Exploration–exploitation trade-off features a saltatory search behaviour

Searching experiments conducted in different virtual environments over a gender-balanced group of people revealed a gender irrelevant scale-free spread of searching activity on large spatio-temporal scales. We have suggested and solved analytically a simple statistical model of the coherent-noise type describing the exploration–exploitation trade-off in humans (‘should I stay’ or ‘should I go’). The model exhibits a variety of saltatory behaviours, ranging from Lévy flights occurring under uncertainty to Brownian walks performed by a treasure hunter confident of the eventual success.

Foraging and Prey Search Behaviour of Golden Shiner (Notemigonus crysoleucas) Larvae

The juveniles of several species of freshwater fish search for zooplankton prey using a strategy intermediate between cruise and ambush: "saltatory search" (SS) or "pause–travel" search. Unlike ambush or cruise search, saltatory search involves scanning for prey throughout the search space and only during the brief stationary periods that punctuate repositioning movements. If no prey are located, these fish swim a short distance, stop, and scan again. In this paper, we describe the ontogeny of prey search in a cyprinid, the golden shiner (Notemigonus crysoleucas), a species whose search pattern has not been examined. Swimming and pursuit speeds and prey location distances increased with fish size. Golden shiner larvae searched for prey throughout the search space and only during the pauses that punctuated swimming movements. Only 1–10% of all of the stationary pauses that punctuated swimming movements were followed by attacks on prey. We conclude that golden shiner larvae employ a saltatory-search strategy similar to that described in other zooplanktivorous fish and their larvae.

A Reevaluation of the Search Cycle of Planktivorous Arctic Graylings Thymallus arcticus

Planktivorous arctic grayling, Thymallus arcticus, were previously believed to forage using a cruise strategy, searching for prey while swimming, while other planktivores have been found to search while stationary, a strategy termed "saltatory search." Comparing the predicted components of cruise and saltatory search, we observed that the planktivorous feeding behavior of the grayling was more consistent with the strategy of saltatory search. Although the grayling appear to swim continuously, they actually pause before making turns. Swim speed is reduced with decreased prey detectability, as would be expected of a cruise searcher; however, this behavior is believed to be a result of fin placement and body form constraints. Pause duration, run length, and run turn angle were observed to vary when grayling fed on prey of different sizes, all in a manner consistent only with saltatory search. The relationship between the ability to locate prey and the components of search suggests that the grayling alter the way they search for different prey, possibly as a means of increasing search efficiency.