Effects of broadcasting calls during surveys to estimate density and occupancy of northern bobwhite
Date
2012-03-23
Journal Title
Journal ISSN
Volume Title
Publisher
Wildlife Society Bulletin
Abstract
We assessed the effects of using a broadcast caller during surveys and increasing survey duration to estimate northern bobwhite (Colinus virginianus) density and occupancy. From 15 May 2009 to 15 August 2009, we conducted repeat-visit breeding bobwhite surveys at 180 sites in Delaware, USA. Increasing survey duration from 3 min to 7 min, or using a broadcast caller, improved detection probability for a single visit by 52% and 42%, respectively. However, density estimates when using a broadcast caller were biased high—≥3 times greater compared to passive-listening surveys. Density estimates for 3-min and 7-min passive surveys were not different. Additionally, bobwhite occupancy was similar among all 3 survey treatments. Use of a broadcast caller to survey for bobwhites appears to violate the assumption of distance sampling that an individual is detected prior to movement. Use of a broadcast caller is inappropriate for determining density estimates through distance sampling, but may be appropriate for determining site occupancy. © 2011 The Wildlife Society.
Description
This article was originally published in Wildlife Society Bulletin. The version of record is available at: https://doi.org/10.1002/wsb.82
Keywords
call playback, Colinus virginianus, distance sampling, northern bobwhite, occupancy, life on land
Citation
Duren, K.R., Buler, J.J., Jones, W.L. and Williams, C.K. (2012), Effects of broadcasting calls during surveys to estimate density and occupancy of northern bobwhite. Wildlife Society Bulletin, 36: 16-20. https://doi.org/10.1002/wsb.82