INFORMATION FOR PATCH ASSESSMENT - A FIELD INVESTIGATION WITH BLACK-CHINNED HUMMINGBIRDS

I examined the kinds of information black-chinned hummingbirds (Archilochus alexandri) used when exploiting artificial resource patches in the field. I determined whether birds (1) only used current patch-sample information or (2) combined current patch-sample with prior information (the distribution of resources among patches) to estimate patch quality, and (3) whether the kinds of information used depended on environmental variability. I established two environments that differed in amount of variation in patch subtypes and determined the use of information by assessing the correlation between the number of rewards obtained and the number of consecutive unrewarded patch probes just before patch departure. In the low-variance environment, most birds appeared to combine prior information with patch-sample information. Individuals using prior information foraged more efficiently than those that did not. In the high-variance environment, some birds appeared to combine patch-sample information with prior information, whereas others apparently relied solely on patch-sample information to estimate patch quality, with no difference in foraging efficiency. In both environments, prior information was used after approximately 25 patches were exploited.