Guam bat, bird officially extinct
By Pacific Island Times News Staff
The squeaking sound of the little Mariana fruitbat and the chirping of the bridled white-eye bird are gone forever. The U.S. Fish and Wildlife Service has officially declared these two Guam native species extinct.
The agency today issued a final rule removing the little Mariana fruit bat and bridled white-eye bird, along with 19 other species, from the list of species protected under the Endangered Species Act.
The final delisting also includes the Bachman’s warbler — a bird species previously found in Florida and South Carolina — as well as several Hawaiian species, including the large Kauai thrush, the Molokai creeper and the po’ouli. FWS also delisted two fish species — the San Marcos gambusia and the scioto madtom — and eight mussel species.
“We have determined that the 21 species that are the subjects of this rule should be removed from the list because the best available information indicates that they are extinct,” the service said, finalizing the rule initially proposed in 2021.
The agency attributed the extinction of the two Guam species to predation by the brown tree snake, alteration and loss of habitat and increased hunting pressure.
The bridled white-eye and little Mariana fruitbat were both listed as endangered on Aug. 27, 1984 and were included in a recovery plan that came too late in 1990.
“It is highly likely the brown tree snake, the primary threat thought to be the driver of multiple bird and reptile species extirpations and extinctions on Guam, has been present throughout the little Mariana fruitbat's range for at least the last half-century, and within the last northern refuge in northern Guam since at least the 1980s,” the agency said.
Only three specimens of little Mariana fruitbat have ever been collected on Guam, and no other confirmed captures or observations of this species exist.
The agency said the earliest records indicated that the species was already rare in the early 1900s.
"Therefore, since its discovery, the little Mariana fruitbat likely experienced greater susceptibility to a variety of factors because of its small population size," the agency said.
“ We conclude that it is extremely unlikely that the little Mariana fruit bat has persisted undetected on Rota or Guam considering the tremendous amount of effort that has gone into monitoring the fanihi on those islands,” the agency said.
The bridled white-eye bird was last observed in 1983, according to the Wildlife Service.
Endemic only to Guam, the bridled white-eye was a small green and yellow, warbler-like forest bird, weighing 0.33 ounces, with a characteristic white orbital ring around each eye.
The federal agency said there was sparse information about the life history of the species, and most were based on a few early written accounts.
“Available information indicates that the species was not able to persist in the face of environmental stressors, and we conclude that the best available scientific and commercial information indicates that the species is extinct," FWS said
The bridled white-eye was reported to be one of the more common Guam bird species between the early 1900s and the 1930s. However, reports from the mid- to late-1940s indicated the species had perhaps become restricted to certain areas on Guam
By 1981, the bridled white-eye was known to inhabit only a single 395-acre (160-hectare) limestone bench known as Pajon Basin in a limestone forest at Ritidian Point.