Nest initiation and end dates for eight grassland bird species in Wisconsin and Illinois

We used nest records from published grassland bird studies done in
Wisconsin and Illinois to compile a dataset for 8 obligate grassland bird
species Study sites were clustered in southwestern Wisconsin near Mt.
Horeb (43.0167°N, 89.7500°W); sites were located in Dane, Grant, Green,
Iowa, Lafayette, Monroe, and Rock counties. In northern Illinois, study
sites were located in Lee, Ogle, Will, Grundy, Carroll, and Jo Daviess
counties (40.9822 to 42.2356°N, -87.5433 to -90.3489°W).The dataset
consists of 3257 nests with observations on nest initiation date (date
first egg laid), nest fate (success, failure), number of fledglings, and
nest end date (date the nest either failed or fledged at least one
nestling). The species were Bobolink, Dickcissel, Eastern Meadowlark,
Grasshopper Sparrow, Henslow's Sparrow, Savannah Sparrow, Vesper
Sparrow, and Western Meadowlark.