You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Guam

Context:
Believed to be a stowaway on a U.S. military transport near the end of World War II, the brown tree snake (Boiga irregularis) was accidentally introduced to Guam, that previously had no native species of snake. It nearly eliminated the native bird population. The problem was exacerbated because the reptile has no natural predators on the island. The brown tree snake, known locally as the kulebla, is native to northern and eastern coasts of Australia, Papua New Guinea, and the Solomon Islands. While slightly venomous, the snake is relatively harmless to human beings. Although some studies have suggested a high density of these serpents on Guam, residents rarely see the nocturnal creatures. The United States Department of Agriculture has trained detector dogs to keep the snakes out of the island's cargo flow. The United States Geological Survey also has dogs capable of detecting snakes in forested environments around the region's islands.

Question:
Which animal was accidentally introduced into Guam?

brown tree snake