Limited perceptual range and presence of conspecifics both affect the ability of pit-building wormlions to choose favorable microhabitats

Abstract

Abstract When choosing among several potential habitats, animals should strive to choose the habitat that provides the highest fitness. When animals choose habitats that do not provide the best possible fitness, there is a mismatch between habitat preference and performance. A common reason is that of limited information or perceptual range. Sit-and-wait predators are particularly deficient in information, due to spending most of their time in ambushing prey and, when they do travel, they cover only short distances. Here, we studied the effect of placing pit-building wormlions at a short distance from their preferred microhabitats, on the likelihood of them choosing it. When placed on the border between deep and shallow sand, fine and coarse sand, or dry and wet sand, wormlions chose the former in each case in vast proportions. However, the ability of wormlions to recognize and/or choose favorable habitats decreased sharply with distance, suggesting that they are limited in their perceptual range. We next examined whether wormlions relocate their pits following a continuous disturbance arriving always from the same side. Although they did so, their movement direction was unrelated to the direction of the disturbance. The preference of wormlions for a favorable, shaded microhabitat depended greatly on the location of a conspecific competitor: the favorable microhabitat was more attractive for wormlions when a competitor was more distant from it than when the competitor was located on the border between the favorable and unfavorable microhabitats. Our findings support previous studies indicating the limited perceptual range of pit-building predators.