| Abstract: | The Singing-Ground Survey (SGS) is a primary source of information on population change for American woodcock (Scolopax minor). We analyzed the SGS using a hierarchical log-linear model and compared the estimates of change and annual indices of abundance to a route regression analysis of SGS data. We also grouped SGS routes into Bird Conservation Regions (BCRs) and estimated population change and annual indices using BCRs within states and provinces as strata. Based on the hierarchical model?based estimates, we concluded that woodcock populations were declining in North America between 1968 and 2006 (trend = -0.9%/yr, 95% credible interval: -1.2, -0.5). Singing-Ground Survey results are generally similar between analytical approaches, but the hierarchical model has several important advantages over the route regression. Hierarchical models better accommodate changes in survey efficiency over time and space by treating strata, years, and observers as random effects in the context of a log-linear model, providing trend estimates that are derived directly from the annual indices. We also conducted a hierarchical model analysis of woodcock data from the Christmas Bird Count and the North American Breeding Bird Survey. All surveys showed general consistency in patterns of population change, but the SGS had the shortest credible intervals. We suggest that population management and conservation planning for woodcock involving interpretation of the SGS use estimates provided by the hierarchical model. |
| Genre: | Article |
| ProdID: | 5224851 |
| Citation Author: | Sauer, J.R.; Link, W.A.; Kendall, W.L.; Kelley, J.R.; Niven, D. K. |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 214 |
| Citation Issue: | 1 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Journal of Wildlife Management |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 11 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | 204-214 |
| Citation Projection: | |
| Citation Public Comments: | 6895_Sauer.pdf |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | A hierarchical model for estimating change in American Woodcock populations; 2008; Article; Journal; Journal of Wildlife Management; Sauer, J.R.; Link, W.A.; Kendall, W.L.; Kelley, J.R.; Niven, D. K. |
| Citation Start Page: | 204 |
| Citation Volume: | 72 |
| Citation Year: | 2008 |
| Type: | citation/reference |
| Text: | A hierarchical model for estimating change in American Woodcock populations; 2008; Article; Journal; Journal of Wildlife Management; Sauer, J.R.; Link, W.A.; Kendall, W.L.; Kelley, J.R.; Niven, D. K. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DOCUMENT): | http://www.bioone.org/doi/abs/10.2193/2006-534 |
| Date Other: | Wed, 16 Jun 2010 12:18 -0500 |
| Publisher: | |
