Does the photoluminescence of rat fur influence interactions in the field?

Abstract

While the photoluminescence of mammal fur is widespread, any potential function based on its optical properties remains speculative. Using paired photoluminescent and non-photoluminescent real-fur rat models in a field experiment, we aimed to test whether nocturnal vertebrates reacted differently to blueish-white photoluminescent fur than to non-photoluminescent fur. Remote cameras were set out in three different habitats (farmland, rainforest and woodland) in the Wet Tropics of Far North Queensland, Australia, over three full moon and three new moon phases. We recorded what species interacted with the models and counted the number of interactions with each model to calculate pair-wise differences of interactions with photoluminescent and non-photoluminescent models. No animal group (marsupial, placental mammal or avian) showed a preference for either model, on either new or full moon, suggesting that they either cannot detect a difference, or that preference is not based on photoluminescent properties. These findings do not support a hypothesis of selective pressure from nocturnal vertebrates acting on the trait of blueish-white photoluminescence in mammal fur.