Nutritional constraints on ant colony foundation

Ecological systems are inherently complex. A long-standing challenge in ecology has been to identify general principles that bridge hierarchical phenomena from the individual to the ecosystem. Ecological stoichiometry (ES), the study of the balance of elements and energy in ecological systems, has emerged as a tool for generating these principles. Here we use ES to test linkages between biogeochemistry, organismal performance, and functional traits in “claustral” founding ant queens. Claustral founding queens, which rear their first brood entirely from stored reserves, should face a tradeoff between starvation resistance and specific growth rate because allocation of storage space to fat (high carbon:nitrogen (C:N) and carbon:phosphorus (C:P) ratios) for maintenance metabolism reduces space available for RNA (low C:P) and protein (low C:N) needed for rapid growth. Using claustral founding ant queens collected around the Southwestern Research Station in Portal, Arizona, we tested whether: 1) specific growth rate during colony founding increases with [P] and [RNA] in foundresses, 2) starvation resistance during colony founding increases with [storage lipid] in foundresses, and 3) there is a tradeoff between specific growth rate and starvation resistance that is manifested in a negative association between [RNA] and [storage lipid].  To test these hypotheses, we measured head width, dry mass, whole body content of P, C, N, lipids, and RNA content, as well as specific growth rate at ambient temperature for foundresses, brood, and workers. We predict that tradeoffs between functional traits in claustral founding queens will generally be manifested in foundress elemental composition.  Overall, the closed economy of founding queens is an ideal system for testing relationships between stoichiometry, biochemistry, and functional performance.