HABITAT SUITABILITY INDEX MODEL FOR THE NORTHERN ALLIGATOR LIZARD (ELGARIA COERULEA) John Tapley, Skyler Kernodle, Kelsi Potterf, and Corbin Williamson
1. John Tapley, Skyler Kernodle, Kelsi Potterf, and Corbin
Williamson
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. 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. 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. 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. Rocky outcrops clearings associated with forest edge (8).
These areas are abundant in food sources (4). Habitats utilized for
thermoregulatory properties (8).
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. 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. 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. 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