Spatio-temporal learning by the ant Ectatomma ruidum

We tested, under field and laboratory conditions, whether the neotropical a nt Ectatomma ruidum Roger can learn several associations between temporal a nd spatial changes in the daily pattern of food availability. Honey was shu ffled between two or three feeding sites following a fixed daily schedule. Foragers learnt to associate particular sites with the specific times at wh ich food was available, individually marked ants being observed on the corr ect sites at the correct times, Some ants anticipated the time of food deli very by approximately 30 min, and it was not necessary for them to be rewar ded at the first stage of the sequence of food collection to continue their search for honey according to the correct schedule of reward. Ants also fo llowed the same schedule when no honey was supplied at each stage of the se quence, and they stayed at the expected unrewarded site for a period equiva lent to the reward period of the corresponding training phase, indicating t hat they had learnt when and for how long the food was available. Thus, ant s rely on their spatio-temporal memory rather than on local cues coming fro m the honey source to guide them.