The Pacific sheath-tailed bat or Polynesian sheath-tailed bat (Emballonura semicaudata ) is a species of sac-winged bat in the family Emballonuridae found in American Samoa, Fiji, Guam, Micronesia, Palau, Samoa (where it is called pe'a vai, tagiti or pe'ape'a vai ), Tonga, and Vanuatu. Its natural habitat is caves. In 2013, Bat Conservation International listed this species as one of the 35 species of its worldwide priority list of conservation. It is threatened by habitat loss. There are estimated to be approximately 500 individuals of E. s. rotensis, a subspecies of the highly fragmented Emballonura semicaudata. Due to its dependence on forests and caves for roosting, it is known to roost in only three caves currently, E. s. rotensis is vulnerable to changes in the surrounding demographic and environmental changes reflective of indirect impacts caused by invasive species, in this case goats. Goats limit the carrying capacity of E.s. rotensis.