Monitor lizards not invasive in many Pacific islands

An Asian water monitor (Varanus salvator) in Sri Lanka. Relatives of this lizard were once thought to be invasive species on a number of Pacific islands. Credit: Joshua Learn

Giant monitor lizards once thought to be invasive are actually native to islands in Palau, the Mariana archipelago and Micronesia. Researchers recently examined more than 50 monitor lizard specimens stored in museums around the world. They found a number of the lizards were species unique to the islands where they were found. DNA analysis also showed many of the lizards likely migrated to these islands before humans ever arrived and evolved in isolation for thousands of years. This contradicts a common belief that the giant lizards couldn’t have arrived to many of these remote islands by themselves, which in some cases has led to local persecution of the reptiles. The lizards are controlled in Cocos Island near Guam for example, in part to protect native birds like Guam rails (Hypotaenidia owstoni). The researchers hope this discovery will inform better wildlife management decisions on some islands.

Read more at The New York Times.