Moore, J. D., T. R. Cooper, R. Rau, D. E. Andersen, J. P. Duguay, C. A. Stewart, and D. G. Krementz. 2019. Assessment of the American Woodcock Singing-Ground Survey zone timing and coverage. Pages 181-192 in Krementz, D.G., D. E. Andersen, and T.R. Cooper (eds.). Proceedings of the 11th American Woodcock Symposium, University of Minnesota Libraries Publishing, Minneapolis, Minnesota, U.S.A. DOI:10.24926/AWS.0124.
Abstract
The American woodcock (Scolopax minor) Singing-Ground Survey (SGS) was developed to inform management decisions by monitoring changes in the relative abundance of woodcock. The timing of the designated survey windows were designed to count woodcock that have settled in an area while minimizing the counting of migrating woodcock to the best extent possible. Since the implementation of the SGS in 1968, concerns over survey protocols that may bias data have been raised and investigated; however, the extent of survey coverage , the timing of the survey window zones, and whether double counting might occur within and among survey zones have not been critically investigated We used three years of data collected from satellite-marked male and female woodcock to assess the timing of the SGS survey windows and to what extent there was potential to double count woodcock among the survey zones. SGS coverage encompassed the majority of woodcock breeding-period sites within the U.S. (n = 17, 92%) and approximately half of the breeding period sites in Canada (n = 6, 43%). Thirteen of the 37 monitored woodcock with known breeding-period site arrival dates (35%) were migrating through a survey zone during an active survey window, all in the northernmost four out of five SGS zones. Thirteen woodcock arrived at breeding period sites after the start of surveys, all but one with breeding-period sites in the northernmost two zones. The combination of these situations may result in the SGS weighing too heavily the contribution of routes in southern portion of the primary breeding range while weighing too lightly the routes in the northern portion of the primary breeding range. We believe that we have demonstrated enough concerns about zone window timing to suggest that additional information is necessary to evaluate whether current zone window dates are sufficient, or whether they need to be changed.