Herpetology Notes

Herpetology Overview

• Course Information
  • Dr. Jason R. Bohenek, ENV 320B
  • Lecture MWF 11:00 - 11:50
  • Lab W 1:00 - 3:50pm
  • MS Teams: @Bohenek, Jason

Behavioral Ecology Chapter 8: Key Objectives

• Understand reasons for animal movement
• Comprehend herpetological communication
• Learn foraging strategies
• Grasp predator avoidance techniques

Local Distributions: Home Ranges

• Home Range Definition: Area an individual regularly occupies without defending from others
• Influenced by:
  • Species and sex
  • Body size
  • Population density
• Estimation Methods: Minimum polygons (convex hulls)

Home Range Characteristics

• 3D Space Use: Variations noted in aquatic and terrestrial environments
• Fossorial species: Tiny home ranges
• Migrations for breeding not included in home range estimates

Home Range Variations

• Microhabitat shapes affect home range shape
• Seasonal changes alter range sizes (e.g., male breeding ranges increase)

Territories

• Territory Definition: Defended area within home range
• Criteria: Fixed area, defended behaviors, exclusive use by resident
• Territorial behaviors: Aggressive displays, vocalizations, pheromones

Movement and Migration Patterns

• Most herps have limited lifetime movement
• Movement drivers: Breeding, foraging, environmental changes
• Diurnal vs nocturnal behavior varies by species

Dispersal and Orientation

• Dispersal: Undirected movement, usually by juveniles
• Homing: Ability to return to specific locations
• Orientation: Determining direction using environmental cues
• Methods: Chemical, visual, polarized light, magnetic orientation

Key Mechanisms of Homing

• Some salamanders can home several kilometers; turtles vary (some > 500 km)
• Evidence of using polarized light for navigation observed in certain species (e.g., Trachemys scripta)

Conclusion

• Understanding movement and territoriality in herps provides insights into their ecology and behavior.
• These factors are crucial for conservation efforts, especially considering habitat changes and migratory challenges.