Injuries in nesting females of Cape Verde loggerhead colony

Abstract

Natural threats in marine turtles are well known and have an important impact in the first stages of their life cycle. The International Union for Conservation of Nature (IUCN) classifies the loggerhead sea turtle (Caretta caretta) as an endangered species due to the important reduction of their population’s sizes worldwide. In this work, we pretend to analyze main injuries observed in Cape Verde loggerhead nesting females in order to identify main threats and impacts affecting this colony, just like possible temporal trends. There have been studied 11.090 loggerhead-nesting females localized during the nesting process, on the south-eastern beaches of Boa Vista Island (Cape Verde), from 2005 to 2015 nesting seasons. Data used for this study come from the database collected by Cabo Verde Natura 2000 NGO from 1998. Turtle injuries were classified into two main groups: “Carapace lesions” subdivided into, carapace fracture, shark attack, barnacle holes, small lesions and undetermined lesions. The second group include the flippers lesions, subdivided into front flipper and rear flipper lesions. The studying area comprises 20 Km of nesting beaches hosting the highest nest densities in the Archipelago and included in two Protected Areas (Reserva Natural das Tartarugas and Parque Natural do Norte). The area was divided into four zones for the analysis. The results indicate small variations in the frequencies of the lesions analysed along the years, between zones and in relation with the carapace length. Finally, the effect of flipper amputation in nesting success was analysed, identifying an important negative impact on the reproductive success of the colony.