Hosts, parasites and their interactions respond to different climatic variables

Abstract Aim Although there is a vast body of literature on the causes of variation in species composition in ecological communities, less effort has been invested in understanding how interactions between these species vary. Given that interactions are crucial to the structure and functioning of ecological communities, we need to develop a better understanding of their spatial distribution. Here, we investigate whether species interactions vary more in response to different climate variables than do individual species. Location Eurasia. Time period 2000s. Major taxa Animalia. Methods We used a measure of local contribution to β‐diversity to evaluate the compositional uniqueness of 51 host–parasite communities of rodents and their ectoparasitic fleas across Eurasia, using publicly available data. We measured uniqueness based on the species composition and based on potential and realized biotic interactions (here, host–parasite interactions). Results We show that species interactions vary more, across space, than do species. In particular, we show that species interactions respond to some climatic variables that have no effect on species distributions or dissimilarity. Main conclusions Species interactions capture some degree of variation that is not apparent when looking at species occurrences only. In this system, this appeared as hosts and parasites interacting in different ways as a response to different environmental factors, especially the temperature and dryness. We discuss the implications of this finding for the amount of information that should be considered when measuring community dissimilarity.