Elsewhere in this blog, I have written about the difficulties in identifying Eastern and Western meadowlarks, both by plumage and by song. It does not help that both species occasionally learn each other’s song. The two species also hybridize, although the offspring of these birds are often sterile (Jaster et al. 2012).
Nevertheless, this individual, singing last spring near Circle Lake in Rice County, went down i my field notes as an Eastern Meadowlark. According to my first Peterson guide (available for a penny from Amazon.com), the Eastern sings "two clear slurred whistles, musical and pulled out: tee-yah, tee-yair (last note 'skewy' and descending)." The Western, on the other hand, sings "a variable song of seven to ten notes, flute-like, gurgling, and double-noted; very unlike clear slurred whistles of Eastern Meadowlark.” A South Dakota friend translates this call to "Have you planted your wheat yet?"