Bluffton Precast, Norwalk create hut for endangered Salamander.
The initial concept for the hut was designed by Jeffrey Briggler and John Ackerson, both of the Missouri Department of Conservation. In last year's article "Construction and Use of Artificial Shelters to Supplement Habitat for Hellbenders (Cryptobranchus alleganiensis)" in the Herpetological Review, Briggler and Ackerson noted that biologists had recognized a need to artificially propagate the Hellbenders to preserve/restore the species, and address the cause of their decline. "With limited success in locating eggs in the wild and need to supplement habitat in the wild, we designed artificial shelters that can be used by Hellbenders to meet their biological needs (e.g., shelter, nesting, etc.), thus, making eggs easier to find and harvest for propagation efforts," state the authors. Their design was constructed with wire mesh netting covered with concrete in a boot shape.
Gregg Lipps, an independent consultant to the Ohio Department of Natural Resources and partner in conservation with several zoos and nonprofit organizations, contacted Bluffton Precast Concrete, Bluffton, Ohio, to inquire if it was possible to make these huts using precast methods after encountering minor issues with the originals. In turn, Bluff-ton reached out to Norwalk Precast Molds. The precast design includes one additional feature not present in the original Briggler-Ackerson design: a 2-in. PVC sleeve in the top of the hut. This is capped when in place, but can be opened to insert a water quality meter or a camera, so that the huts can be probed for further research of the endangered species.
Lipps noted that they plan on placing 25 huts throughout Ohio, 10 in West Virginia, and six in New York this year (with various partners in each case). The number deployed is only limited by the funds available to purchase and install more huts. The huts will be partially buried into the substrate of the stream with the opening facing downstream, mimicking a cavity that would be found under a large slab rock or boulder in a creek or river.
The huts will also be used with captive-reared Hellbenders to investigate if there are benefits to a soft-release. "Our first release of captive-reared individuals occurred in 2012, and we found that the naive animals moved around a lot in the first 21 days, before settling down and behaving like wild Hellbenders," Lipps states. "Unfortunately, that increased movement also meant increased predation in the first 21 days. By enclosing captive-reared Hellbenders into the huts (and blocking off the entrance) for their first 10 days in the stream, we're hoping that they might adjust to their surroundings and increase their chances of surviving."
Lastly, Lipps hopes the huts can be used as part of mitigation projects to offset damage to streams. Siltation from development projects often results in the loss of refugia for Hellbenders, as the large rocks and their openings become smothered. Lipps plans to test the effectiveness of the huts at two restoration sites this year, one in Ohio and one with a colleague in West Virginia.
This project was funded by the Ohio Division of Wildlife, the Columbus Zoo, and the Toledo Zoo.