According to activity signs left on the ground (feces, footprints, and traces of rooting), wild boars on the Doñana Reserve preferentially occupy the marsh edge and the shrub area and, to a lesser extent, the marsh itself and the dryer zones of shifting or stabilized dunes. Habitat occupation follows a seasonal pattern, with the marsh edge being used progressively more from autumn to summer. The period of farrowing extends almost throughout the year, although virtually no births occur during the summer or in early autumn. Our data suggest two periods of sexual activity: an extended one during the summer, and a shorter one (although of greater influence on births) in late autumn. The basic social unit is the other group; several units may join to form larger family groups, which may comprise females with their young, rusty individuals, subadults, and sometimes male adults, although the latter tend to be solitary.