Behavioral and ecological mechanisms behind pattern formation

Environmental heterogeneity has been demonstrated to contribute to the movement pattern exhibited by animals to generate spatial pattern in their distribution. However, spatial pattern can still develop in relatively homogenous landscapes due to the way animals change the landscape through their interactions with it and through their interactions with other individuals within the landscape. We simulating a continuous and homogeneous resource patch and evaluated how patterns emerge using Rhyzopertha dominica adults that colonize newly harvested and stored wheat as a model system. Our findings suggest the existence of at least two non-mutually exclusive sources for pattern formation exist in this system. First, beetles were significantly attracted to areas where they had previously feed, thus over time the feeding behavior of the beetle influenced how they subsequently moved in the landscape of the patch and created a more patchy distribution. Second, presence of another conspecific individual within the homogenous patch changed the movement patterns, but the impact was dependent on the combination of sexes. Female and female pairs created a completely random pattern and male and male pairs were primarily random, except within a short range where there was a small increase in the frequency of clumpiness. Male and female pairs had a high frequency of clumped pattern thought out the spatial range evaluated. Clumped pattern resulted from the shorter average distance between insects and changes in female daily displacement and male path tortuosity. Our data suggests that animal feeding behavior increases heterogeneity, and after that movement patterns become less random and more associated with the new features added to the patch.