Integrating biotic factors into niche modeling: a case study with Rhipicephalus (Boophilus) microplus in the Americas

The cattle tick Rhipicephalus (Boophilus) microplus is known to transmit both anaplasmosis and babesiosis, two diseases that have important impacts on animal health. To delimit areas of climatic suitability where this species can spread and areas prone to infestation (with possible negative effects on cattle production), we explore the utility of tools from the field of distributional ecology. We first apply a statistical model to estimate the fundamental climatic niche of R. (B.) microplus, and then we propose a methodology by which to incorporate biotic factors into the model to approximate the species’ realized niche. Using a Bayesian approach, we combined information on climatic tolerance ranges previously obtained through physiological experiments with occurrence records of the tick to approximate its potential distribution. To approximate the realized niche of the species, we used occurrence data of different wild host species to identify regions holding appropriate biotic conditions for the presence of tick populations, making them prone to infestation and of economic importance. We compared our models against models fitted with maximum entropy approaches (MaxEnt). MaxEnt did not produce biologically realistic estimates of the species’ fundamental niche, and showed anomalies in the predicted geographic distribution. This study is the first to propose a method to include biotic factors in the niche modeling framework for this tick species. Our methodology can be used in ecological niche modeling studies of other species for which the biotic interactions, environmental conditions, and the life history of the focal species are documented. We suggest a new approach to incorporate biological interactions in ecological niche modeling. Physiological data together with geographical approaches lead to comprehensive predictions of species distributions. Our study offers insights into the complex ecology of ticks and underscores the need for ongoing monitoring.