Hi Tweets,

Reto Riesen writes, possible Red-breasted Sapsucker migration:

>Maybe I disagree for once with Michael. 2 winters ago, end of January
>96, there were suddenly Red-breated Sapsucker around UBC where there were
>none before. I do the same walk quite regularly through winter, and
>suddenly I saw 2 to 6 sapsuckers a day, for a 5 day period. (i.e. 6
>RBSA's on a 500m stretch. This was a) in the middle of winter
>b) after a cold spell. It might be difficult to distinguish residents
>from migrants up in Cypress Bowl,but down here: you know when they are
>here.
(snip)

That's true, Reto, in winter. My suggestion is that the birds from northern
BC go through earlier than winter: if you only make this walk in winter, and
see them then, I'd agree, they'd be birds from high up that come down to sea
level not when the cold snap begins but after the sap freezes as far down as
the roots (the timing was pointed out by Dick Cannings). No disagreement there.

But if you do this walk *only* in winter, Reto, you'll miss any which
migrate through from late summer to late fall: their southbound migration
window will have opened and closed by the time you begin your walks. If,
however, you make this walk each day between August and May, my hunch is
that you'd see a small number of southbound birds showing up in Sep-Oct and
northbound birds late March-early May each year regardless what the local
weather is, and their southbound appearance may likely be speeded by the
first good hits of cold in the northern part of the province.

In Birds of BC, Campbell et al say: "Movements from the breeding areas to
wintering areas are difficult to discern (I'll say--m), but it is unusual to
find Red-breasted Sapsuckers anywhere in the Interior after August. Southern
Vancouver Island records begin to increase in early September suggesting a
return of the birds from their breeding areas."

I'll propose that the regional pattern suggests that Martin's bird was as
equally possible a southbound migrant as a local bird; as one swallow
doesn't make a summer, one sapsucker doesn't freeze sap in the trees of the
local mountains. '-)

Michael Price We aren't flying...we're falling with style!
Vancouver BC Canada -Buzz Lightyear, Toy Story
mprice at mindlink.net