Volunteers lead fight vs. brown tree snakes on Dåno at MICC 2026

Volunteers searching for invasive brown tree snakes on Guam’s Dåno, or Cocos Island, have now logged more than 1,000 participants and captured dozens of snakes as part of a community-driven conservation effort, according to a presentation on the third day of the 8th Mariana Islands Conservation Conference held virtually last March 12.

Olympia Terral of Friends of Islan Dåno’ opened the session by outlining five years of volunteer searches aimed at protecting the island’s wildlife from the invasive predator.

“For Friends of Island Dano, July 1st, 2025 began our fifth year of searching for snakes on the island,” she said. “Over the years we’ve seen 55 snakes…with 40 snakes caught.”

The effort relies heavily on volunteers who conduct nighttime searches and periodic “BTS Blitz” events targeting the invasive brown tree snake, which devastated native bird populations in Guam.

Terral said the work is motivated not only by snake control but also by signs of wildlife recovery on the island.

“We intentionally check on [the birds] when we visit the island to monitor their progress,” she said, referring to white terns nesting in casuarina trees near the pier. “This gives us a huge boost in morale to see these birds successfully raising their young.”

The project has grown significantly since it began in 2021.

Terral said volunteers have conducted 163 searches with 1,063 participants, including 425 first-time volunteers.

“I feel very honored that we have facilitated over 1,000 people to come out to Dano,” she said. “Some people who grew up on Guam had never been to Dano, and they got to come out and feel the magic of birds in trees and lizards that you don’t see on Guam anymore.”

One capture last year involved a female snake carrying developing eggs, a discovery that underscored the urgency of suppression efforts.

After necropsy, Terral said researchers found “13 follicles or developing eggs,” adding, “So we got 14 snakes in one.”

Despite the progress, Terral said the goal remains complete eradication of brown tree snakes from the island.

“We want to go for full eradication,” she said. “We want to make history in this BTS world by having those snakes eradicated with everyone working on it.”

Terral also noted that Dåno could serve as a model for restoring native wildlife in Guam.

Quoting Guam Sen. Sabina F. Perez from the conference’s opening day, Terral said eliminating snakes on the island could demonstrate “what it could look like for us to be snake-free on Guåhan.”

“If we could get birds again…that’s a double plus for me,” Terral added.

Following Terral’s presentation, researchers from the U.S. Geological Survey, National Park Service and U.S. Fish and Wildlife Service discussed a separate brown tree snake removal effort at the Asan Beach Unit of War in the Pacific National Historical Park.

The team said citizen science volunteers have played a key role in the project.

“We’ve had 134 volunteers,” the researchers reported, noting that the community effort has helped remove 162 snakes through visual surveys, traps, and bait tubes.

Preliminary modeling results presented during the session suggest the snake population at the park may already be declining due to sustained removal efforts.

The researchers said the ultimate goal is to create conditions that would allow native birds—particularly the sihek and other species—to eventually return to the area.

Further monitoring, invasive ant control, and habitat improvements, including nest boxes, are part of the continuing restoration work.