers. Does
anyone else on this list know of anywhere they happily coexist?
Carol
Carol Probets
Katoomba NSW
---------------------
>Max O'Sullivan wrote:
>
>> They certainly seem to only settle in towns and I
>> have never seen them in anything but gardens over the years. So they
>> don't seem to displacing any native species. Any comments?
To which Lawrie Conole replied:
>
>Down here in the Deep South (Victoria and Tasmania), Blackbirds
>certainly do occur commonly in native vegetation. It always surprises
>me to see them scooting across lawns in Mallee towns in Victoria, but
>that's a common enough scene through a lot of Victoria now from the
>humid coastal areas through to the semi-arid inland. They are found in
>most forest areas in southern Victoria to some extent, and I've seen
>them in far south-west Tasmania. More recently I've recorded them in
>granite rise shrubland surrounded by Callitris in Terrick Terrick
>National Park on Victoria's Northern Plains - a relatively dry landscape
>(and during drought). They're still conquering new ground even down
>here.
>
>As to whether they compete with native species - not sure. Bassian
>Thrushes used to occur in Geelong suburbs back in the early 1900s. The
>fact that they disappeared may have been due to other factors than
>competing Blackbirds and Song Thrushes??????? I'm not aware of any data
>on the impact of Blackbirds on species like the Bassian Thrush. Do such
>data exist?
>
>L.
>
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
|
