How temperature influences displacements and corpse aggregation behaviors in the ant Messor sancta

Abstract

We studied the effects of temperature on movement and individual corpse aggregation behaviors (picking up or dropping a corpse) in the ant Messor sancta. Dispersion of ants in space was higher at 30 °C than at 16 °C. Concerning aggregation behaviors, we observed at both temperatures that the probability of picking up a corpse from a pile was negatively correlated with pile size, while the probability of dropping a corpse was positively correlated with pile size. The combined picking up and dropping behaviors represent a local amplifi cation of corpse aggregation that is stronger at 30 °C than at 16 °C. Overall, this study shows clearly that the transport of corpses by ants, as well as the amplifi cation process involved in corpse aggregation, is modulated by temperature. The implications of these results on the dynamics of ant cemetery formation (and other aggregation behaviors) are discussed. We propose that the modulation of a local amplifi cation process by an environmental factor could be a general mechanism involved in the coordination of ant activity to adapt the external and internal shape and organization of the nest to environmental conditions.

From individual to collective displacements in heterogeneous environments

“…Individual animal displacement in a homogeneous space can frequently be modelled as a correlated random walk (Bovet and Benhamou, 1988;Turchin, 1998;Challet et al, 2005). Such a random walk corresponds at the population level to a diffusive process with a diffusion coefficient that can be estimated from the animal's movement characteristics (Patlak, 1953;Challet et al, 2005) or from its net squared displacement (Einstein, 1905;Kareiva and Shigesada, 1983).…”

Thermoregulation strategies in ants in comparison to other social insects, with a focus on Formica rufa

“…Their rate of development is accelerated with high temperatures 1 , the movement rate speeds up 2 and the rate of food and oxygen consumption also increases 3 . Higher temperatures can be advantageous for colony fitness as it can increase reproduction rate though at the same time can be disadvantageous due to higher energy expenditure 4 .…”

Excavated substrate modulates growth instability during nest building in ants

“…Several studies have highlighted the effect of environment on such self-organized behaviours (Deneubourg et al 1989;Franks et al 1991;Bonabeau et al 1998;Nicolis & Deneubourg 1999;Detrain & Deneubourg 2002;Jeanson et al 2003;Challet et al 2005;Colasurdo et al 2007;Jost et al 2007;Dussutour et al 2008). The surrounding characteristics modify the collective pattern by triggering changes in individual responses or even by simply mediating the interaction between workers.…”