Consequences of the exploitation of tracajás (Podocnemis unifilis) in their role as seed dispersers in flooded forests

• Grant number: 24/13276-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Raul Costa Pereira
• Grantee: Leticia Alexandre
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Turtles have historically been targets of human exploitation. Like many other animal groups, humans exploit turtles non-randomly, prioritizing the largest and longest-lived individuals within natural populations. A clear example of this scenario is the hunting of the river turtle, Podocnemis unifilis, an Amazonian species classified as vulnerable by the International Union for Conservation of Nature (IUCN). River turtles are omnivores, but their diet consists mainly of plant matter. During the rainy season, this species consumes a large quantity and diversity of fruits and seeds, acting as an important seed disperser in flooded Amazonian forests. Larger river turtles, due to their wider gape sizes, can consume fruits and disperse large seeds, an ecosystem service threatened in landscapes under human influence. In this sense, size-selective exploitation of this species is expected to impact its role as seed dispersers, as larger fruits and seeds might face dispersal limitation. In this project, we will investigate how river turtles' body size variation across exploited and non-exploited populations affects their role as frugivores and seed dispersers. Our results will contribute to a better understanding of how overexploitation of frugivores impairs the ecosystem service of large seed dispersal in tropical forests.