Seasonality of fruiting and food hoarding by rodents in neotropical forests: consequences for seed dispersal and seedling recruitment

摘要

Fruit resource availability is highly seasonal in many tropical forests (Leigh, 1999; Wright et al., 1999). Within-year variation in the diversity and abundance of food resources imposes dietary restrictions on animals by requiring diem to consume what food is available in time and accessible in space. During periods of peak fruit abundance, many frugivores forage on die same species of fruiting trees (e.g. Guillotin et al, 1994). When fruit is scarce, diets diverge as vertebrates widi different body masses, home-range sizes and foraging tactics seek alternative resources in different ways. For example, peccaries (Tayassu tajacu) switch from fruit to worms, and spiny rats (Proechimys cuvieri and Proechimys guianensis) switch from fruit to insects(Henry, 1994a). The agouti (Dasyprocta spp.) and the acouchi (Myoprocta spp.), however, are exceptions. They remain frugivorous throughout the year, but alternate from pulp-centred to seed-centred diets during periods of high and low fruit production, respectively (Henry, 1999). In bodi South and Central American forests, these caviomorph rodents survive during lean periods by eating the seeds they buried when fruit was abundant (Smythe, 1970,1978; Hemy, 1999).