Reproduction

A female brown tree snake produces between 2 and 11 eggs from which their young hatch. Each year they may produce up to two clutches. The eggs are deposited in a hollow log or rock crevice.

Female brown tree snakes have the ability to store sperm from a mating for several years which means they can breed years after the last encounter with a male.

The mother provides no care to their young while in the egg or after they hatch. The eggs incubate for 90 days and once they hatch they must feed for and defend themselves.

Hatchlings are colored yellow and begin to take on the adult coloration as they grow.

It has been noted that this species may have the ability to reproduce asexually (without mating).

Behavior

Brown tree snakes are primarily nocturnal but during winter they may emerge to bask in the sun.

These animals are rear fanged and venomous but until recently they have not been considered dangerous to humans. Recent cases in Guam have seen trouble breathing in children which were bitten.

To inject their venom they will grasp the prey and repeatedly chew it to inject the venom. If bitten by a snake one should always seek medical attention.

Most of their time is spent in the trees making this species arboreal. They can also scale rock faces and buildings in human inhabited areas. Some may seek shelter in tree hollows or sandstone caves.

Predators and Threats

Recorded natural predators of the brown tree snake include monitor lizards and larger sakes.

Introduced predators such as feral dogs, pigs, cane toads and cats may harm brown tree snakes.

When threatened the brown tree snake will raise up its forebody in a series of tight loops. They are considered aggressive and strike at a threat with little notice.

Their range has been expanded through introduction to Guam. Here they have caused devastation to the birds and bats which call the island home. They also cause damage to power infrastructure by crawling over the lines. Significant efforts are being invested in eradicating this population.

These animals are considered common with their population believed to be stable.

Brown tree snakes are present in the pet trade. Humans may affect them through fire and habitat loss.

Quick facts

These animals may also be know as the brown catsnake, culepla, banded tree snake, night tiger or Doll's eye.

Brown tree snakes are part of the world's largest snake family, the colubrids. This group includes 2000 species.