Every individual makes a difference when the population is down to 150 animals, so Anne Brooke, wildlife biologist at Guam NWR, became foster parent to an orphaned Mariana fruit bat last winter.

The young female bat was found in June 2004 when it was about a month old, having been separated from her mother following a stretch of stormy weather. After several days on her own calling for her mother, the pup was brought to Tino Aguon, Acting Chief of the Guam Division of Aquatic and Wildlife Resources, and received 24-hour care for the first few months of her life.

Brooke, who is a fruit bat expert and has worked with them in American Samoa and throughout Polynesia, began spending time observing and interacting with the orphaned bat in mid-October. Together, Dr. Brooke and Mr. Aguon quickly realized that the young bat could be reintroduced into the natural environment and they began to work with FWS Ecological Services Honolulu Office towards having it transferred into FWS care.

Brooke and two volunteers, Jennifer Farley and Dusty Janecke, constructed a large cage with room for the bat to fly and placed it in a sheltered area near a cliff face in an area of Guam NWR that is closed to public access. In late December, Brooke and her team took over as the bat's foster parents.

The team visited the bat several times a day and fed her a variety of native fruits, weaning her off the apples and oranges that she had grown accustomed to eating. Brooke encouraged the young bat to fly through activities designed to strengthen her wings, and even introduced her to a brown tree snake, which is a predator of young bats. Feeling rain, wind, and seeing the world at night were all new experiences for the youngster.

In late January, the team decided it was time for the bat strike out on her own. The cage was left open, and as the team members were taking pictures of the bat, she flew up into a tree and climbed to the top. Food and water was left in the tree and by morning it had been eaten and the young bat had flown away for good.

The Mariana fruit bat is medium-sized and is found throughout Micronesia, including Guam and the Northern Mariana Islands. Fruit bats sleep during the day and forage at night, when they feed on a wide variety of fruits and flowers.

The Mariana fruit bat was listed as endangered on Guam in 1984, but subsequent research showed that the bats move between Guam and the Northern Marianas so the Fish and Wildlife Service reclassified the Guam population as threatened in 2005 and also listed the Northern Marianas populations as threatened.

Long-term surveys suggest that this species may disappear from Guam within five to ten years. They are most abundant in forested lands on Andersen Air Force Base, but the only remaining colony has less than 100 individuals and a small number of bats are scattered throughout the forests of northern Guam. The little Mariana fruit bat, also listed as endangered, has not been seen since 1968 and is believed to be extinct. Fruit bats are a traditional food in Chamorro culture so illegal hunting is a major threat, along with habitat loss and predation by brown tree snakes.

Guam NWR provides critical habitat for the Mariana fruit bat, the endangered Mariana crow, the Micronesian kingfisher and is home to the only mature Serianthes nelsonii tree in Guam.