Researchers from the University of Tennessee, Knoxville, are the first to thoroughly study the tree-climbing and basking behaviour in reptiles. (Agencies)
Vladimir Dinets, a research assistant professor in the Department of Psychology, and his colleagues observed crocodilian species on three continents - Australia, Africa and North America - and examined previous studies and anecdotal observations.
They found that four species climbed trees – usually above water - but how far they ventured upward and outward varied by their sizes.
The smaller crocodilians were able to climb higher and further than the larger ones. Some species were observed climbing as far as four meters high in a tree and five meters down a branch.
"Climbing a steep hill or steep branch is mechanically similar, assuming the branch is wide enough to walk on," researchers said.
"Still, the ability to climb vertically is a measure of crocodiles' spectacular agility on land," they said.
The crocodilians seen climbing trees, whether at night or during the day, were skittish of being approached, jumping or falling into the water when an approaching observer was as far as 10 metres away.
This response led the researchers to believe that the tree climbing and basking are driven by two conditions: thermoregulation and surveillance of habitat.
"The most frequent observations of tree-basking were in areas where there were few places to bask on the ground, implying that the individuals needed alternatives for regulating their body temperature," the authors of the study wrote in the journal Herpetology.
"Likewise, their wary nature suggests that climbing leads to improved site surveillance of potential threats and prey," they wrote.
The data suggests that at least some crocodilian species are able to climb trees despite lacking any obvious morphological adaptations to do so.
Researchers from the University of Tennessee, Knoxville, are the first to thoroughly study the tree-climbing and basking behaviour in reptiles.