02308nas a2200265   4500008004100000245004800041210004800089260000800137300001200145490000700157520157300164653002601737653001401763653001701777653003101794653002801825653002001853653002901873653001401902653001501916653003701931653002501968100001501993856003402008       2000                        eng d00aDung beetle movements at two spatial scales0 aDung beetle movements at two spatial scales  cNov  a323-3350 v913 aTo understand the dynamics of spatially structured populations, we need to know the level of movements at different spatial scales. This paper reports on Aphodius dung beetle movements at two scales: movements between dung pats within pastures, and movements between pastures. First, I test an assumption common to many recent models of spatially structured populations - that the probability of an individual moving between habitat patches decreases exponentially with distance. For dung beetles, I find sufficient evidence to reject this assumption. The distribution of dispersal distances was clearly leptokurtic, with more individuals moving short and long distances than expected on the basis of an exponential function. In contrast, the data were well described by a power function. I conclude that dung beetle movements include an element of non-randomness not captured by the simplistic exponential model. The power function offers a promising alternative, but the actual mechanisms behind the pattern need to be clarified. Second, I compare several species of Aphodius to each other. Although these species occur in the same network of habitat patches, their movement patterns are different enough to result in a mixture of different spatial population structures. Movements between pastures were more frequent the larger the species, the more specific its occurrence in relation to pat age, and the more specialized it is on cow dung and open pasture habitats. Within pastures, all species form "patchy" populations, with much movement among individual pats.10aAPHODIUS SCARABAEIDAE10abutterfly10acolonization10aeuphydryas-editha-bayensis10along-distance dispersal10amelitaea-cinxia10ametapopulation structure10amigration10apatch size10aproclossiana-eunomia lepidoptera10aresource utilization1 aRoslin, T.  u<Go to ISI>://000166017800013