A waiting game between the black-bellied plover and its fiddler crab prey

Fiddler crabs (Uca sp.) provide a good example of prey whose antipredator behaviour places them in a ‘waiting game’ contest with their predators. After visually detecting an approaching predator, fiddler crabs typically retreat into a burrow. When this occurs, a crab must decide how long to wait for the predator to depart before re-emerging and potentially exposing itself to attack. Similarly, the predator must decide how long to wait for the crab to re-emerge before departing in search of other foraging opportunities. Hugie (2003, Behavioral Ecology,14, 807-817) recently presented an analysis of such a predator-prey waiting game. The model makes various predictions, including ones about the general shape of each player's waiting distribution (the distribution of waiting times one would expect to observe for individuals in that role). I present an empirical test of the waiting game during interactions between the black-bellied plover, Pluvialis squatarola, and the fiddler crab Uca princeps. As predicted by the model, the plovers' waiting distribution resembled a negative exponential function, whereas the waiting times of crabs were more variable and followed a positively skewed distribution. As further predicted, very little overlap occurred between the two players' waiting distributions and plovers rarely outwaited crabs. I conclude that the waiting decisions of the black-bellied plover and U. princeps support the general predictions of Hugie (2003) and result from a predator-prey waiting game.