Need for speed? It is not necessary to be always the fastest–a case study of two thermophilous ant species

When the decisions about the movement are made and the animal should
adjust the trajectory and movement speed to maximise the efficiency in
reaching its goal. The most important environmental factor, which
influence the movement in case of ectothermic ants, is temperature. In the
current experiment, we compared how species with different thermal
adaptations responded to foraging in the thermally challenging conditions.
To be more specific, how the external temperature influences the inbound
time and path (straightness) of ants' movement when they return to
the nest with prey. Generally, workers’ inbound time was linked with the
mean speed of foraging ants in case of both species–faster workers return
earlier to the nest. The straightness of workers’ movements–the path they
took to the nest–was not linked with sand temperature, nor with the speed
of workers in case of C. velox. On the contrary, in case of A. senilis,
the straightness of workers’ movements was linked with mean speed of ants.
The faster workers choose the most straight path to the nest entrance. The
difference in behavioural response of both species may derive from the
physiological differences between species. C. velox, as a more
physiologically temperature resistant and generally faster seem to have a
broader bandwidth of behaviours concerning the choice inbound trajectory
with no need to narrow it when the temperature rises e.g. increase the
movement straightness. Each of the species tries to take the advantage
based on their stronger properties, C. velox on its higher speed and A.
senilis on higher straightness and also possibility to recruit nestmates.