The Project
EvOCRO investigates how learning and cognitive flexibility develop across the lifespan of crocodiles and how individual differences shape these abilities, using Morelet’s crocodile as a model system.
Why crocodiles?
Crocodiles are long-lived predators equipped with highly developed sensory systems and living in complex and dynamic environments. However, their cognition has been explored far less than that of birds or mammals. Yet, crocodiles occupy a key evolutionary position: they belong to the archosaurs and diverged from birds (and dinosaurs) more than 250 million years ago, making them essential to understanding how cognition evolved within this evolutionary lineage. Studying their behavior therefore fills an important gap in comparative research and challenges the idea that only "classically complex" species are suitable models for studying animal cognition.
Research objectives
Studying crocodilian cognition helps bridge an important evolutionary gap and informs conservation efforts, environmental adaptability, enrichment practices and welfare guidelines. The project addresses three main objectives:
- RO1 – Ontogeny of learning: how learning abilities change from hatchlings to juveniles.
- RO2 – Individual differences: how sex and personality traits such as exploration or shyness affect learning performance.
- RO3 – Cognitive flexibility: whether crocodiles adapt when reward contingencies are reversed (reversal learning).
Approach and work packages
EvOCRO integrates behavioural ecology, comparative psychology, and evolutionary biology within an international collaborative network. The project leverages the unique opportunity to work with populations of Crocodylus moreletii raised in semi-natural conditions, which offer an ideal balance between experimental control and ecological realism. Here, we will observe the animals, test their cognitive abilities, and compare individuals of different ages, sexes, and personalities.
WP1 – Ontogeny of learning
WP1 tests how learning develops from hatching to the juvenile stage using positive reinforcement, two-choice discrimination tasks and reversal learning to quantify age-related cognitive changes.
WP2 – Individual differences
WP2 assesses sex and personality traits (e.g., boldness, exploration, response to novelty) and links them to the learning data generated in WP1 to understand how stable behavioural tendencies influence cognition.
WP3 – Cognitive flexibility
WP3 expands the learning tasks by repeatedly reversing stimulus–reward associations. This allows the project to quantify flexibility and measure how quickly individuals adjust to new rules.
WP4 & WP5 – Training, management and communication
WP4 focuses on scientific training, open science practices and career development. WP5 covers dissemination, publications, outreach activities and public engagement through media, workshops and events.
Impact
EvOCRO will expand scientific understanding of reptile cognition, provide novel longitudinal datasets and contribute to comparative evolutionary research beyond classical model species.
The findings will support conservation, welfare and management strategies in farms, zoos and protected areas, and will contribute to several UN Sustainable Development Goals through research, education and public engagement.