Date of this Version
Kroodsma, "Two Species of Marsh Wren (Cistothorus palustris) in Nebraska," from Nebraska Bird Review (June 1988) 56(2).
The consequences of a grand evolutionary experiment are evident throughout Nebraska. During the Pleistocene, many taxa were apparently separated into eastern and western populations. Today many of these eastern and western counterparts meet in the Great Plains, especially in Nebraska. Some pairs now hybridize freely (towhees. orioles. flickers), while others do not (buntings, grosbeaks, meadowlarks) (see Rising 1983).
The Marsh Wren is still another, previously unrecognized, taxon that consists of an eastern and western counterpart. Data from Nebraska and elsewhere in North America suggest that there are two forms of the Marsh Wren, perhaps as vocally different from each other as are the two Sternella meadowlarks. These two forms meet in Nebraska, and are perhaps sufficiently different and distinct that they should be called two separate species.