Staged-structured Lefkovitch matrix population modeling of turtle / Muhammad Rashiedy Mahadzir, Noorzahirah Rozali and Nurul Ramlah Muzani

This research is mainly focused on two types of turtles discovered in the islands of Sabah, Malaysia: Green Turtles and Hawksbill Turtles. Selingan Island (PSL), Bakkungan Island (PBK), and Gulasaan Island (PGL) had been chosen as the three islands. At this time, these two species of turtles were threatened with extinction. In light of this circumstance, research was conducted to simulate the turtle population on these three islands. The stage-structure of the Green Turtle and Hawksbill Turtle was interpreted using the Lefkovitch matrix model and the Leslie matrix model, which include potential rates associated with the turtle’s life cycle. Consequently, the future population size of turtles can be determined using the Lefkovitch matrix model and the Leslie matrix model. The highest future population for both of the turtles are in 2025 since the turtles have the highest number of forecasting eggs in the future. It can be related to determining how to maintain the turtle habitat in order to prevent the extinction of other turtles in the future, based on the future population results of turtles. The turtle habitat is threatened but still can be threatened in the future. The two matrix models are also used to predict the fecundity, growth rates, and survival rates of turtles and to identify the most vulnerable life stage that will require future protection. Based on the result, the prediction of the fecundity, growth rates, and survival rates for both of the turtles has been determined and the highest value is in 2025. The most vulnerable life stage of the turtles is in the class of eggs since the value of the annual survivorship is at the lowest. This study’s findings were discussed in order to compare the life stages of both types of turtles and the turtle populations on the three islands. Thus, all the objectives in this research have been achieved by calculating the number of population turtles in the future using the Lefkovitch and Leslie matrix model.