Intraguild predators can have behavioral mechanisms to maximize foraging and/or avoid predation. However, there is a lack of information about the influence of such prey-predator interactions on the daily activity of the species involved. Therefore, we investigated the daily activity of two intraguild predators, Tityus pusillus Pocock, 1893 and Ananteris mauryi Lourenço, 1982, in the presence and absence of each other. Animals were observed in three experimental conditions, containing individuals of T. pusillus (control 1), A. mauryi (control 2), and both species (treatment). In addition, we evaluated the correlation between the number of active individuals with air temperature and humidity. Our results showed that T. pusillus and A. mauryi have similar daily activity between 18:00 and 05:00 h. However, T. pusillus was more active and shifted from a sit-and-wait hunting mode to actively hunting when in the presence of A. mauryi. In contrast, under predation risk, A. mauryi did not change its level of activity but became more vigilant by reducing the frequency of rest, hydration, and mating attempts. Activity of A. mauryi was positively correlated with air humidity whereas activity of T. pusillus was negatively correlated. This work highlights the influence of intraguild predators in the behavioral decisions during daily activities of each other, indicating adaptive behaviors in both prey and predator.
