Are avian population targets achievable through programs that restore habitat on private‐lands?

Abstract

AbstractAgricultural intensification has negatively affected biodiversity throughout the world. In the United States, population declines of many early successional bird species have been linked with habitat loss due to agriculture. In light of this, recent efforts have attempted to prioritize conservation actions at continental scales. Importantly, these efforts have used existing data to estimate the global population size for declining species and set future population goals. Though these efforts consider broad scales for conservation efforts and provide population targets, they lack explicit plans to achieve established goals. One way to achieve these population goals is through the process of habitat restoration, such as voluntary private‐land conservation programs that restore habitat in agricultural landscapes and are implemented at a sufficiently large scale to achieve population goals. Our goal was to understand how private‐land conservation programs can be used to achieve population goals for declining species. To do this, we examined the population‐level impacts of the Conservation Reserve Enhancement Program, a program that has created more than 57,000 ha of restored habitat in Illinois, for four declining conservation priority species, the Bell's Vireo (Vireo bellii bellii), Field Sparrow (Spizella pusilla), Northern Bobwhite (Colinus virginianus), and Willow Flycatcher (Empidonax trailli trailli). We surveyed 172 randomly chosen restored fields in 10 counties in central and west‐central Illinois during the 2012–2015 breeding seasons. We found that current private‐land conservation efforts in Illinois are probably effective in achieving state population goals for rare species with restricted habitat preferences such as the Bell's Vireo and may be close to achieving the goal for the Willow Flycatcher. However, more than 10 times the current amount of restored habitat (~1% of land used for agriculture in Illinois) would be required to achieve the population goals set for all of our focal species. Our results suggest that achieving population goals for early successional bird species using land restored through private‐land programs may be possible for some rare species, but the large amount of habitat needed for many species makes achieving these goals only possible with significant increases in private‐land habitat.