Effects of Ecological and Geographical Barriers on Homing in Three-Toed Turtles, Terrapene Carolina Triunguis

Roy L. King

Date of Graduation

Summer 2005

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Don Moll

Abstract

The present study examined the effects of barriers on the homing behavior of three-toe box turtles. Box turtles were presented with four different types of barriers: a heavily vegetated fence line, an area of no cover (mowed hayfield), a laboratory stream and a magnetic anomaly. Turtles were tested against the fence line and hayfield barriers in the field and against a stream and a magnetic anomaly in the laboratory. Areas of no cover represent a significant restriction to turtle travel as well as a threat due to predation and environmental exposure. Turtles attempting to cross streams with high water flow velocities (≥24.9 cm/s) risk death by drowning. Short to moderate lengths of captivity did not impact homing ability. Although box turtles may rarely encounter natural magnetic anomalies, such phenomena can significantly interfere with this species’ ability to use the earths’ magnetic field to determine direction. Turtles exhibited an ability to home. However, high amounts of precipitation can significantly diminish box turtle homing activity. Presumably, this is a result of increased cloud cover that obstructs the sun, a possible navigational cue. Thread-trailing techniques were employed in this study and were compared to radio-telemetry techniques. Thread-trailing allows for a more precise picture of each box turtle movements compared to radio-telemetry. The current study illustrates the event to which certain ecological and geographical barriers can impede three-toed box turtle travel and allows comparisons with travels characteristics of other small animal species.

Keywords

Terrapene, homing, behavior, barrier, ecology

Subject Categories

Biology

Copyright

© Roy L. King

Citation-only

Dissertation/Thesis

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