Data are presented from a field study of aye-ayes (Daubentonia madagascariensis) in an area of degraded secondary forest in northeast Madagascar. Animals were followed by radiotelemetry for 3 months during the cool dry season, when productivity of the forest is at a minimum. Population density was variable. Male home ranges were larger and overlapped the range of at least 1 female. Male ranges also overlapped, and areas of overlap could be occupied by 2 animals simultaneously. Most of the parties were solitary, but aggregations were observed at feeding sites. All activity was observed during darkness, and aye-ayes were always found to nest singly during the daytime. These patterns conform to those described for other nocturnal solitary prosimians. The aye-ayes showed versatility in their locomotor patterns, enabling them to use all types of supports and forest levels. Dietary diversity was high, although a preference for flower nectar was noted. These results suggest that, despite their anatomical specializations, aye-ayes are able to exploit a wide range of resources within recently degraded forest. This ability seems to allow aye-ayes to remain active throughout the year, unlike certain other nocturnal lemurs which become torpid during the dry season.