Coordination of movement via complementary interactions of leaders and followers in termite mating pairs

Abstract

In collective animal motion, coordination is often achieved by feedback between leaders and followers. For stable coordination, a leader's signals and a follower's responses are hypothesized to be attuned to each other. However, their roles are difficult to disentangle in species with highly coordinated movements, hiding potential diversity of behavioural mechanisms for collective behaviour. Here, we show that two Coptotermes termite species achieve a similar level of coordination via distinct sets of complementary leader–follower interactions. Even though C. gestroi females produce less pheromone than C. formosanus , tandem runs of both species were stable. Heterospecific pairs with C. gestroi males were also stable, but not those with C. formosanus males. We attributed this to the males' adaptation to the conspecific females; C. gestroi males have a unique capacity to follow females with small amounts of pheromone, while C. formosanus males reject C. gestroi females as unsuitable but are competitive over females with large amounts of pheromone. An information-theoretic analysis supported this conclusion by detecting information flow from female to male only in stable tandems. Our study highlights cryptic interspecific variation in movement coordination, a source of novelty for the evolution of social interactions.

Cryptic functional diversity in ant tandem runs

“…Note that Diacamma leaders modify their behavior to facilitate coordination even though the interaction is unidirectional. For example, the leader’s moving speed during tandem runs is slower than when the leader is alone (Kaur et al, 2017), contrasting with the termite leaders that show consistent movement speed even with male followers (Mizumoto et al, 2021). As a result, Diacamma tandem runs are highly stable with few interruptions (Fig.…”

“…Most tracking software recognizes a tandem pair as a single individual and fails to distinguish partners from each other. The coordinates of tandem partners can be well extracted using UMATracker software (Yamanaka and Takeuchi, 2018), as evidenced by previous studies (Mizumoto et al, 2022(Mizumoto et al, , 2021(Mizumoto et al, , 2020 . CC-BY-NC-ND 4.0 International license made available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.…”

“…Most tracking software recognizes a tandem pair as a single individual and fails to distinguish partners from each other. The coordinates of tandem partners can be well extracted using UMATracker software (Yamanaka and Takeuchi, 2018), as evidenced by previous studies (Mizumoto et al, 2022(Mizumoto et al, , 2021(Mizumoto et al, , 2020Mizumoto and 10 Dobata, 2019;Valentini et al, 2020b). One of the prerequisites of the UMATracker is a fixed number of individuals in a video frame.…”

Ancestral sex-role plasticity facilitates the evolution of same-sex sexual behavior

“…Our first analysis tested whether behavior differs in samesex versus heterosexual tandems. To compare the time engaged in tandem runs across pairs, we automatically identified whether a pair was performing tandem runs for every video frame, combining methods described in previous studies (18,56,57). During observations, pairs were determined to be in one of three states: 1) tandem running, 2) interacting but not tandem running, and 3) searching (individuals in the pair are physically separated).…”

Ancestral sex-role plasticity facilitates the evolution of same-sex sexual behaviour

“…Our first analysis tested whether behaviour differs in same-sex versus heterosexual tandems. To compare the time engaged in tandem runs across pairs, we automatically identified whether a pair was performing tandem runs for every video frame, combining methods described in previous studies [14,43,44]. During observations, pairs were determined to be in one of three states: (i) tandem running, (ii) interacting but not tandem running, and (iii) searching (individuals in the pair are physically separated).…”