The recent discovery of 2-3 Nelson's sparrows is a wonder. I checked
histograms of departure and arrival dates on the wintering and breeding
grounds, and they are expected to leave their wintering grounds along
the coast from southern new England in mid-May and by early May in South
Texas, then arrive in Canada's prairie marshes in late May or early
June. Such has been our understanding for 150 years, anyway.
        Peterjohn (p 502) writes of Ohio that they were 'largely undetected'
here before 1960, and have been accidental migrants away from the
Lakefront. Ohio is a fly-over along the northern portion of the
migratory pathway, with probably only a smidgen of them passing through
here (see the maps). As for their distribution in the state, it makes
sense that migrating marsh birds that prefer, other things being equal,
to fly over terra firma can be expected to concentrate in Lake Erie's
wetlands.
        Peterjohn considers Ohio's earliest confirmed report one from 8-9 May,
with most reports having come from 15-28 May. A report of sharp-tails at
an inland marsh on 22-23 March is doubly stunning. I know we've had an
extraordinarily early "spring" (quot marks in view of a low of 31
degrees F forecast for Monday night in Funk), and I know  birds that
winter mostly in the US, like this one, are more likely to respond to
encouraging US weather with early departures, but to have these birds in
an inland marsh ~TWO MONTHS ahead of their normal schedule tests the
limits of imagination.
If they reach the breeding grounds two months early, will they survive?
Will they stay here for a while? If the weather remains warm, will they
stay to raise another brood up north? Do only a small number of
individuals migrate so early, seeking an advantage by testing the harsh
realities of early spring? Have they been doing this for thousands of
years, and only recently have we noticed it? Is there some rogue
chemical in the water? If any readers have plausible theories, please
share...
Bill Whan
Columbus

______________________________________________________________________

Ohio-birds mailing list, a service of the Ohio Ornithological Society.
Our thanks to Miami University for hosting this mailing list.
Additional discussions can be found in our forums, at www.ohiobirds.org/forum/.

You can join or leave the list, or change your options, at:
http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS
Send questions or comments about the list to: [log in to unmask]