The USFWS this week announced the historic discovery of two active Kirtland's Warbler nests in central Wisconsin. One contains four eggs, and there appears to be at least three females in the area. The nests are the first to be located here in the Badger State and the first outside Michigan since a single nest was recorded in Ontario in 1944.
Fascinating. And the big story, as Paul Kerlinger reported in our June 2007 issue ("On the Move," p.62, pictured at left), is just as interesting:
As I'm sure you know, the population of Kirtland's Warblers in the core breeding range in northern lower Michigan has increased dramatically since 1987. In fact, their numbers rose in 10 of the 11 years between 1989 and 2000. The growth was consistent enough to make researchers speculate that the birds might soon run out of room and start looking for suitable habitat outside the core breeding range. And it looks like that's what's happening:
Between 1978 and 2000, 90 males and 38 females were found in the Upper Peninsula. The first breeding record outside the core range came in 1995, at Baraga Plains. Researchers documented 25 additional nesting attempts in the UP between 1995 and 2000. Ten nests are known to have fledged young.
The number of males found in Wisconsin between 1978 and 2000 was 25, and they've been observed in each of the past two years, but until this spring, there had been no nests.
Worth noting, too, is that three males were observed singing near Petawawa, Ontario, last year, suggesting that the birds are heading east as well as north and west after making that long flight from Eleuthera. And wouldn't you know it? A warbler banded at Petawawa last year returned there this year.
Also in our field of view this week:
- A judge struck down Delaware's two-year ban on harvesting horseshoe crabs in Delaware Bay, regardless of how much it would benefit Red Knots and other hard-pressed shorebirds. Delaware 's environmental secretary said the ruling represented a "debatable legal decision by the
court and a lousy environmental decision for the state.”
- The Fish & Game Commission announced that hunters won't have to use non-lead ammunition for big-game and varmint hunting this fall, regardless of how much it would benefit California Condors. The commission intends to take action on a proposed ban at a July 13 meeting in Bridgeport.
- And the National Audubon Society, regardless of how satisfied we feel about the Kirtland's Warbler, reminded us that populations of 20 common North American birds have plummeted since 1967. --C.H.
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