TexBirders--Joe Kennedy's remark that it is hard to discern Blue Jay migration in an area like urban Houston reminded me of some research I had done back in the mid-1980s: I compiled selected CBC data in the area along the I-35 corridor (Waco, Austin, San Antonio) which was--at that time--in the general vicinity of the western edge of the Blue Jay's "natural range" in upland and riparian woodlands. This was in conjunction with my graduate studies of the impacts of urbanization on bird populations. If I recall correctly, I went back about 20 or 25 years (the period of record for useful CBC data) to see if I could see trends of several urban-adapted or urban-adapting species. One of the interesting tidbits that I noted was a fairly regular cycle of Blue Jay influxes about every 4 to 6 years in that particular region. I took those spikes to be the periodic immigration of migrant Northern Blue Jays.
That tangent to my other graduate research never got published but perhaps it's time to dust off that data, update it, and see (a) if those trends have continued, and (b) if they might be of any utility for gaging WNV impacts. I'll let you know when/if I can find that old cardboard box with era graduate era data in it.
Chuck Sexton Austin, TXEdit your Freelists account settings for TEXBIRDS at http://www.freelists.org/list/texbirds
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