The turning away from the tree is almost symbolic of the incarnation. While many monkey species are still mostly at home in treetops, our ancestors once learned to appreciate the advantages of living on the ground – and began to walk upright. The reasons for this evolutionary step are many. Now the climate crisis and the global decline of forests are driving lemurs and other tree-dwelling primate species to the ground. This is reported by the authors of a study published in the journal "PNAS". The change of habitat could save the animals from extinction – however, such an adaptation is not possible for all species.
"The study began with a discussion among colleagues who had observed that certain populations of tree -dwelling primates spend more time on the floor than it was a few years ago," said biologist and main author Timothy Eppley from the San Diego Zoo Wildlife Alliance, 118 Scientists from 124 institutions together and collected more than 150,000 hours of observation data for 15 lemurs and 32 types of monkeys at 68 locations in America and Madagascar. All types of primates examined mostly live in trees.
Based on their data, the research group found that primates that eat little fruit and have a rather broad food spectrum spend more time on the ground than primates that eat fruit almost exclusively. Similarly, species that live in large groups and in rather hot and dry environments sought refuge on the ground more often than those that live in small groups and cool environments. "We see that primate species such as Eulemur fulvus and Eulemur rufifrons spend considerably more time on the ground in Madagascar's hot, tropical deciduous forests than their counterparts in the cooler, humid forests, probably to gain access to terrestrial water sources," the study said. It is conceivable that this protects the animals from the effects of forest destruction and climate change, said study leader Eppley.
Changes are happening too fast
In addition, primate populations that are located near human cities and streets climb down the trees much less often. "This result could indicate that the presence of man, which is often a threat to primates, affects the natural adaptability of the species to climate change," said biologist Luca Santini from the Roman University of Sapienza. For the species that tend to be less to terrestrial activities, the study authors write to quick and effective maintenance strategies to ensure their survival.
Basically, there have been several transitions from a tree-dwelling to a terrestrial way of life in the evolution of primates. Today's rapid changes, however, pose a serious threat, says Giuseppe Donati of Oxford Brookes University, another author of the study. "Although similar ecological conditions and species traits may have influenced previous evolutionary transitions from tree-dwelling primates, including hominins, to a soil-based way of life, it is clear that the current pace of deforestation and climate change puts most primate species at risk."
