Material and methods
Study site
The maned sloths were monitored in a cabruca located at the
Cabana da Serra Farm (15◦1120S; 39◦233W) in the municipality
of Una, in the lowlands of southern Bahia, Brazil. The study site is
located near the Una Biological Reserve and the Private Reserve
Ecoparque de Una, and is crossed by the Maruim River (Fig. 1).
Approximately 67% of the land encompassed by Una Biological
Reserve and its buffer zone (extending 10km beyond the Reserve’s
borders) is covered by primary and secondary forests (Instituto
de Estudos Socioambientais do Sul da Bahia, unpublished data).
Shaded cacao plantations and rubber tree plantations account for
60% of the cultivated land and represent the main crops in the Una
Biological Reserve buffer zone (Araújo et al. 1998).
Average annual temperature is 24–25 ◦C, and annual precipitation
is 1600–2000mm (Gouvêa 1969). The vegetation in the study
area is tropical lowland rainforest (Oliveira-Filho and Fontes 2000).
The mature humid forest at Una Biological Reserve is characterized
by a canopy 25–30m tall, high abundance of epiphytes and vines,
and clearly defined strata (Amorim et al. 2008). In the cabrucas,
the understory of original forest is replaced by cacao shrubs, tree
canopy density is lower than in mature forests, epiphytes are usually
reduced to canopy layer and vines are minimal (Alves 1990,
2005; Sambuichi 2006; Sambuichi and Haridasan 2007; Cassano
et al. 2009). Traditional cacao agroforests exhibit great variation
in vegetation diversity and structure as a consequence of both
tree diversity of the original forest and the agroforest management
(Sambuichi 2006). The cabruca where the study was conducted has
well-developed canopy strata, although it is lower and thinner than
that of mature forests. Barreto and Cassano (2007) found 30 trees
(11 species) with a DBH> 10 cm in 0.1 ha, most were early successional
species. Inga edulis, Tapirira guianensis and Senna multijuga,
for example, together comprised over 50% of the trees. The cacao
plantation where the study was conducted received little management: weeding happened only twice during the four years of the
study, tree epiphytes were neither pruned nor removed from cacao
plants, and agrochemicals were not used.