Secretive Marshbird Survey Report: Columbia NWR

Secretive marshbird surveys were initiated on Columbia National Wildlife Refuge (NWR) in 2003 and 2004, by Randy Hill, former refuge biologist. The surveys were started because the target species were not well detected by more standard bird survey techniques and a national protocol was being developed at the time. The data collected on Columbia was pooled with over 190 other stations and used to test the initial protocols (Conway and Nadeau, 2005) and to develop the final recommendations. The first national survey protocol for secretive marshbirds was issued in 2009 (Conway 2009) and it is now available as a USFWS approved national protocol framework (Conway and Seamans 2016). The data collected on Columbia NWR can also be pooled to inform national trends in marshbird populations. Transects were established as suggested by Conway and Nadeau (2005), but exact locations was at the discretion of the refuge biologist. Information on refuge-specific objectives of the survey, or how the surveyed transects and points were chosen was not documented or is now missing. Surveys were conducted in 2003 and 2004but not conducted again 2009. They were conducted sporadically through 2015 but the refuge discontinued the surveys in 2016 due to lack of staff and higher priority survey efforts. This report summarizes findings from secretive marshbird surveys conducted on Columbia NWR from 2003 to 2015. Although the initial objectives for establishing the survey were never specifically documented, the objective of this analysis is to document the survey effort and describe the secretive marshbird population on the refuge. In addition, refuge staff is interested in trend of secretive marshbirds in 2 units that receive intensive wetland management. American bittern (Botaurus lentiginosus) is a focal species for the marshbird survey protocol and also a management focal species for the refuge, representing emergent marsh habitat (USFWS 2011).