The authors of the paper looked at how the availability of different tree species, including those of the genus Cecropia, affected the survival and reproduction rates of sloths. Given that these trees are the sloths’ favourite food, this specialist sloth species might be expected to spend most of its time in them. However, the authors found that at certain life stages, sloths may desert their favoured tree for other species.
Cecropia foliage consists of a fan of large leaves at the end of a long stem or branch with no other leaves on it, giving it an “open structure”. This means the tree does not make a good hiding place for young sloths, who may be more vulnerable than adults to predators like jaguars or eagles, even though they are quite well camouflaged. Similarly, mothers with babies may choose trees that have a thicker canopy as their maternity ward, moving back to the Cecropia tree when the baby is older.
This study may have significance for the conservation of other “specialised” herbivores across the globe, if it is found that sloths are not the only animal to be able to survive on less favoured plants. The authors remark that forests that are regenerating are better able to support specialist species than we thought – and given the current levels of deforestation globally, this must surely give us some hope for the future.