The Mariana fruit bat habitat is native forest and bats have been observed throughout the elevation range of the Mariana Islands (USFWS 2010, U.S. Navy 2017). On islands inhabited by people or frequently visited by people, animals roost along cliffs where human disturbance is minimal and there is some protection from winds (Mickleburgh et al. 1992, Mildenstein and Mills 2013). As a medium-sized Old World fruit bat, this species is expected to have a large foraging range (e.g. Mildenstein 2012). Even on the largest islands, Mariana fruit bats are known to fly throughout the island’s forested area while foraging (Wiles et al. 1989, USFWS 2010, Mildenstein and Mills 2013, U.S. Navy 2017).

Studies of the species’ diet and role in seed dispersal are on-going. Local knowledge and observational study suggests 45 plant species (and/or congeneric species groups) are used as fruit bat food sources in the Mariana Islands including native and introduced fruits, flowers, and some leaves (U.S. Navy 2017). Although this species will use human-cultivated fruits, there is very little conflict with farmers on the Mariana Islands, probably because of how few bats remain on human-populated islands and the species’ status as celebrated part of Chamorro cultural heritage.

Pteropus mariannus ranges throughout the Mariana Island chain and is found on 14 islands including Guam and the islands of the Commonwealth of the Northern Mariana Islands (CNMI). According to remotely-sensed measurements, there are 485 km² of natural habitat available to this species throughout the archipelago (data from USFWS compiled in Mildenstein and Mills 2013, US Navy 2017). Based on research documenting the species' inter-island movements and foraging habits (Mildenstein unpublished data, Mildenstein and Mills 2013), it is assumed that the species' area of occupancy (AOO) will be, at maximum, the remaining 485 km² of available forest used for foraging/roosting.

The historic trade of this species led to this and many congeneric species being listed on Appendix I of CITES. Because the Mariana Islands are a protectorate of the USA, the species is also protected under the US Endangered Species Act (ESA). It was originally listed as Endangered only on Guam under the ESA, but because of the presumed level of connectivity of the metapopulation across islands, is now formally listed by the ESA as a Threatened species throughout the archipelago. A draft recovery plan was developed for the species (USFWS 2009) and is being updated, and management plans are being implemented on Rota by the (CNMI-DFW) and on Guam by Andersen Air Force Base, where most of the recent recordings of the species have been (US Navy 2017).

Active management and research are on-going on Guam and Rota. Throughout the archipelago, there are ongoing studies of this species include population size, distribution, and genetic connectivity, migration among islands, the species’ diet, habitat use, and ecological characteristics that promote seed dispersal.

Research is needed to track this species’ status, support management, and strengthen future assessments includes reproduction biology (seasonality, fertility and fecundity rates, and habitat requirements), habitat requirements and diet (which would also inform current reforestation planning), population-level effects of habitat degradation due to invasive plants and animals, mortality rates due to hunting, mortality rates due to typhoons and post-storm recovery time.