MONOPOLIZATION IN A RESOURCE QUEUE - WATER STRIDERS COMPETING FOR FOOD AND MATES

The monopolization of resources plays an important theoretical role in the literature on competition for food and mates, We used 12 groups o f male water striders (Aquarius remigis) to: (1) test the general pred iction that monopolization of both food and mates decreases as the tem poral clumping of resources increases, (2) compare the efficiency of t wo indices of resource monopolization, coefficient of variation and Q (Ruzzante et al. 1996), and (3) quantitatively assess the resource que ue model of Blanckenhorn and Caraco (1992). Each group of six males co mpeted for both food items and mates released from the upstream end of a laboratory stream, The mean inter-arrival time for resource units ( food or females) was 10 min, with four levels of temporal clumping (va riance in inter-arrival time: 0, 25, 50 or 320 min(2)). As predicted, the monopolization of both food and mates decreased as the temporal cl umping of resource arrival increased, although monopolization was grea ter for food than for mates, Q detected the difference in monopolizati on of food and mates, whereas the coefficient of variation did not, be cause Q is independent of mean resource abundance. The resource queue model successfully predicted monopolization of both resource types, ex plaining 89% and 76% of variation in the proportion of food and mates acquired by the six males. The success of the model suggests that the scaling of handling time to the variance in resource inter-arrival tim e should play an important role in any general theory of resource mono polization.