Pteropus livingstonii has been allied to P. melanopogon (Nowak 1999), but it was later suggested that P. livingstonii and P. melanopogon are separate monotypic groups (Simmons 2005). Most recent genetic studies suggest P. livingstonii is a sister species to P. voeltzkowi (O’Brien et al. 2009, Chan et al. 2011). The suggested synonym P. livinstonei is an unjustified emendation by Anderson 1912 of P. livingstonii Gray 1866 (Smith and Leslie 2006).

Pteropus livingstonii is assessed as Endangered under criteria B1ab(i,ii,iii)+2ab(i,ii,iii) due to their limited extent of occurrence (EOO) of 1,602 km² and area of occupancy (AOO) of approximately 356 km². The species occurs in only two disjunct locations on Anjouan (total land area = 424 km²) and Mohéli (total land area = 290 km²) which are separated by ca 40 km, and both islands are small enough that a single severe weather event may impact all remaining habitat and the species’ population on either island negatively. There is a continuing decline in availability and quality of the remaining forest habitat due to continuing deforestation and agricultural activities, which in turn, leads to a continuing decrease in the size of the EOO and AOO.

Pteropus livingstonii is endemic to the Union of Comoros, occurring on the islands of Anjouan and Mohéli (Reason and Trewhella 1994, Goodman et al. 2010). The islands are approx. 40 km apart, a distance that many species of Pteropus can cross (Breed et al. 2010) and both islands are small enough (Anjouan: 424 km²; Mohéli: 290 km²) that a single severe weather event, such as a cyclone, can negatively impact the entire subpopulation on a single island. The bats inhabit forested areas between 200 and 1,100 m elevation above sea level: on Anjouan, which has a higher elevation profile, no important feeding or roosting sites are found below 450 m asl (Granek 2000, Daniel et al. 2017, Ibouroi et al. 2018b, Mandl et al. 2021). 

The species’ extent of occurrence (EOO) and area of occupancy (AOO) are based on habitat suitability modelling for P. livingstonii over the species’ elevation range of 200 to 1,100 m asl (Ibouroi et al. 2018b). A total area of suitable habitat for the species was 159.2 km² across both islands, consisting of two larger areas and several smaller disconnected patches. The EOO, calculated as a minimum convex polygon around the suitable habitat, is 1,602.7 km² which includes a considerable amount of non-inhabitable ocean area. The AOO, estimated by overlaying a 2x2 km grid over the suitable habitat and counting all occupied cells, is 316 km² across both islands.

Regular population surveys since 2012 found a maximum of 1,200 to 1,500 P. livingstonii individuals on Anjouan and a maximum of 300 to 400 individuals on Mohéli (Daniel et al. 2017, Ibouroi et al. 2018b, Mandl et al. 2024). While the distance between the islands can be crossed by Pteropus (Breed et al. 2010), there is genetic evidence that the subpopulations do not interbreed, potentially forming two distinct populations (Ibouroi et al. 2018a). We estimate the number of mature individuals of the total population to be between 1,200 and 1,500, based on capture records and demographic studies on wild Pteropus populations, where ~20-30% of individuals in a population were considered immature (Fox et al. 2008). 

The species has been monitored at known roost sites between 1992 and 2006 by researchers and the NGO Action Comores (Reason and Trewhella 1994, Sewall et al. 2007), followed by ongoing bi-annual surveys implemented by the NGO Dahari since 2014 and in collaboration with the Mohéli Marine Park since 2019 (Mandl et al. 2024). Over the past decade, the P. livingstonii population on the Comoros has been stable (Mandl et al. 2024). The population may have been stable before, but irregular sampling effort provided inadequate information to draw conclusions over a longer time period. While the bat population does not undergo severe fluctuations, variations in population estimates over time stem from the discovery of new roost sites, seasonal differences (Ibouroi et al. 2018b), and previous weather events, such as cyclones in early 2019 and 2023 (Mandl et al. 2024).

The species occurs naturally in lowland and montane tropical rainforests on the islands of Anjouan and Mohéli (Smith and Leslie 2006). Their roost trees, mainly consisting of old-growth individuals of endemic or native tree species, are generally located between 500 and 1,100 m asl (Granek 2000, Ibouroi et al. 2018b). Roost sites are often situated on deep slopes, in the vicinity of rivers (Granek 2000, Ibouroi et al. 2018b). Larger colonies can be found at densely forested sites, as the bats are strongly associated with increased presence of endemic and native trees (Granek 2000, Ibouroi et al. 2018b). The bats heavily rely on native, old-growth forest trees for roosting and feeding (Granek 2002) which are targeted for timber by the local population (Shepherd et al. 2019). Deforestation continues to be a major threat to the species as it results in habitat loss. Since 2016 at least three long-term roost sites have been lost or abandoned due to disturbance through landscape change or weather events. The suitable habitat for this species is projected to continue declining if no further conservation measures are put into place.

As long as large, native and endemic trees remain, this species seems to be able to survive in degraded forested habitat, with some feeding sites located in areas with extensive agricultural activities (Mandl et al. 2021). Pteropus livingstonii switches between roosts regularly but very little is known of their overall ecological requirements (Mandl et al. 2021). There seems to be clustered feeding sites throughout their range, but foraging behaviours and diet of the species are not well studied; preliminary data suggests a mixture of introduced and native fruit and flowers (Sewall et al. 2007).

Life history traits are available based on information from a captive population at Durrell Wildlife Conservation Trust in Jersey. Generation length can be estimated at 9.7 years based on data from captive individuals, closely related species, and taxonomically adjusted allometric equations (Sewall et al. 2007, Tidemann and Nelson 2011).

The greatest threat to the species is habitat loss through deforestation to make room for small-holder farms and plantations, and shifting agriculture, as well as urban development, including housing and roads. The Comoros had some of the highest deforestation rates worldwide between 1990-2010, with an estimated 5-8% forest loss per year in that period (Hawlitschek et al. 2011, Boussougou and Brou 2015, Doulton et al. 2015, Olagunju 2015, Shepherd et al. 2019). Between 2010 and 2020 the Union of Comoros experienced a net loss of 1.24% of forest area per year (FAO 2020). On Anjouan, the remaining forest fragments are mainly located on inaccessible, steep slopes and are under high pressure from the local population. Deforestation is largely driven by a need for farmland and timber for construction (Shepherd et al. 2019, Ibouroi et al. 2021). Large, old-growth, native trees, that are of particular importance to P. livingstonii are preferentially targeted for furniture-building and construction, with over 1,200 trees logged annually in the south-west of Anjouan alone (Shepherd et al. 2019). When soil becomes infertile, the process is repeated, shifting agriculture into more forested areas. Widespread ylang-ylang distillation for the international perfume market has led to an increase in demand for fuelwood and space for plantations. Despite local protective measures, forested areas continue to be cleared and there may come a point when the bats’ ecological needs may no longer be met.

Tropical storms impact the Comoros on average three times per year but the severity and the frequency of these storm in the Western Indian Ocean seem to be increasing due to climate change (Mavume et al. 2010, Mawren et al. 2022). Long-term effects of severe tropical storms on the bat population of Comoros are not understood, although comparative sites have shown increased mortality due to loss of critical resources (McConkey et al. 2004) – a scenario that is likely for Comoros, given the limited amount of forested area and the paucity of large, mature trees.

The species is not known to be used or traded.

Conservation actions in place: 

• A detailed conservation plan for P. livingstonii, developed by the NGO Action Comores and a range of stakeholders, was published in 2007 (Sewall et al. 2007). It outlines necessary actions to preserve the species, including habitat protection and management, environmental education, population monitoring, ecological research, ex-situ breeding, and international collaborations. It was adopted by the government of the Union of the Comoros as the national conservation strategy for this species. 
• Population monitoring was implemented by the NGO Action Comores in cooperation with Comorian communities between 1992 and 2006, establishing the basis for a long-term data set. Population and roost habitat surveys were continued by Engagement Communautaire pour le Developpement Durable (ECDD) of the Bristol Zoological Society and Durrell Wildlife Conservation Trust between 2010 and 2012 and have since been undertaken bi-annually by the Comorian NGO Dahari and the Mohéli Marine Park.
• The majority of the important long-term roost sites, as well as the remaining natural forest habitat are located within the protected areas Mount Ntringui National Park on Anjouan and Mohéli National Park.
• The NGO Dahari has been implementing a Conservation Agreements scheme since 2015. Seven roost sites, including key sites as identified by the Conservation Action Plan, are currently protected through the scheme, with planning underway to expand further across the landscape, including important feeding sites and resources, on Anjouan.
• A successful ex-situ breeding colony has been established in the United Kingdom at the Durrell Wildlife Conservation Trust since the 1990s. In 2023 another breeding colony was established at Northumberland Country Zoo, and additional breeding groups are planned for the future in at least one more zoo. These are meant as a genetic safety net for the species.
• A successful environmental education campaign, which raised local and international awareness of the species, and its threats was implemented by the NGO Action Comores until 2006. In addition, the campaign focused on training local personnel and increased participation in bat population surveys. The NGO Dahari continues to conduct awareness and outreach activities as part of their landscape conservation efforts.
• In the Union of the Comoros, the species is listed as an ‘integrally-protected species’ (Arrêté n°01/031/MPE/CAB, 14 May 2001), which prohibits the capture or detention of P. livingstonii individuals without a permit. This law also expressly prohibits the killing of flying fox individuals; transport, purchase, sale, export, or re-export of live or dead flying fox individuals or body parts; all disruption during the period of reproduction and raising of young; and the destruction of roosts. The species is also listed on Appendix II of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora).
• Community-based ecotourism programs are available on Mohéli: guided tours including visits to a roost site are maintained by the local community (Ouallah Deux).

Conservation actions needed:

• A new edition of the Conservation Action Plan is needed, incorporating the updated information on the species’ population, range and threats.
• Effective protection and restoration of important bat resources (such as roost sites and feeding trees) outside protected areas.
• Effective management of bat habitat within established protected areas.
• Replace the use of endemic trees for the construction and furniture trades. Alongside efforts to reduce tree cutting it will be important to work from the other end of the value chain and look at ways of replacing endemic species with imported timber or through planting appropriate non-native species.
• Improvement of agricultural practices towards more sustainable alternatives throughout Anjouan and Mohéli.

Research implemented & needed:

• Since the 1990s ecological research has been conducted into a) taxonomy, b) habitat quality, c) population genetics, and d) population trends of this species, with further research into spatial and feeding ecology underway.
• Important research into habitat trends and projected habitat loss for the upcoming decades is needed to inform conservation priorities.