Nature Fiji.org project bats of fiji

Megabats and Microbats

Bats are the only native mammals in Fiji. There are six species in Fiji, out of which five are threatened or critically endangered. Bat species are divided into two groups, Megabats and Microbats. Very little is known of the endemic Fiji Flying Fox. Dedicated research on Fiji bats have been very scarce with only published reports in 1985 on cave inventories, and a broad documentation of bat species on 30 islands out of over 300 Fiji islands.

Megabats

Megabats include all flying foxes and are related to lemurs. They are vegetarian, have excellent night vision and most roost in trees but some are cave dwellers.

Fiji’s tree dwelling species are:

• Fiji Flying Fox (Mirimiri acrodonta) − Endemic to Fiji and critically endangered
• Pacific Flying Fox (Pteropus tonganus)
• Samoan Flying Fox − (Pteropus samoensis) – Threatened

Microbats

Microbats are shrew-like and use sonar to navigate and find their food such as insects but in some countries their food source includes small mammals or licking blood.

• Fijian Blossom Bat (Notopteris macdonaldi) – Vulnerable. Fiji represents the global population of this species
• Pacific Sheath-tail Bat (Emballonura semicaudata) – Critically endangered
• Fijian Free-tailed Bat (Tadarida bregullae) − Endangered

Achievements to date

• Rediscovery of the endemic Fiji Flying Fox in 2009. The only known records of this species were at the British Museum in 1978 and at the Australian Museum in 1990.
• Cave inventory for cave-dwelling bats on five islands were documented in three months with reported ten active cave sites.
• Discovered and documented an active cave of the Fiji Blossom Bat on Viti Levu, adding to the five known active caves of this species on the island
• Discovered and documented an active cave of the Pacific Sheath-tail Bat on Ovalau, adding to two known sites of this species on the island
• Production of awareness materials in Fijian and English on the six species of Fijian bats as well as cave guidelines when visiting active bat caves.

Further Action Needed

• Bats experts for training
• Continual monitoring, discovering new sites, assessing population size and documentation of findings. Available data will help researchers apply effective conservation actions.
• Funding to train students in dedicated research on bats ecology, habitats, diet and foraging habits, especially microbats.
• Protection of cave sites from continuous disturbance including fencing
• Engaging landowners with awareness program

• Nature Fiji.org / project / bats of fiji
• An Endangered Species Compendium

Mirimiri Fiji Flying Fox Photo Guy Bottroff

Description
The Fijian flying fox is the smallest of the three fruit bats found in Fiji, with adult body size (nose tip – anus) ranging from 18cm (females) to 20cm (males). [Please note that Fiji has six species of native bats; the other three species of bats are either insectivorous (2) or nectarivorous (1)]. The fur of the Fijian flying fox is a dull olive green to yellow in colour. The fur of the mantle and head is soft and khaki in colour. The hair over the back and rump is shorter in length, and khaki in colour for females, and a golden colour for males. The eyes are a distinguishing feature in that they are bright orange in colour. The Fijian Flying fox has characteristic cuspidate or pointed teeth, which are not found in any other Fijian fruit bat or flying fox.

Distribution
To date, this endemic flying fox has only been found in the montane cloud forest around Des Voeux Peak

Habitat Ecology and Behaviour
Until 2009, no ecological research had been undertaken on this flying fox and nothing was known about it other than its nocturnal habits and its apparent restriction to montane cloud forest over 900m. The cuspidate teeth suggest a diet of fruit and plant material that is tougher than typical for other Fiji fruit bats. Observations believed to be of these bats have revealed that they roost in pairs in epiphytic fern clumps (6-10m height above ground) on trunks of larger trees.

Threats
The fact that this species is an island endemic, with a very restricted range (one of the most restricted distributions of all bats) increases its risk of extinction in the wild. The Fijian Flying Fox habitat, the montane cloud forest, has a limited distribution in Fiji, and is also of global conservation concern because of its vulnerability to climate change and slow recovery after hurricanes. Hurricanes cause tree fall gaps which allow introduced species to enter the ecosystem, thus changing the unique species composition of montane forests. Land clearing for plantations along the mid slopes and in places the upper slopes of Taveuni’s forests may aid the movement of Fiji’s two other flying fox species (Pteropus tonganus andP.samoensis) up towards the summit, thus increasing the risk of competition with the small population of Fijian Flying Foxes.

Conservation Status
Recent partnered research between the University of South Australia and USP, with assistance by NatureFiji-MareqetiViti (through the Critical Ecosystems Partnership Fund) in 2009 led to the first ever capture and release of a pregnant Fijian flying fox caught on Des Veoux Peak in May 2009. This was the first confirmed sighting and capture of the bat after nearly 19 years. The search for the bat lasted for 40 days, but no more bats were observed or caught; confirming that this is indeed a very rare species.
There is an unconfirmed observation of this species on Delaikoro Peak in Vanua Levu and it is conceivable it may be found elsewhere in Fiji. However, this is yet to be confirmed and until research on the ecology and distribution of this bat is undertaken, it remains known only as a small population confined to the upland montane forests of Taveuni. Research is urgently needed to enable us to draw up and implement a conservation management plan, until that is done, this remarkable and Fiji’ only endemic bat is very vulnerable to extinction.
The people of Taveuni play a key role in the sighting and conservation of this species. NatureFiij-MareqetiViti is drawing up a species recovery plan that will outline future conservation actions – with the communities of Taveuni – for our Fijian flying fox.

Remarks and Cultural Significance
Recent partnered research between the University of South Australia and USP, with assistance by NatureFiji-MareqetiViti (through the Critical Ecosystems Partnership Fund) in 2009 led to the first ever capture and release of a pregnant Fijian flying fox caught on Des Veoux Peak in May 2009. This was the first confirmed sighting and capture of the bat after nearly 19 years. The search for the bat lasted for 40 days, but no more bats were observed or caught; confirming that this is indeed a very rare species.
There is an unconfirmed observation of this species on Delaikoro Peak in Vanua Levu and it is conceivable it may be found elsewhere in Fiji. However, this is yet to be confirmed and until research on the ecology and distribution of this bat is undertaken, it remains known only as a small population confined to the upland montane forests of Taveuni. Research is urgently needed to enable us to draw up and implement a conservation management plan, until that is done, this remarkable and Fiji’ only endemic bat is very vulnerable to extinction.
The people of Taveuni play a key role in the sighting and conservation of this species. NatureFiij-MareqetiViti is drawing up a species recovery plan that will outline future conservation actions – with the communities of Taveuni – for our Fijian flying fox.

References
Flannery, T. F. 1995. Mammals of the South-West Pacific and Moluccan Islands. Australian Museum/ Reed Books, Chatswood

Helgen, K. M. 2005. Systematics of the Pacific Monkey-faced
Bats (Chiroptera: Pteropodidae) with a New Species
of Pteralopex and a new Fijian Genus. Systematics and Biodiversity 3: 433-453.

Hill, J. E. and W. N. Beckon. 1978. A New Species of Pteralopex Thomas, 1888 (Chiroptera: Pteropodidae) from the Fiji Islands. Bulletin of the British
Museum (Natural History), Zoology 34: 65-82.

Palmeirim, J. M., A. Champion, A. Naikatini, J. Niukula, M. Tuiwawa, M. Fisher, M. Yabaki – Goundar, S. Thorsteinsdottir, S. Qalovaki and T. Dunn. 2007. Distribution, Status and Conservation of the Bats of the Fiji Islands. Oryx 41(4): 509 – 519.

Front Page Photo: Guy Bottroff, Jorge Kretzschmar

Pacific Sheath tail bat (Emballonura semicaudata)

The Pacific Sheath-tail bat is a medium sized bat with body size (nose tip – anus) ranging from 41-48 mm in males; and 44.4-45.5 mm in females. This species is sexually dimorphic, with females being larger than males.

Their fur is brown in colour. The Pacific Sheath-tail bat can easily be distinguished from other bats in Fiji in that it has a very small tail, only just projecting from the flight membrane

Distribution
In the Pacific Region, this species is found in Palau, the Marianna Islands, Caroline Islands, Tonga, Samoa, American Samoa, and Fiji (including Rotuma). The subspecies E. s. semicaudata is restricted to Fiji, Samoa and Tonga. In Fiji, the Pacific sheath-tail bat has been recorded from Rotuma, Ovalau, (Lomaiviti), Vatuvara Lakeba, Nayau, Cicia, Vanua Balavu (Lau), Yaqeta Island (Yasawas) as well as Taveuni, Vanua Levu and Viti Levu.

Habitat Ecology and Behaviour
There is limited ecological data available for this bat simply because it has been very little studied The Pacific sheath-tail bat or Bekabeka, as it is known locally, is an insectivorous, nocturnal bat that roosts colonially in caves. They usually share their roosting caves with White rumped swiftlets (Aerodramus spodiopygius). The Pacific sheath-tail bats leave their caves in the hundreds at sunset to forage under forest canopy. Some Pacific sheath-tail bats have been observed foraging in village areas. Pacific sheath-tail bats, like other insectivorous bats use echo-location to catch their prey and navigate through obstacles at night. These bats can determine the size and nature of objects in front of them just by analysing the sonar echoes they receive from the objects.

Threats
The threats causing the decline of this bat across the Pacific are not well understood. Feral cats are a known predator, human visitation to caves is clearly another, forest loss and indiscriminate insecticide use may be another. Feral cats (Felis catus) are one of the main predators of the Pacific sheath-tail bat, and these have been observed waiting at the entrances of Pacific sheath-tail bat caves to intercept the bats as they leave the roosting caves. Inside the caves cats jump up and take bats from low roosting sites. Because of the Pacific sheath-tail bat’s dependence on native forest for food, the persistence of a population is threatened by deforestation, especially on small islands. The Pacific sheath-tail bat tends to forage under forest canopy which offers them protection against strong winds. Without forest protection, the bats are easily blown away from their foraging habitat (and food) by strong winds. The increased use of insecticides in forests and plantations reduces the availability of prey and increases mortality in these insectivorous bats (through consumption of sprayed insects). Increasing visits by people to caves is another significant problem and there is a low level of awareness of the vulnerability of these bats by those who start new ecotourism ventures and the like. The surviving populations in Fiji today can only be found in relatively inaccessible caves, highlighting the negative impact of human visitation to bat caves. Bats generally have a slow reproductive rate, meaning that there is a slow recruitment of the new, young bats into the current population. Slow reproductive rates combined with the threats of feral cats, deforestation and increased disturbance to add to the risk of extinction of these distinctive bats.

Conservation Status
The subspecies E. s. semicaudata, which is restricted to Fiji, Samoa and Tonga, is on the verge of extinction in the Samoas, while there is no recent information from Tonga. In Fiji, the Pacific sheath-tail bat is declining rapidly; it may already be lost from Viti Levu (last observed in 1979), Kadavu, and some smaller islands in the Fiji group. The Fiji Pacific sheath-tail bat populations have probably been in decline since the late 1950s. Caves that were occupied by these bats between 1960 and 1973, had low populations by 1978, and were empty by 2005. As mentioned above, these surviving populations are restricted to relatively inaccessible caves.

Remarks and Cultural Significance
The subspecies E. s. semicaudata, which is restricted to Fiji, Samoa and Tonga, is on the verge of extinction in the Samoas, while there is no recent information from Tonga. In Fiji, the Pacific sheath-tail bat is declining rapidly; it may already be lost from Viti Levu (last observed in 1979), Kadavu, and some smaller islands in the Fiji group. The Fiji Pacific sheath-tail bat populations have probably been in decline since the late 1950s. Caves that were occupied by these bats between 1960 and 1973, had low populations by 1978, and were empty by 2005. As mentioned above, these surviving populations are restricted to relatively inaccessible caves.

References
Flannery (1995);
Gilbert (1984);
Palmeirim et al. (2005);
Palmeirim et al. (2007);
Tarburton (2002);
Watling and Pernetta (1978).
Front Page Photo: Paddy Ryan

Fiji Blossom bat (Notopteris macdonaldi)

The Fiji Blossom bat is quite small, with body size (nose-tip to anus) ranging from 98-110 mm in males; 95-107 mm in females.

Distribution
This bat is restricted to Vanuatu and Fiji. Within Fiji, the Fiji Blossom bat is only found on three islands: Viti Levu, Vanua Levu and Taveuni. On Viti Levu, they are known to roost in the Tatuba caves, Wailotua caves and Kalabu caves.

Description
The Fiji Blossom bat is quite small, with body size (nose-tip to anus) ranging from 98-110 mm in males; 95-107 mm in females. One of the distinguishing features of this bat is that it has an elongate muzzle, and a very long, free tail which resembles that of a mouse. The wings meet in the back midline, giving the back a wrinkled appearance.

Habitat Ecology and Behaviour
The Fiji Blossom bat is a nectar feeding bat and is dependent on good forest habitat. There is limited ecological data available. However, it is known to roost in caves with very high ceilings in the thousands in the lowlands. Amazingly, these bats travel all the way to the montane forests (highlands) to forage. These bats are faithful to their roosting sites, with one of the caves in Kalabu having been occupied by Fiji Blossom bats since 1912. Some populations give birth in August ¬ September.

Threats
The low populations in tourist frequented roosting caves, and deforested areas compared to inaccessible and intact forest areas indicate the negative impact of human visitation and deforestation on these native mammals. Viti Levu possibly only the only island with roosting populations or sites‚ no roosting sites have been found on Taveuni or Vanua Levu. Predation by introduced mammals such as the mongoose and cat are also a threat to roosting populations.

Hunting for the Fiji Blossom bats is a problem. Because they roost in hundreds, or in thousands in caves, they are more vulnerable and are an easy target for hunters who can kill them in large numbers.

The lack of ecological knowledge on this species is in itself an obstacle to determining potential threats and appropriate conservation management issues.

Conservation Status
The Fijian population probably represents half the global population of this bat which became extinct from Tonga in prehistoric times. While it is not rare in Fiji, bone collections suggest that it was once more widespread than it is today. It is its roosting in caves that makes it vulnerable to predation and hunting, and is therefore listed as Vulnerable under the IUCN Redlist of Threatened Species.

Ideally to conserve this species, hunting and roost site visits should stop. Further research should include searching for roosting sites on Vanua Levu.

Remarks and Cultural Significance
The Fijian population probably represents half the global population of this bat which became extinct from Tonga in prehistoric times. While it is not rare in Fiji, bone collections suggest that it was once more widespread than it is today. It is its roosting in caves that makes it vulnerable to predation and hunting, and is therefore listed as Vulnerable under the IUCN Redlist of Threatened Species.

Ideally to conserve this species, hunting and roost site visits should stop. Further research should include searching for roosting sites on Vanua Levu.

References
Flannery (1995);
Gilbert (1984);
Palmeirim et al. (2005);
Tarburton (2002);
Watling and Pernetta (1978).
Front Page Photo: Patrick Pikacha