The response of peccaries to seasonal fluctuations in an isolated patch of tropical forest

I present results of a five year study on the ecology of white-lipped (Tayassu pecari) and collared peccaries ( T. tajacu) in a 2178 ha fragment of semideciduous Atlantic forest, São Paulo, Brazil. The purpose of the study was to investigate ecological factors related to the persistence of peccaries in a forest fragment and compare the vulnerability of the two species to problems associated with habitat fragmentation. Average home range size for the white-lipped peccaries was 1871 ha (90% harmonic mean estimate). This was similar to estimates available from continuous tropical forests. Despite area restrictions, white-lipped peccaries maintained distinct seasonal ranges with a minimum of overlap. Within seasons, subherds overlapped spatially, but were separated temporally. Average home range sizes of two radio-tracked collared peccary herds were 305 and 123 ha. To help explain nonrandom seasonal movements and range shifts by white-lipped peccaries, we used compositional analysis to compare use and availability of habitats and riparian zones in the fragment. Habitat preferences by white-lipped peccaries were different during the dry and wet seasons. Headwater palmito ( Euterpe edulis) swamps were most preferred in the dry season, while swamps and marshes were most preferred in the wet season. Preferences for habitat and riparian zone categories were herd-specific for collared peccaries and related to habitat quality and composition.; Data on fruit availability indicated that species diversity was greater in the wet season, but the total number and dry mass of fruits were higher in the dry season. The latter increase during the dry season was due to one palm, Syagrus romanzoffiana. White-lipped peccaries were the only ungulates that ate palmito, removing 59.8% of the fruits in the dry season and 29.5% in the wet. The higher removal rate of palmito fruits in the dry season corresponded closely with the range shifts and habitat preferences of white-lipped peccaries. Forest fragments with diminished fruit abundance or fruit diversity, or lacking key species such as S. romanzoffiana or E. edulis, will not support the nutritional needs of the white-lipped peccary populations. The persistence of habitat quality and diversity in the forest fragment appeared to explain the survival of viable peccary populations after 70 years of fragmentation-related pressures.