To Paul Taylor and Ronald Orenstein:
On Tue, 19 Aug 1997, Ronald Orenstein wrote:
> >2) Does anyone know why Eastern Yellow Robins cling to the side of small
> >trees, bushes, etc as oppose to perching "upright" on a branch while
> >foraging? Any thoughts on this would be welcomed.
>
> I don't know, but I have always assumed that birds that perch this way (and
> other robins do it too) may be surveying for a different range of insects
> from those that perch upright on branches - particularly for insects of
> lower strata and trunks. The extreme of this behaviour may be the
> "flushing" actions of Pied Monarchs.
Ronald: I have had similar thoughts, but I'v stopped and watched E.Y.
Robins foraging on several occassions and it doesn't seem that they are
taking prey from the trunks of trees (I'll continue watching). I like
Paul's idea that it is easier to spot insects on the ground if they cling
onto the side of a twig or tree -- my few observations in subtropical
rainforest habitat indicate that they most often take prey from the
ground, but other robins do as well and do not possess the habit of cling
to the side of trunks etc. If only vertical perches were available - in
grasslands as Paul's example illustrates with Scarlet and Hooded robins on
- then, of course, the birds will use them. In case of the E.Y. Robin,
howeveer, they seem to go one step further in that they prefer to cling
even though other perches are available as if the behaviour has become
ingrained into thier genes. Again. Paul suggests that in their natural
habitat clinging is the better options than perching upright. Ok, what is
their "natural" habitat? Could it be possible that E.Y. Robin in their
recent evolutionary past were tree-creepers in habit -- cling does seem to
be confine the genus Eopsaltria (and Tregellasia)? I frequently
scan back issues of Emu, etc. and I haven't come across in literature
covering the behaviour of robins.
Cheers, Jim
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