The brown tree snake is an opportunistic feeder and has caused the extirpation or extinction of most of Guam’s native forest birds and lizards. The snake has eliminated 10 of the 13 native birds, many lizards species, and several bat species. As native bird populations decline, the snake population has shifted to feeding on abundant introduced lizards. Rodents, introduced birds, and bird eggs make up the rest of the snake’s diet on Guam. In its native range, the snake population is kept in check through natural processes such as disease, competition for food, and predation. Although similar processes likely occur on Guam, they are not enough to control the brown tree snake population.
Wildlife Negatively Impacted by
Tree Snake -
Species Historically Present on Guam
Species Historically Present on Surrounding Islands