Mean swimming speed of diamondback terrapins in response to playback recordings of approaching boats.

Small (400 to 600 g) and large (1000 to 1200 g) terrapins were exposed to playback recordings of approaching recreational boats during sound trials and no sound during control trials. Swimming speed was measured for each terrapin every 10 m through the 60 m experimental canal and standardized by body length. One of four playback recordings was started when each terrapin was 10 m from the underwater speaker.