Subject: [Tweeters] phenomenon's to consider (re: Snowy Irruptions)
Date: Dec 17 22:48:19 2005
From: mike denny - m.denny at charter.net


Hello Gene,
It is a very good question.
That is one of my big questions, how did all these hundreds of "extra" raptors know about the microtine populations that currently fill the Walla Walla Valley. I would say that there are 3xs more raptors present than what is normally here. So how did they know??? How is it that all these black Red-tailed Hawks that do not nest here arrived and many times more Harlans Hawks than we normally see in a year. How did hundreds of harriers know to come here for the huge offering of microtine? Is it a fluke? I do not believe so. I think that there is a clue broadcast somehow that these raptors pick-up on to zero in on these cyclic events in rodent populations. I do not yet understand the "how", but I am working on it. What do you think? Our current lone sub-adult female Snowy Owl arrived during a huge microtine population explosion as did the last confirmed Snowy Owl in Walla Walla County, during the winter of 1996. Are these wintering raptor population shifts microtine inspired? Or are the raptors merely following innate internal code that dictates where and when they winter that just happens to match the high cycles in microtine populations in Southeastern Washington? One thing I think I know and that is microtine populations are directly tied to the amount of alfalfa acres planted in this valley. So do the whims/market forces on alfalfa farmers truly impact the raptor numbers arriving in this valley on any given winter? This is something I will think on tomorrow as I trudge through the ice encrusted vegetation on our CBC. Take care.
Later Mike

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Mike & MerryLynn Denny
1354 S. E. Central Ave.
College Place, WA 99324
509.529.0080 (h)

IF YOU HAVEN'T BEEN BIRDING, YOU HAVEN'T LIVED!
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