Assessing Roadside Bias and Detectability in Grassland Bird Surveys

Assessing Roadside Bias and Detectability in Grassland Bird Surveys

A potential downside of roadside surveys is that results may not be representative of areas far from roads.  The North American Breeding Bird Survey (BBS) is the primary source of information on grassland bird population size and trends, but how two critical assumptions (roadside bias, detectability) of the BBS apply to grassland birds in the Northern Plains is poorly known.  Project objectives are to assess occurrence and detection of grassland birds in relation to roads as well as evaluate seasonal timing of surveys, both of which have been identified as critical information gaps.  The results will allow conservation partners to calibrate BBS results, better estimate population size, and guide population monitoring, which will improve inferences made from spatial models used to guide grassland bird conservation, as well as increase confidence in population data used in Endangered Species Act listing decisions.

Partners: USGS Northern Prairie Wildlife Research Center, USFWS Region 6 Inventory and Monitoring Program, HAPET office.