DOI: 10.5061/dryad.cjsxksnb8
title: Nest initiation and end dates for eight grassland bird species in Wisconsin and Illinois

description: 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. 
description: Nest data from all studies were put into a common format of nest
 initiation date (date first egg laid), nest fate, number of nestlings, and
 nest end date (date the nest either failed or fledged at least one
 nestling). We used the fate (success or failure) as assigned by the
 original researchers. We used the nest initiation and failure dates if
 recorded by the original researchers. In general, nest initiation dates
 were estimated based on field notes or digital video (i.e.,
 video-surveillance of nests). In some instances, nests failed within the
 same nesting stage (laying, incubation, or nestling) in which they were
 first found. For these cases, nest initiation dates were estimated
 following Cox et al. (2012. Species and temporal factors affect
 predator-specific rates of nest predation for forest songbirds in the
 Midwest. Auk 129:147–155) using average species-specific incubation times
 from Ehrlich et al. (1988. Birder’s handbook. Simon and Schuster Inc. New
 York, New York, USA). Nest end dates (date when nest failed or fledged at
 least one nestling) were either known (e.g., forced fledging during nest
 checks, digital video, field observations) or estimated. Nest end date was
 estimated using the mid-point between the dates when the nest was last
 observed with eggs/nestlings present and when the nest was next observed
 empty. We used the data to estimate the potential species-specific impacts
 of disturbance (e.g., mowing, fire) conducted at different dates in the
 breeding season on nests and fledglings.
description: # 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 (43.0167N, 89.7500W); 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 42.2356N, -87.5433 to -90.3489W).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. Nest data from all studies were put into
 a common format of nest initiation date (date first egg laid), nest fate,
 number of nestlings, and nest end date (date the nest either failed or
 fledged at least one nestling). We used the fate (success or failure) as
 assigned by the original researchers. We used the nest initiation and
 failure dates if recorded by the original researchers. In general, nest
 initiation dates were estimated based on field notes or digital video
 (i.e., video-surveillance of nests). In some instances, nests failed
 within the same nesting stage (laying, incubation, or nestling) in which
 they were first found. For these cases, nest initiation dates were
 estimated following Cox et al. (2012. Species and temporal factors affect
 predator-specific rates of nest predation for forest songbirds in the
 Midwest. Auk 129:147155) using average species-specific incubation times
 from Ehrlich et al. (1988. Birders handbook. Simon and Schuster Inc. New
 York, New York, USA). Nest end dates (date when nest failed or fledged at
 least one nestling) were either known (e.g., forced fledging during nest
 checks, digital video, field observations) or estimated. Nest end date was
 estimated using the mid-point between the dates when the nest was last
 observed with eggs/nestlings present and when the nest was next observed
 empty. We used the data to estimate the potential species-specific impacts
 of disturbance (e.g., mowing, fire) conducted at different dates in the
 breeding season on nests and fledglings. ## Description of the data and
 file structure Data were put into an Excel file. The first line of the
 file is the header followed by 3257 lines of data. There are 10 columns.
 The columns are as follows. Nest\_ID = unique nest identifier State =
 State in which nest was located (Illinois or Wisconsin) County = County in
 the state in which nest was located Habitat = Grassy habitat in which nest
 was located (pasture, cool-season grassland, warm-season grassland, or
 prairie) Species = English common name Year = Year nest was found
 Nest\_Fate = Successly fledged at least one young (1) or Failed (0).
 Initiation\_Date = Coded date when the first egg was laid. April 1 = 1;
 May 1 = 31; June 1 = 62; July 1 = 92; August 1 = 123; September 1 = 154
 Number\_Fledged = For a successful nest, number of young in nest on nest
 end date; For a failed nest, Number\_Fledged is 0 Nest\_End\_Date = Coded
 date when the nest failed or was successful. April 1 = 1; May 1 = 31; June
 1 = 62; July 1 = 92; August 1 = 123; September 1 = 154 ## Sharing/Access
 information Data were derived from the following sources: * Basili, G. D.
 1997. Continental-scale ecology and conservation of Dickcissels.
 Dissertation, University of WisconsinMadison, Madison, Wisconsin, USA. *
 Byers, C. M., C. A. Ribic, D. W. Sample., J. D. Dadisman, and M. R.
 Guttery. 2017. Grassland bird productivity in warm season grass fields in
 southwest Wisconsin. American Midland Naturalist 178:4763. * Ellison, K.
 S., C. A. Ribic, D. W. Sample, M. J. Fawcett, and J. D. Dadisman. 2013.
 Impacts of tree rows on grassland birds and potential nest predators: a
 removal experiment. PLoS ONE 8(4):e59151.
 https://doi.org/10.1371/journal.pone.0059151. * Herkert, J. R., Reinking,
 D. L., Wiedenfeld, D. A., Winter, M., Zimmerman, J. L., Jensen, W. E.,
 Finck, E. J., Koford, R. R., Wolfe, D. H., Sherrod, S. K. and Jenkins, M.
 A. 2003. Effects of prairie fragmentation on the nest success of breeding
 birds in the midcontinental United States. Conservation Biology 17:587594.
 * Renfrew, R. B., C. A. Ribic, and J. L. Nack. 2005. Edge avoidance by
 nesting grassland birds: a futile strategy in a fragmented landscape. The
 Auk 122:618636. * Ribic, C. A., M. J. Guzy, T. A. Anderson, D. W. Sample,
 and J. L. Nack. 2012. Bird productivity and nest predation in agricultural
 grasslands. Studies in Avian Biology 43:119-134. * Temple, S. A., B. M.
 Fevold, L. K. Paine, D. L. Undersander, and D. W. Sample. 1999. Nesting
 birds and grazing cattle: accommodating both on Midwestern pastures.
 Studies in Avian Biology 19:196202. * Vos, S. M., and C. A. Ribic. 2013.
 Nesting success of grassland birds in oak barrens and dry prairies in West
 Central Wisconsin. Northeastern Naturalist 20:131–142.