Expanding the North American Breeding Bird Survey Analysis to Include Additional Species and Regions

Abstract

The North American Breeding Bird Survey (BBS) contains data for >700 bird species, but analyses often focus on a core group of ∼420 species. We analyzed data for 122 species of North American birds for which data exist in the North American Breeding Bird Survey (BBS) database but are not routinely analyzed on the BBS Summary and Analysis Website. Many of these species occur in the northern part of the continent, on routes that fall outside the core survey area presently analyzed in the United States and southern Canada. Other species not historically analyzed occur in the core survey area with very limited data but have large portions of their ranges in Mexico and south. A third group of species not historically analyzed included species thought to be poorly surveyed by the BBS, such as rare, coastal, or nocturnal species. For 56 species found primarily in regions north of the core survey area, we expanded the scope of the analysis, using data from 1993 to 2014 during which ≥3 survey routes had been sampled in 6 northern strata (Bird Conservation regions in Alaska, Yukon, and Newfoundland and Labrador) and fitting log-linear hierarchical models for an augmented BBS survey area that included both the new northern strata and the core survey area. We also applied this model to 168 species historically analyzed in the BBS that had data from these additional northern strata. For both groups of species we calculated survey-wide trends for the both core and augmented survey areas from 1993 to 2014; for species that did not occur in the newly defined strata, we computed trends from 1966 to 2014. We evaluated trend estimates in terms of established credibility criteria for BBS results, screening for imprecise trends, small samples, and low relative abundance. Inclusion of data from the northern strata permitted estimation of trend for 56 species not historically analyzed, but only 4 of these were reasonably monitored and an additional 13 were questionably monitored; 39 of these species were likely poorly monitored because of small numbers of samples or very imprecisely estimated trends. Only 4 of 66 “new” species found in the core survey area were reasonably monitored by the BBS; 20 were questionably monitored; and 42 were likely poorly monitored by the BBS because of inefficiency in precision, abundance, or sample size. The hierarchical analyses we present provide a means for reasonable inclusion of the additional species and strata in a common analysis with data from the core area, a critical step in the evolution of the BBS as a continent-scale survey. We recommend that results be presented both 1) from 1993 to the present using the expanded survey area, and 2) from 1966 to the present for the core survey area. Although most of the “new” species we analyzed were poorly monitored by the BBS during 1993–2014, continued expansion of the BBS will improve the quality of information in future analyses for these species and for the many other species presently monitored by the BBS.

Semi‐arid grassland bird responses to patch‐burn grazing and drought

“…McCown's longspur populations have been declining for the past 4 decades (Sauer et al ), with this species on the State of the Birds 2014 Watch List (http://www.stateofthebirds.org/2014/watch-list) and identified as a species of conservation concern by state wildlife management agencies throughout its range in the United States, by multiple federal land management agencies (U.S. Forest Service, Bureau of Land Management, U.S. Fish and Wildlife Service), and by the Canadian government.…”

Neural hierarchical models of ecological populations

“…To evaluate whether the results were consistent with previous findings that population persistence probabilities are highest in the center of a species' range, correspondence between BBS range centroids and persistence probabilities were also assessed using linear regression (Mehlman 1997;Royle & Kéry 2007). These qualitative analyses only used BBS routes surveyed in every year, and species that occurred in all years and at 100 or more routes to avoid bias associated with recently added Canadian routes, and variance associated with rare species (Sauer et al 2017).…”

Monitoring boreal avian populations: how can we estimate trends and trajectories from noisy data?

“…unequal among the different bird groups, and the information on shorebirds ( Fig. 4), waterbirds, birds of prey, and nocturnal species is particularly limited (Kirk and Hyslop 1998, Sinclair et al 2004, Hudson et al 2017, Sauer et al 2017b).…”