The Little Marianas Fruit bat, Pteropus tokudae, is native to Guam, located in the Marianas archipelago of the Pacific Ocean. P. tokudae is also thought to be endemic to Guam (Wiles, 1990b). According to a 1996 Endangered Species Information Systems report (Conservation Managment Institute 1996), no information has been uncovered regarding the migration patterns of P. tokudae. In fact, scientists are unsure whether the species, which may be extinct, was migratory.
There exists no information concerning nesting, cover, or shelter habitat for P. tokudae. The last recorded sighting of the species occurred in 1968, when hunters killed a female in an area described as a mature limestone forest (Conservation Management Institute 1996). This forest type is characterized by a low density of understory plants and a canopy 8-15 meters high, with scattered emergent trees (Conservation Management Institute 1996). Common plant species in this forest type include: Ficus prolix, Aglaia mariannensis, Guamia mariannae, Cycas circinalis, Neisosperma oppositifolia, Mammea odorata, Macaranga thopsonii, Pisonia grandis, Artocarpus mariannensis, Eleaocarpus joga, and Triphasia trifolia (Conservation Management Institute 1996).
P. tokudae was first discovered in 1931 during an expedition to Guam and was identified and described by G. H. H. Tate in 1934. Tate (1934) first described P. tokudae and documented a body length of 140-151 mm, a wingspan of 650-709 mm, and a body weight of 152 g. He also noted that the species bore a striking resemblance to Pteropus insularis - a fruit bat found in Micronesia - with the exception of P. tokudae was a race of P. insularis. The abdomen and wings were brown to dark brown with few whitish hairs. The mantle and sides of the neck were brown to light gold. The top of the head was grayish to yellowish brown with prominent ears, and the throat and chin were dark brown.
No information has been discerned about the reproductive pattern of P. tokudae.
The only observations regarding parental care were recorded in 1968, when a female was shot by hunters. The female was observed with a single juvenile, which was able to escape hunters. It is unknown if the mother was carrying the young or if the juvenile was flying with the mother, but the presence of a juvenile with its mother may indicate parental care several months after birth (Conservation Management Institute 1996).
Little is known about the food preference of the P. tokudae, but a 1996 Endangered Species Information Systems report (Conservation Management Institute 1996) suggested that the species probably foraged on fruits and flowers from evergreen shrubs typical of limestone forest types in the northern part of Guam.
Ecosystem roles are not known, but because of its foraging behavior, P. tokudae undoubtedly contributed to flower pollination and seed dispersal.
P. tokudae is considered a delicacy by the resident Chamorro culture of the Marianas (Wiles, 1990a). Although pollination and seed dispersal cannot be substantiated, its foraging behavior no doubt contributed to some pollination and distribution of seeds.
Data on historical populations are not available, but P. tokudae was always considered rare by hunters, residents, and collectors (Wiles, 1990b). No records of sightings exist after 1968, when a female was shot by hunters at the northern part of Guam (Wiles, 1990b). On August 27, 1984, P. tokudae was officially put on the Endangered Species List, along with seven other species of fauna native to Guam. It is likely, given the lack of records since 1968, that P. tokudae is extinct.
Although it is unclear which factor(s) led to the demise of P. tokudae, introductions of exotic species (Fritts et. al., 1998; Wiles, 1990b), forest alteration and degradation (Wiles, 1990b), and excessive hunting (Conservation Management Institute 1996); Fritts et. al., 1998; Wiles, 1990a; Wiles, 1990b) are all possible contributors.
Much of the native fauna of Guam evolved without the threat of any major predators (Wiles, 1990b). Wiles (1990b) noted that the brown tree snake (Boiga irregularis) was introduced to Guam sometime after 1945 and is implicated in reduction and extinction of several avifauna species. However, Wiles (1990b) could not determine the role of the brown tree snake regarding the decline in P. tokudae, and Fritts and Rodda (Fritts et. al., 1998) believed their loss was not attributable to the brown tree snake.
Habitat alteration, degradation, and destruction also played a role in the decline of native fauna, but it is unclear whether loss of habitat was a major contributor. Wiles (1990b) stated that forest destruction was only a minor factor in the decline of fruit bats (Pteropus spp.). Wiles (1990b) emphasized that fruit bats were already uncommon before forest loss was evident.
Wiles (1990b) and Hilton-Taylor (2000) agree that excessive over-harvesting due to hunting led to the decline of P. tokudae. Fruit bats are considered a delicacy by the resident Chamorro culture of the Marianas (Wiles, 1990a), and the increased use of firearms made harvesting more successful (Wiles, 1990b).
In 1987, the United States Fish and Wildlife Service developed a recovery plan for P. tokudae, but the report clearly stated that developed goals were inappropriate until it was discovered to exist (Conservation Management Institute 1996).
P. tokudae is most frequently referred to as the Little Marianas Fruit bat (Conservation Management Institute 1996). Other common names are Guam flying fox, Tokuda’s fruit bat, Tokuda’s flying fox and, by the Chamorro peoples of Guam, Fanihi (Conservation Management Institute 1996).
Jeffery Rebitzke (author), University of Michigan-Ann Arbor, Ondrej Podlaha (editor), University of Michigan-Ann Arbor.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
an animal that mainly eats fruit
An animal that eats mainly plants or parts of plants.
animals that live only on an island or set of islands.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
Conservation Management Institute, March 14, 1996. "http://fwie.fw.vt.edu/WWW/esis/lists/e051006.htm" (On-line). Accessed October 8, 2001 at http://fwie.fw.vt.edu/WWW/esis/lists/e051006.htm.
Fritts, T., G. Rodda. 1998. The Role of Introduced Species in the Degradation of Island Ecosystems: A Case History of Guam. Annual Review of Ecology, 29: 113-140.
Hilton-Taylor, C. 2000. 2000 IUCN Red List of Threatened Species. United Kingdom: Cambridge.
Tate, G. April 11, 1934. Bats From the Pacific Islands Including a New Fruit Bat From Guam. American Museum Novitates, 713: 1-3.
Wiles, G. 1990. Recovery Plan for the Mariana Fruit Bat and Little Mariana Fruit Bat. USFWS.
Wiles, G. Fall 1990. Giving Flying Foxes a Second Chance. Bats, 8: 3-4.