Evaluating Golden‐winged Warbler use of alder and aspen communities managed with shearing in the western Great Lakes

Abstract

Best management practices are often written by researchers to guide land managers and landowners in the creation of habitat for wildlife species of interest. These documents are based on research evaluating the habitat needs of a species, but they also describe tools and strategies managers can implement to create or restore desired conditions. Shrub and sapling shearing is a management practice often used to improve habitat for early-successional species, yet little monitoring or research has focused on wildlife response to shearing. The goal of this research was to formally evaluate the effect of shrub and sapling shearing as a best management strategy for Golden-winged Warbler (Vermivora chrysoptera) conservation at a regional scale. Specifically, we surveyed for male Golden-winged Warblers during the breeding season in sheared sites and untreated reference sites across portions of the western Great Lakes to assess the effects of (1) management status (i.e., sheared aspen or alder vs. untreated sites) and (2) patch-level vegetation characteristics on male abundance. We found that male Golden-winged Warbler abundance was twice as high in sheared sites than in mature reference sites and peaked when sapling cover was ~40%. Male abundance was also negatively associated with percent cover of forbs and nonvegetated ground. These findings highlight the importance of patch-level heterogeneity when implementing shearing treatments for Golden-winged Warblers and demonstrate the potential need for pretreatment site assessments to help focus conservation efforts for this species. Ultimately, our results support the use of a site-specific, nuanced approach to shearing implementation to maximize cost efficiency and desired species outcomes.

Assessing American woodcock use of habitat managed through programs targeting a declining songbird

“…This is especially true when young forest (a high‐density cover type) is created from mature forest (a low‐density cover type; Dwyer et al 1983, Nelson and Andersen 2013). Future work that quantifies woodcock density in untreated habitat, especially untreated shrublands (Buckardt‐Thomas et al 2023), would help clarify the absolute value of warbler habitat to American woodcock populations.…”

Breeding season space use and habitat selection by Blue-winged Warblers in managed shrublands

“…Assessing avian species responses to young forest and shrubland management is important to describe effectiveness of and identify ways to improve conservation actions (i.e., Boves et al 2013, Akresh et al 2015, Buckardt Thomas et al 2023). As such, several eastern shrubland bird species have been the focus of studies seeking to assess response to habitat management (Zuckerberg and Vickery 2006, Akresh et al 2015, Bakermans et al 2015.…”

“…This Nearctic-Neotropical migratory passerine breeds in early successional woody communities of the eastern United States and southern Canada and has experienced population declines in several Bird Conservation Regions, such as the Piedmont and Mid-Atlantic Coast (Sauer et al 2019, Gill et al 2020. Studies examining Blue-winged Warbler response to habitat management are uncommon relative to the wealth of research attention paid to its congener, the Golden-winged Warbler (V. chrysoptera), which is experiencing an annual population decline of nearly 2% (Sauer et al 2019, Fiss et al 2021, Buckardt Thomas et al 2023. In fact, much of what is known about Blue-winged Warbler breeding ecology comes from studies that compared both Vermivora species in areas of sympatry, typically in the context of how Blue-winged Warbler presence may negatively impact Golden-winged Warblers via hybridization and/or competition (Confer and Knapp 1981, Confer et al 2003, Confer et al 2010, Patton et al 2010.…”

“…Light Detection and Ranging (LiDAR) is another technology that can align the scale at which habitat features are measured with the scale at which individual selection behavior occurs (Hardiman et al 2018, Shanley et al 2021. Although field surveys can provide useful information about Vermivora space-use patterns, LiDAR data have been demonstrated to perform better in describing certain aspects of habitat structure (McNeil et al 2023). However, other important aspects of habitat, like plant species composition (Bellush et al 2016) would require field surveys, as LiDAR cannot provide this information.…”

“…Importantly, LiDAR-derived variables can be used to describe structural attributes of a species' habitat (e.g., variation in vegetation height and density) that are difficult to quantify by many other remotely sensed data or field-based vegetation sampling protocols. As such, the increased availability of LiDAR data has provided researchers with the ability to quantify and map vegetation structure for target species, and thus better inform conservation and management decisions (McNeil et al 2023).…”