The chief one lies in falling asleep and tumbling out of the tree, but this is easily obviated by making the platform large enough for two or three men, two of whom may stretch out and sleep while the other one remains awake and keeps guard.
When I went to Africa I resolved never to climb a tree.

Later I resolved to try the tree method in order to get experience in a form of lion hunting that has many advocates among the valiant hunters who want lion skins at no expense to their own.
Of course, there are some perils connected with this method of lion slaying.

Mosquitoes may bite you, causing a dreadful fever that may later result in death in some lingering and costly form.

Also the biting ants may pursue you up to your aery perch and take small but effective bites in many itchable but unscratchable points.

These elements of danger are about the only ones encountered in the tree method of lion hunting, but then who could expect to kill lions without some degree of personal discomfort?
My one and only tree experience was not particularly eventful.