Date of this Version
Silcock, “Summer Field Report, June-July 2007,” from Nebraska Bird Review (September 2007) 75(3).
This summer was a "something for everyone" season. Ecologists, already excited by the apparent ability of Greater Prairie-Chickens to lek in improbable habitats, such as corn fields and dirt edges of Rainwater Basin playas, will welcome the use by Lark Buntings and Vesper Sparrows of wheat stubble fields with a growing corn crop. The Vesper Sparrows of the east, a different subspecies from those in the north and west, have been at the mercy of full-tillage cropping systems, but now have a reprieve and may even be increasing because of no-till and minimum tillage methods currently in vogue due to high fuel prices and conservation benefits.
White-faced Ibis again nested in several places, and Red-shouldered Hawk is showing signs of expanding from its limited range at Fontenelle Forest. Very exciting was the confirmation of breeding for the first time in Nebraska of Ash-throated Flycatcher, only the second record of the species' occurrence in the state. Hopefully confirmation is soon to follow for Broad-tailed Hummingbird, which has now twice been reported during the breeding season.
A phenomenon that may be applicable to those early migrant passerines that appear well before local breeders seem to have finished breeding and have even contemplated migration, is molt-migration. A recent article in Birding (http://www.americanbirding.org/pubs/birding/archives/vol39no3p34to40.pdf) discusses this strategy for such species as Dusky Flycatcher, Warbling Vireo, Western Tanager, Lazuli Bunting, and Bullock's Oriole, which is probably best known for its early departure from breeding areas for an intermediate staging area where it molts, and then continues to its wintering grounds. The possibility was raised by Ted Floyd that Chipping Sparrow might be in this group as well.
Unfortunately, other than the existence of many such rather early fall records for various species in areas where breeding does not occur, Nebraska has little data to support or contradict this idea. Observers should continue to report obvious indications of early fall movement (flocking, appearance out of breeding habitat, disappearance of adults).