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

<p><span><span>Leadership of animal group movements depends on social feedback, hence leader's signals and follower's responses should be attuned to each other. However, leader and follower roles are difficult to disentangle in species with high levels of coordination. To overcome this challenge, we investigated a simple case of movement coordination: termite pairs in which a female leads a male as they search for a nest site. To tease apart leader and follower roles, we created conspecific and heterospecific pairs of <i>Coptotermes gestroi</i> and <i>C. formosanus</i>, which share a pairing pheromone so that males follow females of either species. Conspecific pairs were stable for both species, even though <i>C. gestroi</i> females produce less pheromone than <i>C. formosanus</i>. Heterospecific pairs with <i>C. gestroi</i> males were also stable, but not those with <i>C. formosanus</i> males. We attributed this difference to the <i>C. gestroi</i> male's unique capacity to follow females that release small amounts of pheromone; <i>C. formosanus</i> males cannot follow or reject <i>C. gestroi</i> females as unsuitable. This conclusion was supported by an information-theoretic analysis that detected information flow from female to male in only stable tandems. Despite their following ability, <i>C. gestroi</i> males lost to <i>C. formosanus </i>males in competitions to follow <i>C. formosanus</i> females. Thus, partner selection has shaped the species-specific association of mating pairs. Our results demonstrate that a similar level of coordination can emerge from distinct sets of complementary sender-receiver interactions.</span></span></p>