northern alligator lizard hsi model

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HABITAT SUITABILITY INDEX MODEL FOR THE NORTHERN ALLIGATOR LIZARD (ELGARIA COERULEA) John Tapley, Skyler Kernodle, Kelsi Potterf, and Corbin Williamson

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  1. 1. John Tapley, Skyler Kernodle, Kelsi Potterf, and Corbin Williamson
  2. 2. Habitat Use Information General Information Food/Water Interspersion Cover Type Habitat Suitability Index Geographic Area and Seasonality Model Description and Verification Level SI Graphs and Variable Definitions Equation Determination and Application
  3. 3. Prefers grassy, bushy, and rocky areas within forested areas (4). Includes clearcuts, stream sides, rocky outcrops and talus (6). Inhabit areas typically within 2 m of shrub cover (8).
  4. 4. Sit and Wait Forager (11). Crickets, mealworms, young small mammals, arachnids, other small lizards, snails, and other insects (9). Lingual transport and puncture crushing when feeding (3). Not dependent on water source; water obtained by food (9).
  5. 5. Low density populations (8, 11,12). When ideal habitats are scarce, individuals must move across the landscape to meet their requirements (2). Migration from hibernation dens to summer habitat (9). Dispersal patterns of young are largely unknown (8). Adults exhibit high site fidelity (8). Idaho populations occur on the periphery of the species range (4).
  6. 6. Rocky outcrops clearings associated with forest edge (8). These areas are abundant in food sources (4). Habitats utilized for thermoregulatory properties (8).
  7. 7. Appendix 1. Known global distribution of the northern alligator lizard (3). Appendix 2. Known populations and predicted distribution of the northern alligator lizard in Idaho (4). Most active from April to September Hibernation occurs from mid- September to March (8).
  8. 8. Verification Level: (S2) or Imperiled species in Idaho (4). Declines caused by habitat degradation such as (1). IUCN lists as a species of least concern across range (3). Model Description: Transition habitats may be utilized though summer habitat requirements appear to be consistent (6, 8, 9). Requirements adopted from observations by Rutherford and Gregory (8).
  9. 9. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 2 4 6 8 10 SuitabilityIndex Avg. Distance to Forest Edge (m) Measured from forest edge to proposed ideal habitat Defined by a vast reduction in tree density Permanent/continuous opening in canopy over habitat
  10. 10. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 20 40 60 80 100 SuitabilityIndex % Rock Cover Percent of ground covered by rock or talus