No abstract

How do termite inquilines manage to cohabit termitaria along with the termite builder species? With this in mind, we analysed one of the several strategies that inquilines could use to circumvent conflicts with their hosts, namely, the use of distinct diets. We inspected overlapping patterns for the diets of several cohabiting Neotropical termite species, as inferred from carbon and nitrogen isotopic signatures for termite individuals. Cohabitant communities from distinct termitaria presented overlapping diet spaces, indicating that they exploited similar diets at the regional scale. When such communities were split into their components, full diet segregation could be observed between builders and inquilines, at regional (environment-wide) and local (termitarium) scales. Additionally, diet segregation among inquilines themselves was also observed in the vast majority of inspected termitaria. Inquiline species distribution among termitaria was not random. Environmental-wide diet similarity, coupled with local diet segregation and deterministic inquiline distribution, could denounce interactions for feeding resources. However, inquilines and builders not sharing the same termitarium, and thus not subject to potential conflicts, still exhibited distinct diets. Moreover, the areas of the builder’s diet space and that of its inquilines did not correlate negatively. Accordingly, the diet areas of builders which hosted inquilines were in average as large as the areas of builders hosting no inquilines. Such results indicate the possibility that dietary partitioning by these cohabiting termites was not majorly driven by current interactive constraints. Rather, it seems to be a result of traits previously fixed in the evolutionary past of cohabitants.

Animal movements have been related to optimal foraging strategies where self-similar trajectories are central. Most of the experimental studies done so far have focused mainly on fitting statistical models to data in order to test for movement patterns described by power-laws. Here we show by analyzing over half a million movement displacements that isolated termite workers actually exhibit a range of very interesting dynamical properties –including Lévy flights– in their exploratory behaviour. Going beyond the current trend of statistical model fitting alone, our study analyses anomalous diffusion and structure functions to estimate values of the scaling exponents describing displacement statistics. We evince the fractal nature of the movement patterns and show how the scaling exponents describing termite space exploration intriguingly comply with mathematical relations found in the physics of transport phenomena. By doing this, we rescue a rich variety of physical and biological phenomenology that can be potentially important and meaningful for the study of complex animal behavior and, in particular, for the study of how patterns of exploratory behaviour of individual social insects may impact not only their feeding demands but also nestmate encounter patterns and, hence, their dynamics at the social scale.

Inter-specific symbiotic links are often reinforced by morphological, physiological, or behavioural trait modification undergone by the associated species. In some cases, such as in physogastric termitophile staphylinids, such modifications do facilitate the social interaction. Here we inspect chemical traits of the physogastric staphylinid Corotoca melantho (Insecta: Coleoptera) and its termite host Constrictotermes cyphergaster (Insecta: Blattodea: Isoptera), aiming to verify whether staphylinids resemble their host. First, we compared CHC profiles of hosts and guests within and among termitaria, to gather evidence on the origin of such profiles in guests. Then, we examined nitrogen and carbon isotopic signatures of these cohabitants to inspect whether chemical disguise is achieved by predation of host workers by staphylinids. Beetles presented CHC more similar to the CHC of their cohabiting termites than to (i) their conspecifics and (ii) termites from another nest, thereby favouring the hypothesis on CHC acquisition by guests. Isotopic signatures revealed that such similarities could not be majorly determined by share nutrition between these cohabitants. In general, our results evidenced that chemical disguise in termitophiles may function as a strategy for social integration in morphological mimics.