Meeting Abstract
Underwater activity increases the metabolic requirements of aquatic animals therefore air-breathing vertebrates adjust diving and surfacing durations to match their respiratory needs. Under lab conditions, CO2 build-up triggers turtles to breathe at the surface but they can hold their breath for hours during deep dives or months during winter. Unfortunately, studying free-ranging underwater behavior of shy freshwater turtles has been nearly impossible in densely-vegetated wetlands. To address this, we quantified the behavioral time budgets of adult snapping turtles (Chelydra serpentina) in Connecticut using an animal-borne video recorder (CRITTERCAM) with automatic detachment (n=12 turtles; 56h of video; 880 dives). Individuals displayed tremendous variation (range 5.3 to 60.8 surfacing events/hour) and on average spent 20% (±19% s.d.) of their time surfacing. Turtles at rest underwater remained submerged for long durations and at the surface continued resting in long bouts. As metabolically expected, active underwater behaviors like walking and swimming had shorter dive durations than resting behavior. Surprisingly, underwater activity limited surfacing duration as turtles re-submerged relatively quickly after feeding and locomotor behaviors (after accounting for the positive effect of previous dive duration). This remote imaging perspective shows how underwater behavior influences diving and surfacing patterns in wild snapping turtles and how remote imaging helps understand vagile yet cryptic creatures.
