Exploring exploration: A multidimensional analysis of exploration across standardised and semi-natural contexts in rats

Louisa Bierbaum, Carlina Feldmann, Sina Mews, Regina Rumpel, Sylvia Kaiser, S. Helene Richter

Exploration is a major personality trait in animals that reflects individual differences in gathering information about environmental features relevant to survival and reproduction. Yet, exploration is commonly assessed using brief standardised tests, which provide a convenient but artificial experimental setting. Whether such measures reflect how individuals explore complex and changing environments under more natural conditions remains unclear. Here, we aimed to provide a multidimensional assessment of exploration across a standardised and a semi-natural context in female laboratory rats (Rattus norvegicus). We combined three repeated Open Field tests with six weeks of continuous RFID tracking in a semi-natural environment. We additionally introduced foraging and simulated risk events to examine exploration under more dynamic environmental conditions. On the group level, distance travelled in the Open Field declined after the first exposure. Movement and space use in the semi-natural environment likewise varied across event-free nights but without following a uniform temporal pattern. Foraging and risk events both increased movement but affected visits to the manipulated cages differently. Rats entered food-reward cages more frequently and remained there longer, whereas risk events were characterised by more frequent but shorter visits to the manipulated cages. Individual differences in exploration were repeatable within both contexts, although their strength depended on the behavioural measure. Despite this within-context consistency, Open Field distance was not associated with initial exploration or longer-term movement and space use in the semi-natural environment while associations with foraging and risk events were weak and restricted to specific events. Overall, our findings show that exploration comprises partly distinct components captured by different behavioural measures and influenced by environmental context. Standardised tests and semi-natural observations should therefore be considered complementary rather than interchangeable, emphasising the need for multidimensional assessments when characterising exploration as a personality trait.