A Framework to Integrate Habitat Monitoring and Restoration with Endangered Insect Recovery

Abstract

Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify (e.g., insects) or when true recovery (delisting) requires continuous species-specific habitat management. In this paper, we outline and implement a standardized framework to facilitate the integration of habitat monitoring with species recovery efforts. The framework has five parts: (1) identify appropriate sample units, (2) select measurable indicators of habitat requirements, (3) determine rating categories for these indicators, (4) design and implement appropriate data collection protocols, and (5) synthesize the ratings into an overall measure of habitat potential. Following these steps, we developed a set of recovery criteria to estimate habitat potential and initially assess restoration activities in the context of recovering an endangered insect, the Karner blue butterfly (Lycaeides melissa samuelis). We recommend basing the habitat potential grading scheme on recovery plan criteria, the latest information on species biology, and working hypotheses as needed. The habitat-based assessment framework helps to identify which recovery areas and habitat patches are worth investing in and what type of site-specific restoration work is needed. We propose that the transparency and decision-making process in endangered insect recovery efforts could be improved through adaptive management that explicitly identifies and tracks progress toward habitat objectives and ultimate population recovery.

Using lidar to approximate keystone structure and evaluate management practices in potential habitats of the endangered Karner blue butterfly (Lycaeides melissa samuelis)

“…Over the past century, KBB's habitat has been steadily degraded or destroyed by human development and fire suppression policies (Kilgore, 1989;Nowa cki, 2008;Gifford et al, 2010). Therefore efforts to restore viable KBB populations prioritize the protection of critical habitat requirements and the ecological processes that sustain them (Bried et al, 2014).…”

“…The primary objective of habitat monitoring for the KBB is to focus on a set of environmental indicators that represent KBB's most critical requirements. One such indicator that accounts for a significant amount of management expenditure is vegetation structure, with particular emphasis on the shade heterogeneity that results from variations in canopy cover (Bried et al, 2014;).…”

“…The study site for this project the Albany Pine Bush Preserve, which is home to a globally rare inland pitch pine-scrub oak barren ecological community (Edinger et al 2014) in the capital region of upstate New York (Figure 1). It is one of the last remaining examples of this early-successional community type (Albany Pine Bush Commission, 2017), and is one of several KBB metapopulation recovery areas designated in the Glacial Lake Albany Federal Recovery Unit (Bried et al, 2014). The preserve's relatively small size (~1300 hectares), and proximity to dense urban centers (Albany and Schenectady) make it a prime example of the wildland-urban interface that is vulnerable to development pressure and habitat fragmentation.…”

“…Because shade is a direct function of canopy cover, it is frequently used as a proxy measure of shade Bried et al, 2014). As such, it is generally recommended that conservation planning for KBB habitat incorporate canopy heterogeneity and subsequent shade availability.…”

“…In their study of KBB movement patterns and population dynamics, more than 75% of movements were less than 100 m. This indicates that horizontally heterogeneous canopy should be available within a threshold adjacent area of at least 1 ha to sustain healthy KBB populations, which may reflect KBB's keystone structure. Providing a healthy mix of open grassland and forest also enables connectivity of KBB metapopulations, as dense forest can act as a barrier to their movement (Bried et al, 2014).…”