HORIZONTAL AND VERTICAL MOVEMENT BEHAVIOUR OF THE LEATHERBACK TURTLE Dermochelys coriacea.

Abstract

The general biology of the leatherback turtle (Dermochelys coriacea) still remains poorly understood, mainly because of its life-history characteristics. D. coriacea is a highly pelagic cosmopolitan species that spends most of its life in the open sea, and is able to perform transoceanic migrations from reproductive to foraging zones and back. Over their long travels throughout the sea, the leatherback turtle moves both horizontally (e.g., migrations) and vertically (i.e. dives) in response to different factors, like searching for suitable habitats for growth, feeding and reproduction. The present article is a  comprehensive review of the current knowledge about the horizontal and vertical behavioral movements performed by D. coriacea. An analysis of how these behaviors are influenced by different factors governing the ecology of this species is presented. Some studies indicate that oceanographic features are the key factors determining the movement patterns observed for D. coriacea, mainly during their geographic migrations and residence in feeding zones. In short, the leatherback turtle employs different navigation and dispersion strategies while in each different oceanic zone. On certain occasions, individuals may disperse in different directions while on other occasions they may follow a roughly uniform path across the sea. Movement trends during the nesting period vary between different oceanic zones depending on local topography and on the behavioral strategy adopted by the nesting females with respect to how to invest energy during the reproductive season (e.g., actively searching for prey versus limiting activity to reduce metabolic rate).