Evaluating Burrowing Behavior in the Devil Crayfish and its Importance for Conserving the Endangered Hine's Emerald Dragonfly
Habitat fragmentation, degradation, and destruction are some of the leading causes of species decline. For the Hine’s emerald dragonfly (Somatochlora hineana), habitat loss has been a main contributor to its federally endangered status. During the larval stages, these dragonflies seek refuge from drying and freezing periods in the burrows of their predator, the Devil crayfish (Cambarus diogenes). Cambarus diogenes create complex burrowing systems that can range from 0.25m to over 5m below the ground. It is understood that while the dragonfly larvae face the risk of predation, use of the burrows is vital for their persistence. Considering this unique predator-prey relationship, there is potential to increase S. hineana populations by augmenting the crayfish populations in depleted regions. Projects to captive rear C. diogenes have begun, but before we can introduce them into the S. hineana habitat, it is important that we study how to do so most effectively. We are exploring potential methods of introduction that encourage the crayfish to establish their burrow systems near the introduction point in laboratory mesocosms. Crayfish will be introduced to individual tanks filled with water and an artificial burrowing medium (Gelzan). Crayfish will be introduced, and video recorded in a tank with: 1) a premade hole, 2) a 25mm dowel, 3) a small terracotta pot, and 4) a control with Gelzan alone. If a burrow is created, we will analyze the time it takes to initiate burrowing, and determine which experimental arena is best suited for stimulating burrowing behavior. Based on observations of burrows in the field, we expect to see crayfish given an existing structure (such as the dowel or hole) will use it to facilitate burrow construction. These experiments will provide essential data for the creation of methodologies for the field introduction of captive reared C. diogenes.
Daniel A. Soluk
Tesar, Danielle, "Evaluating Burrowing Behavior in the Devil Crayfish and its Importance for Conserving the Endangered Hine's Emerald Dragonfly" (2020). IdeaFest. 143.