Time-concentrated sampling: a simple strategy for information gain at a novel, depleted patch

Abstract

When an animal has found and consumed food at a new location, information about whether and when food will be present again could improve future foraging efficiency. A series of rapid returns followed by less frequent visits and finally abandonment of the patch could provide such information. By analogy with area-concentrated (area-restricted) search, we call this hypothesized pattern “time-concentrated sampling”. We tested whether eastern chipmunks ( Tamias striatus (L., 1758)) would show time-concentrated sampling in the field and whether the pattern of visits would be affected by patch value. We used peanuts to induce animals to discover a small patch of sunflower seeds. After depleting the patch, returning to find it empty, and leaving without food, 36 of 40 animals returned on sampling visits. Sampling rate was initially high and declined over 4 h. The number of peanuts and number of visits where seeds were obtained positively predicted sampling rate, but the volume of sunflower seeds presented and the distance to the burrow did not. We conclude that chipmunks exhibit flexible time-concentrated sampling.