Diurnal Swimming Patterns of Loggerhead Turtles during their Breeding Period as Observed by Ultrasonic Telemetry

Abstract

The swimming behavior of the loggerhead turtles Caretta caretta was studied by ultrasonic telemetry. Three adult female loggerhead turtles, captured as they crawled onto Moto Beach Kochi, Japan, were equipped with 50 KHz ultrasonic depth transmitter and released. The swimming speed of the turtles was faster at night than in the day. The vertical movements of the turtles were irregular at night and in the morning, but the turtles usually swam near the sea surface in the afternoon. The movements of the turtles could be divided into six swimming patterns. © 1991, The Japanese Society of Fisheries Science. All rights reserved.