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CONSTRUCTION AND INSTALLATION OF HELLBENDER ARTIFICIAL NEST BOXES IN A TRIBUTARY OF THE WEST BRANCH SUSQUEHANNA RIVER

    Moore, Grace, Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA 17701, moograc@lycoming.edu; Kaunert, Matthew, Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA 17701, kaunert@lycoming.edu.

    The Eastern Hellbender (Cryptobranchus a. alleganiensis) represents an ancient lineage of giant (≤ 2.5 ft.), long-lived (> 25 years) stream-obligate salamanders endemic to the eastern United States. While considered indicators of stream habitat quality, hellbenders have experienced rapid range-wide population declines due to chronic nest failure. Habitat specialization on submerged rock slabs has imposed difficulties in monitoring efforts, resulting in historical information gaps in Cryptobranchid reproductive ecology. However, artificial nest boxes are an emerging conservation tool that provide a minimally-invasive technique for monitoring population trends and evaluating understudied aspects of hellbender reproduction. In this study, we constructed, installed, and monitored artificial nest boxes in a major tributary of the West Branch Susquehanna River. We constructed nest boxes using a 1:1 mixture of Portland cement and masonry sand using custom polyurethane rubber molds (910 Castings, Chardon, OH). In July – August 2024, we deployed nest boxes (N = 30) across two sites (15 nest boxes per reach) at high density (0.6 nest boxes/100m2 of wetted habitat). From August – September, we monitored rates of nest box occupancy, availability, and stability. We used underwater cameras to document occupancy and a BioMark HPR Plus PIT scanner to identify hellbenders occupying shelters. Within 30 days of installation, we detected shelter occupancy, several unique animals (n = 5), and high shelter availability (0.69). We also documented 100% shelter stability and an active hellbender nest established in September 2024. We will install additional nest boxes (N = 45) along a gradient of riparian forest cover in 2025. Future nest box monitoring efforts will evaluate factors influencing shelter performance, population trends, paternal care behaviors, and nest success within the watershed. This work will expand the scope of an existing artificial nest box monitoring framework in western Pennsylvania, allowing for broader evaluation of factors limiting hellbender recruitment and population persistence across the state.

    hellbender, habitat augmentation, reproduction, population monitoring