title: Resistance to nutritional stress in ants: when being fat is advantageous.
abstract: In ants, nutrient acquisition for the whole colony relies on a minority of workers, the foragers, which are often old and lean. Some studies have shown that the link between age, physiology and foraging activity is more flexible than once thought, especially in response to colony or environmental perturbations. This great plasticity offers the intriguing possibility to disentangle the effect of age, behaviour and physiology on the ants' abilities to cope with nutritional stresses. In this paper, we first looked at the capacity of groups of foragers and inner-nest workers to resist starvation and macronutrient imbalance. Second, we investigated whether behavioural task reversion modified the tolerance to nutritional stresses and by extension, changed mortality rate. We found that inner-nest workers live longer than foragers under nutritional stresses but not under optimal conditions. The reversion from foraging to inner-nest activities is followed by an increase in fat content and longevity. Finally, we demonstrated that changes in fat content associated with behavioural transition are highly flexible and strongly correlated to tolerance of nutritional stress. Our results have considerable implications for our understanding of the population dynamics of social insects under adverse nutritional conditions.
authors.affiliation: Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse 31062, France audrey.dussutour@univ-tlse3.fr.
authors.forename: Audrey
authors.initials: A
authors.lastname: Dussutour
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia 5005, Australia.
authors.forename: Laure-Anne
authors.initials: LA
authors.lastname: Poissonnier
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia 5005, Australia.
authors.forename: Camille
authors.initials: C
authors.lastname: Buhl
authors.affiliation: School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Simpson
mesh_terms: D000273:Adipose Tissue; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001000:Ants / Q000502:physiology*; D001070:Appetitive Behavior; D005508:Food Deprivation / Q000502:physiology; D009425:Nesting Behavior; D012919:Social Behavior
keywords: Ants; Fat; Flexibility; Lifespan; Nutrition