Snakes Where? Not Here.

By Intern: Daija Sumor

08/08/2025 - The brown tree snake (BTS), a mildly venomous species from Papua New Guinea, arrived on Guam in the 1940s through military transport. With no predators, it spread fast and wiped out most of Guam’s forest birds. According to Wiles et al. (2003), 22 bird species were severely affected, with many disappearing or rapidly declining. Even though the BTS hasn’t established itself in the CNMI, a few have been found in cargo shipments during the 1990s and 2000s. The Brown Tree Snake Rapid Response Team was developed to respond to snake sightings in the CNMI and has been an important partner in ensuring that the CNMI remains snake free.

The Division of Fish and Wildlife’s (DFW)  Brown Tree Snake (BTS) Program began in the 1990’s and works actively to prevent the snake’s spread through inspections, monitoring, and rapid response. I was selected as an intern with the DFW BTS program. I assisted in monitoring snake traps placed at high-risk locations, like the seaport and airport. I recorded data from each trap and checked for signs of activity. I also observed inspections with the K9 unit, where dogs are trained to sniff out snakes in cargo and mail. Did you know snakes can go months without eating and still survive lengthy trips hidden inside shipments? While their first instinct is to climb up rather than stay grounded, BTS traps are placed high up on walls or fences to catch them as they climb up to higher safety. 

Being part of this team has shown me how just one snake can change the future of our island. Working alongside experts at cargo sites, airports, and even neighborhoods, I became part of an effort to protect our island's wildlife. I learned how important it is to protect what we still have for the environment, our culture, and the generations who will come after us. If we don’t take these extra precautions, we risk losing our unique birds and wildlife here in the CNMI. The importance of having the BTS program helps protect our island’s wildlife, environment, and  our way of life. I wrote this article to help educate the public and other students like me who are unaware of this issue. This unrecognized organization is crucial to our community and the safety of our island. I am grateful to be able to have the opportunity to see that effort up close.

Citation: 

Wiles, Gary J., et al. “Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam’s Avifauna.” Conservation Biology, vol. 17, no. 5, Oct. 2003, pp. 1350–1360, https://doi.org/10.1046/j.1523-1739.2003.01526.x.

Scientific Article Summary: 

The article Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna breaks down how badly the brown tree snake affected Guam’s birds. Out of 25 species, 22 were affected. Most of them either went extinct or dropped in numbers quickly. Some disappeared within just a couple of years. The birds that survived were mostly the ones that could nest in places snakes couldn’t reach. The study shows how serious this problem is and warns that if these snakes make it to other islands, we could see the same thing happen. That’s why containment and protection efforts are so important.