Anyone studying for an exam knows that learning and memory cost energy. If energy is limited, cognitive functions can be impaired or traded off. Writing in Biology Letters, Jaumann et al. used honeybees (Apis mellifera) to assess whether changes in resource allocation at the group level might relieve such effects in group-living animals (S. Jaumann, R. Scudelari & D. Naug Biol. Lett. http://dx.doi.org/10.1098/rsbl.2013.0149; 2013).

Credit: VISUALS UNLIMITED/NATUREPL.COM

They find that learning imposes an energetic cost on individual honeybees from a colony, and that — just as in solitary animals — learning and retention suffer during starvation or following an immunological challenge.

A worldwide trend of colony collapse resulting from bee disappearance is worrying scientists. The authors suggest that diseases, pesticide exposure or habitat changes may impose energetic stresses, particularly on foraging bees, that impair their ability to find their way home.