What can we learn about the behaviour of red and grey squirrels from YouTube?
Citizen science has emerged as an important tool in biology, ecology, and conservation studies. In this paper, we examined YouTube (YT) videos featuring the behaviour of red (Sciurus vulgaris) and grey (Sciurus carolinensis) squirrels in Europe, in both urban and forest habitats. Our study shows that specific behaviours of these squirrels, such as aggression, grooming and calling, have frequently been recorded on YT videos. The present paper uses this open data for the first time to compare differences between the frequency of some types of behaviour in two habitats. Based on detrended correspondence analysis, we show a significant difference in sets of behaviours between two squirrel species. Our investigation show that YT can be a source for monitoring the behaviour of wild species, especially in urban habitats, thus affording insights into the species plasticity of urban individuals. YT, as part of citizen science, is a potential source of information in behavioural ecology.