The Impact of Management on the Movement and Home Range Size of Indiana’s Eastern Hellbender Salamanders Emily B. McCallen, Bart T. Kraus, Nicholas G. Burgmeier, and Rod N. Williams Department of Forestry and Natural Resources GIS Processing Results Hellbenders in Indiana Large, fully aquatic salamanders requiring cool, fast-flowing lotic systems (Fig. 1) Once found in tributaries throughout the Ohio and Wabash River watersheds Now restricted to a single river in southern Indiana (Fig. 2) 20 years of monitoring has revealed significant, ongoing declines in the abundance of hellbenders in the Blue River No evidence of successful recruitment during this time leading to an increasingly geriatric population All points recorded on Garmin Rino 86 and imported into ESRI ArcGIS 10.2 (Fig. 3) Distance between points calculated with R package “geosphere” Linear Home Range (LHR) Calculation Points snapped to line representing river midpoint Points connected and distance (m) of line measured (Fig. 3) Mean Convex Polygon (MCP) Home Range Calculation Minimum bounding geometry tool with convex hull geometry type Polygon area (m2) measured (Fig. 3) Movement Probability Variable Estimate SE P-value Intercept -1.840 0.197 <2e-16 Time Since Last Observation -0.184 0.048 0.0001 Time Since Release 0.338 0.034 Site Density -0.207 0.082 0.0119 Fall 0.218 0.090 0.0148 Predicted movement probability over time Distance Moved Variable Estimate SE P-value Intercept 2.94 0.106 <2e-16 Time Since Last Observation 0.115 0.038 0.0027 Site Density -0.154 0.070 0.0286 Fall 0.688 0.083 Status 0.698 0.187 0.0002 Predicted movement probability as a function of site density Home Range-LHR Movement and Management Variable Estimate SE P-value Intercept 5.1927 0.1359 <2e-16 Number of Observations 0.2055 0.1137 0.0707 Status 0.599 0.2412 0.0129 Movement tracked 3x weekly during field season (May – November) via radio telemetry Pre-management 2008-2009 21 resident adult hellbenders tracked at 8 sites Post-management 2011-2012 42 individuals tracked at 2 sites where translocations were undertaken to increase local densities Site 1 contained resident adult hellbenders (11) and translocated adult hellbenders (11) from isolated sites across the river Site 2 contained resident adult hellbenders (10) and translocated captive-reared juvenile hellbenders (10) Predicted movement distance for resident and translocated hellbenders Home Range-MCP Variable Estimate SE P-value Intercept 9.562 0.3901 <2e-16 Age -1.0266 0.4260 0.016 Predicted LHR and MCP home range sizes for statistically independent groups Figure 3. Location points, LHR and MCP for an individual hellbender in the study Figure 1. An eastern hellbender on the banks of the Blue River Figure 2. The location of the Blue River in southern Indiana Predicted movement distance as a function of site density Statistical Models Model Type Generalized Linear Mixed Model Generalized Linear Model Discussion Management Less movement (probability and distance) at higher site densities Temporal Initial period of higher movement probability decreases over time More movement (probability and distance) in the fall which is when breeding occurs Individual Translocated hellbenders move more resulting in larger home ranges Effect more pronounced in juvenile age classes Random Effects Animal ID Site ID Negative Binomial Binomial Research Question Error Distribution Are hellbender movement patterns or home range sizes in the Blue River impacted by management actions, temporal patterns, or individual hellbender characteristics? Response Movement Probability Movement Distance LHR Size MCP Size Covariates: Management Site Density (hellbenders/kilometer) Management (pre or post) Acknowledgements Covariates: Temporal Time Since Release Season (summer or fall) Financial support was provided by the Indiana Department of Natural Resources, Division of Fish and Wildlife, Wildlife Diversity Section, State Wildlife Improvement Grant T07R11 and the Department of Forestry and Natural Resources at Purdue University. Eastern Hellbenders were collected, handled, and processed following standard procedures approved by the Purdue Animal Care and Use Committee (PACUC; 08-025-11) and in accordance with Indiana Scientific Permit # 13-0087. Covariates: Individual Age (juvenile or adult) Status (translocated or resident) Sex (female or male) Covariates: Control Time Since Last Observation Number of Observations