Unusual behaviour of an immature loggerhead turtle released in the Alboran Sea

J J Bellido,J J Castillo,R Real,J J Martín,J L Mons,J C Báez

doi:10.32800/abc.2010.33.0015

Abstract

A juvenile loggerhead turtle with buoyancy problems was captured in the Alboran Sea (Mediterranean Sea, south of Spain) and released 14 months later after healing. Six days after the release, the turtle was seen swimming 42 km from the point of release, displaying unusual behaviour. We re-captured and released it again, 95 nautical miles offshore, near the Alboran Island. Ten days later the turtle arrived at the beach close to where it had been maintained in captivity. We discuss these findings in the context of behavioural alteration and habituation in released sea turtles. Capture-mark-recapture studies of sea turtles should be approached with caution as manipulated animals may modify their usual behaviour.

Highlights

In animal behaviour philopatry has been defined as a tendency to remain in, or return to, an individual’s birthplace (Parker, 2003)
We present the unusual behaviour of an imma ture loggerhead turtle released in the Alboran Sea, and examine the possible consequences of such modifications in studies of marine migratory species
The Alboran Sea connects the Western Mediterranean Sea with the Atlantic Ocean. It is an outstanding area for megafauna in the North Atlantic–Mediterranean region, providing an important corridor for migratory marine turtles (e.g. Camiñas, 1997).The loggerhead turtle Caretta caretta is the most abundant sea turtle (Bellido et al, 2010) in this region but little is known about its use of the Alboran coast

Summary

Introduction

In animal behaviour philopatry has been defined as a tendency to remain in, or return to, an individual’s birthplace (Parker, 2003). It is well known that sea turtles have a strong sense of orientation and return to their natal beaches after many years Swingle et al (1994), found that released turtles exhibited alterations in behaviour, and Addison & Nelson (2000) reported another case of habituation in a loggerhead sea turtle from Florida (Atlantic USA).

Results

Conclusion