Michael,

However, it appeared following a bit of a cold snap (for October) and is in
a location where they often winter.

Gene.

At 10:10 PM 10/16/97 -0700, you wrote:
>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
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