Nonaggressive behavior: A strategy employed by an obligate nest invader to avoid conflict with its host species

Abstract

In addition to its builders, termite nests are known to house a variety of secondary opportunistic termite species so‐called inquilines, but little is known about the mechanisms governing the maintenance of these symbioses. In a single nest, host and inquiline colonies are likely to engage in conflict due to nestmate discrimination, and an intriguing question is how both species cope with each other in the long term. Evasive behaviour has been suggested as one of the mechanisms reducing the frequency of host‐inquiline encounters, yet, the confinement imposed by the nests' physical boundaries suggests that cohabiting species would eventually come across each other. Under these circumstances, it is plausible that inquilines would be required to behave accordingly to secure their housing. Here, we show that once inevitably exposed to hosts individuals, inquilines exhibit nonthreatening behaviours, displaying hence a less threatening profile and preventing conflict escalation with their hosts. By exploring the behavioural dynamics of the encounter between both cohabitants, we find empirical evidence for a lack of aggressiveness by inquilines towards their hosts. Such a nonaggressive behaviour, somewhat uncommon among termites, is characterised by evasive manoeuvres that include reversing direction, bypassing and a defensive mechanism using defecation to repel the host. The behavioural adaptations we describe may play an important role in the stability of cohabitations between host and inquiline termite species: by preventing conflict escalation, inquilines may improve considerably their chances of establishing a stable cohabitation with their hosts.

The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas

“…Moreover, ecosystem engineers can modify habitats and provide novel resources that may be exploited by other non-native species, increasing their establishment success [25]. These complex facilitative interactions could be considered as inquilinism, in which some species (nest inquilines or tenants) use nests of other species and they can show parasitic, commensalistic, and mutualistic interactions with their hosts [26,27]. However, to our knowledge, this kind of inquilinism has not been considered in birds, although similar interactions from other nest builder birds have been recorded [28][29][30].…”

First evidence of wasp brood development inside active nests of a termite with the description of a previously unknown potter wasp species

“…Such a test would be particularly useful to confirm whether M. termitophila larvae have evolved chemicals to deter the termites and so avoid being detected inside the nest. In this same system ( C. cyphergaster ), host deterrence has been previously hypothesized based on the observation of inquiline termites ( I. microcerus ) that employ fecal pellets in response to the host termite's aggression (Hugo et al., 2020). We emphasize that none of the wasp brood cells we found (active or not) contained remnants of prey material.…”

“…Constrictotermes cyphergaster (Silvestri, 1901) is a Neotropical termite species that builds typical arboreal nests (Krishna et al., 2013; Vasconcellos et al., 2007) and is widespread throughout South America (Mathews, 1977). With nocturnal foraging habits and diet mostly based on lichens (Barbosa‐Silva et al., 2019) and tree bark (Moura et al., 2006), the species has drawn some attention due to its close association with nest invaders, such as Inquilinitermes microcerus (Silvestri, 1901) and Inquilinitermes fur (Silvestri, 1901) (for examples of studies, see Cristaldo et al., 2012, 2014, 2015, 2016; Cruz et al., 2018; Cunha et al., 2003; DeSouza et al., 2016; Florencio et al., 2013; Hugo et al., 2020; Rodrigues et al., 2018; Santos, 2016). Because of their limited constructive abilities (Emerson, 1938), these invader termite species are known to rely exclusively on nests of C. cyphergaster to establish their colonies, being not found anywhere else to date and, therefore, classified as “obligatory inquilines” (Mathews, 1977).…”

“…The species is also characterized by a reduced number of termite soldiers (Cunha et al., 2003) and an uncommon lack of aggressiveness toward its host termites. In fact, this inquiline species has been reported to adopt evasive behaviors when receiving attacks and make use of fecal pellets to disrupt the host's aggression (Hugo et al., 2020). This nonthreatening behavior contrasts with the typical aggression seen among termite species (Shelton & Grace, 1996).…”

“…Constrictotermes cyphergaster (Silvestri, 1901) is a Neotropical termite species that builds typical arboreal nests (Krishna et al, 2013;Vasconcellos et al, 2007) and is widespread throughout South America (Mathews, 1977). With nocturnal foraging habits and diet mostly based on lichens (Barbosa-Silva et al, 2019) and tree bark (Moura et al, 2006), the species has drawn some attention due to its close association with nest invaders, such as Inquilinitermes microcerus (Silvestri, 1901) and Inquilinitermes fur (Silvestri, 1901) (for examples of studies, see Cristaldo et al, 2012Cristaldo et al, , 2014Cristaldo et al, , 2015Cristaldo et al, , 2016Cruz et al, 2018;Cunha et al, 2003;DeSouza et al, 2016;Florencio et al, 2013;Hugo et al, 2020;Rodrigues et al, 2018;Santos, 2016).…”