Hi folks, the following post is part of an ongoing discussion regarding the
local migration of robins. You may recall a previous posting from Michael
Price that included earlier comments, your comments on the following
discussion are most welcome.

**T.m.propinquus and T.m.caurinus are two subspecies of robins that are
known to occur along the west coast (when and where they occur and at what
concentrations is not completely understood)


>
>Hi Michael, long time no hear. I wanted to relate to you a few *tentative*
findings with respect to local robins. I have finally found concrete
examples of subspecies 'propinquus' and they have arrived most recently
whereas my perception is that the majority of the earlier migrants were
'caurinus'. Having looked at them on a few occasions there do appear to be
a few plumage differences worth looking for.
>
>#1--It is my perception that 'caurinus' is more solidly coloured,
particularly on the breast. 'propinquus' on the other hand (at least those
seen so far) seem to always have breast feathers that pale toward the
fringes (especially in the center of the breast) giving the breast a softer
less solid and slightly paler look (the females of this race are the palest
and are the ones that make some of us look twice since they may resemble the
eye-browed thrush).
>
>#2-- It is my perception that 'caurinus' has gray-tipped undertail coverts
whereas 'propinquus' has solid white undertail coverts. This appears to be
a consistent feature on the birds, that I was confident that I had correctly
ID'd to subspecies. It is possible that these feathers would be subject to
wear and would change over the course of a season and I don't know if
'propinquus' would have had gray-tipped undertail feathers earlier in the
season and they would wear later. So far in the limited sample that I have
observed this appears to hold as a means of separating these two subspecies
>
>#3-- 'propinquus' has white inner webs to the outer rectrices.
Fortunately, upon close observation this can be seen on the standing bird
and is certainly much easier to see on a bird in flight. The difficulty
with this feature, which I have encountered, is; if I can't see any white in
the tail does this mean it is 'caurinus'. You can well imagine the problem
here. Obviously white in the tail is definitive but lack of white may have
many meanings. So with this in mind, I have searched for other characters
like the two mentioned above.
>
>It would be so much easier if only we had a museum nearby!! Anyway, I have
found that these characters seem to work together fairly well so far.... In
other words, if a bird has gray-tipped undertail coverts they also appear to
lack white webs and have solid dark breasts. On the other hand, ones with
white in tail also have solid white undertail coverts and paling breast
feathers.
>
>Could it be this easy? I doubt it, since I have had such a relatively
small sample this could all be thrown out fairly easily. Much more time and
many more robins need to be put to this test. Tell me what you think...
>
cheers,

Don Cecile
dcecile at cln.etc.bc.ca