Whereas most bats are nocturnal, the Rodrigues flying fox is different. They are crepuscular and so are most active at sunset and sunrise when they leave their caves or trees to find food (4). This species hunts for night flying insects, using their wings as nets to draw the prey into the mouth. Bats belonging to the sub-order microchiroptera use echolocation to navigate in the darkness and hunt for insects, but the Rodrigues Flying fox belongs to the sub-order megachiroptera, and like other species in this group, they do not echolocate (8). Their ears are much smaller than those of echolocating bats, and instead they have evolved large eyes to see and hunt in the dark (6). As well as preying on insects, this species feeds on fruit, as its other common name indicates. By eating fruit these bats help scatter the seeds of fruit trees and pollinate many trees and shrubs (4). By living in large groups this species benefits from there being many more eyes to scan for danger, allowing more time for individuals to feed and mate. A female will give birth once a year to single offspring and occasionally have twins (6). The young will not be ready to reproduce until they are 1.5-2 years old, which compared to most other mammals of their size is a particularly slow reproductive rate. This is a crucial problem for their conservation because their reproductive rate is not high enough to withstand the increasing threats they face (5).

The Rodrigues flying fox gained its name because of its fox like large pointed ears, elongated snout and large eyes. Despite these features, this species is a bat, and is grouped under the order of mammals known as the chiroptera, which in Greek means 'hand-wing' (4). Of the mammals in chiroptera about one sixth, including this species, belong to the sub-order megachiroptera which, as mega implies, defines the larger bat species (4). The Rodrigues flying fox body is fairly small but its wing span can be up to 90 cm, with lightweight bones in the wings, facilitating flight (5). Two thin layers of skin are stretched between these finger-like bones, to make the bat's wing (6). This skin can amazingly stretch as much as three or four times the length of the bat's body giving it its huge wing span and is so thin that the wings are almost see through (7). Most flying fox species are brown but the Rodrigues flying fox is brightly coloured, and may be yellow, orange and red or silver and black. Males and females are similar in appearance, with the offspring also looking like the adults (6).

This species is confined to the western Indian Ocean island of Rodrigues (Mauritius). It was historically present on the island of Mauritius and Round Island (Mauritius), but is now extirpated from here. It appears to range up to around 200 m asl.

Pteropus rodricensis, also known as Rodriguez flying foxes or Rodriguez fruit bats, lives only on the Island of Rodriguez, a part of Mauritius located in the southern Indian Ocean east of Madagascar. Rodriguez is sometimes spelled "Rodrigues" in the literature.

Biogeographic Regions: indian ocean (Native )

Other Geographic Terms: island endemic

Historic Range:
Indian Ocean_Rodrigues Island

In the wild, the Rodrigues flying fox is only found on the island of Rogrigues in the southwestern Indian Ocean (1).

Pteropus rodricensis has thick fur and is usually a dark chestnut brown color with a layer of golden-brown covering the head, neck, and shoulders. It is often called a “Golden Bat;" however, its color can also vary between black, silver, yellow-orange, and red. The body is from 15 to 20 cm long, and the wingspan from 50 to 90 cm. Individuals weigh between 300 and 350 g. There is no tail.

Rodriguez flying foxes have large eyes and large, widely spaced ears. Each thumb and second finger has a claw, and the claw on the thumb is hooked for climbing. Males and females look the same, although males are generally larger.

The basal metabolic rate of these animals is reported at 134.9 cubic cm of oxygen per hour.

Range mass: 300 to 350 g.

Range length: 15 to 20 cm.

Range wingspan: 50 to 90 cm.

Average basal metabolic rate: 134.9 cm^3 oxygen/hour.

Sexual Dimorphism: sexes alike; male larger

Average basal metabolic rate: 0.753 W.

Habitat and Ecology

Systems

• Terrestrial

Due to the destruction of much of the natural environment of Rodriguez, Rodriguez flying foxes are confined to Cascade Pigeon, a small wooded valley on the island. These bats depend on dense rainforest habitat and roost in mature trees. These trees protect the bats from frequent cyclones.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest

This species is found living in mangroves and rain forests where they roost in trees or in caves and rock shelters. Flocks will normally favour a particular roosting site which they occupy for years, however, human disturbance and increased hunting pressure can cause colonies to relocate to new roosting sites in sub-optimal habitat (5).

Pteropus rodricensis, a frugivore, uses its sight and smell to find food. Rodriguez fruit bats are nocturnal. At dusk, individuals fly to fruit trees where they feed, rest, digest their food for several hours before returning to the roosting site. Rodriguez flying foxes drink fruit juices by crushing the fruit in the mouth and pressing the tongue against the upper plate. Juice and soft pulp are swallowed, but the bat spits out the skin, hard pulp, and seeds in the form of a pellet. The usual diet consists of bananas (Musa spp.), guavas (Psidium spp.), mangoes (Magifera spp.), papayas (Carica spp.), figs (Ficus spp.), breadfruit (Treculia africana), ripe tamarind pods (Tamarindus spp.), flowers, nectar, pollen and sometimes leaves or bark.

Plant Foods: leaves; wood, bark, or stems; fruit; nectar; pollen; flowers

Primary Diet: herbivore (Frugivore )

Pteropus rodricensis helps the rainforest to regenerate by dispersing seeds, which are spit out during feeding. This aids recovery of the forest after cyclones and human destruction. This bat also helps to pollinate plants and trees as it feeds off pollen.

Ecosystem Impact: disperses seeds; pollinates; creates habitat

There is no information available on predators of Rodriguez flying foxes.

Because Rodriguez fruit bats are frugivores, they do not echolocate. Instead, they have good vision and sense of smell, which allows them to find their food. Since scent marking is used to denote territories, olfactory communication must play some role in this species. No specific information on the communication of P. rodricensis is available; however, other members of the genus Pteropus are known to communicate with vocalizations, which vary depending up on the situation. Also, communication behaviors associated with mating involve vocal, visual, olfactory, and tactile signals. These bats are likely to resemble other members of the genus with respect to communication.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; acoustic

Information on the lifespan of this species is inadequate, but according to the Lubee Bat Conservancy, Pteropus species can live for approximately 30 years in captivity. The Lubee Foundation has a unique collection of species housed in captivity which includes various species of the genus Pteropus. Observation of other Pteropus species held in captivity indicate that individuals typically live between 9 and 17 years. Pteropus rodricensis is probably similar to other species of the same genus in terms of longevity.

Average lifespan

Status: captivity: 28 years.

Maximum longevity: 28 years (captivity) Observations: One specimen was at least 28 years old when it died in captivity (Richard Weigl 2005).

In general, mating for Rodriguez flying foxes is random and promiscuous. They form harems of one male and up to 8 females. Males attract and retain females using vocal and flight displays; these are also ways that males defend their territory, which they scent-mark by rubbing their head, neck, and chest on branches. Rodriguez fruit bats are very social animals; however, males tend to roost alone, whereas females of different harems may roost together in large colonies.

Mating System: polygynous

In the wild, Rodriguez flying foxes breed from October to December. Females produce only one offspring per breeding season. In captivity, however, breeding occurs throughout the year and a female can produce up to two offspring per year.

Gestation lasts from 120 to 180 days. Newborns typically weigh around 20 to 30% of the mother's weight. It usually takes the female about 40 minutes to give birth. In order to give birth, she hangs right-side up from her thumbs and catches the baby with the patagium of her wings.

It is believed that females give birth alone. However, an assisted birth in captivity has been observed. The female in labor was struggling to give birth and was in the wrong position; instead of being right-side up, she was in roosting position. Another female "tutored" the mother, showing her the proper birthing position, and helped stimulate birth by licking the mother's vagina. Only with the help of the "midwife" bat was the mother able to finally give birth. Although this is an isolated example of allomaternal care, it may not be unusual in this species. Because Rodriguez flying foxes usually give birth in areas that are difficult to observe, few births in the wild have been documented.

Rodriguez flying foxes are born fully furred. The eyes are wide open and the infant is alert. Because wings are underdeveloped, newborn pups cling to their mothers' bellies and drink from the teats under their mothers' armpits. The pups have sharp milk teeth, which firmly attach to the mother's fur. These milk teeth eventually fall out and are replaced by permanent teeth. The baby stays attached to its mother for about 30 days, until it becomes too heavy to carry, after which it is left at the roost. At about 50 days, the pup starts exploring the roost area and flaps its wings to strengthen them. Interactions with other pups in the roost help to develop social skills.

After 2 to 3 months, pups are flying and are fully weaned, although they still roost with their mothers. Rodriguez fruit bats do not become fully independent until 6 to 12 months after birth. These bats reach maturity at 1 to 2 years of age.

Breeding interval: Rodriguez flying foxes breed once yearly.

Breeding season: Rodriguez fruit bats breed seasonally from October to December.

Average number of offspring: 1.

Range gestation period: 120 to 180 days.

Range weaning age: 2 to 3 months.

Range time to independence: 6 to 12 months.

Range age at sexual or reproductive maturity (female): 12 to 24 months.

Range age at sexual or reproductive maturity (male): 12 to 24 months.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 45 g.

Average number of offspring: 1.

Sources have not provided any information on the various forms of parental investment by P. rodricensis. Females provide their young with milk and protection. Also, because pups have a limited ability to regulate their body temperature, the mother's selection and maintenance of a thermal environment are important aspects of parental care. The role of males is not exactly clear. Information on the parental investment of the family Pteropodidae is also limited.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Pteropus rodricensis is threated with extinction due to habitat loss. In addition to habitat destruction by humans, natural disasters like cyclones have significantly reduced the population. Although cyclones would have had little impact on this species historically, with reductions in rainforest cover, there is currently no buffer provided by additional rainforest when damage occurs because of storms.

Since 1992, Rodriguez flying foxes have been a part of the Species Survival Plan (SSP), and have been successfully breed in captivity. However, it has not yet been reintroduced to its native habitat.

US Federal List: endangered

CITES: appendix i

IUCN Red List of Threatened Species: critically endangered

Current Listing Status Summary

Status: Endangered
Date Listed: 01/23/1984
Lead Region: Foreign (Region 10) 
Where Listed:


Population detail:

Population location: entire
Listing status: E

For most current information and documents related to the conservation status and management of Pteropus rodricensis , see its USFWS Species Profile

Classified as Critically Endangered (CR B1 + 3d) on the IUCN Red List 2002 (1), and listed on Appendix II of CITES (3).

Population

Population Trend

Major Threats

This species is in grave danger of extinction in the wild on Rodrigues Island as a result of habitat loss, shooting and hunting for meat (5). These are believed to be the causes of its extinction in Mauritius where the species was once found in the wild. Now it is only observed there in captivity. These bats also face severe natural threats annually of tropical cyclones which blow animals out to sea where they die as well as destroy their habitats, depriving them of food and shelter (4).

Conservation Actions

In 1976 the Rodrigues fruit bats were on the brink of extinction. This species' survival in the wild seemed unlikely, prompting the Jersey Preservation Trust to collect 25 bats for a captive breeding project (5). This species is now part of an international Species Program (SSP) with 16 participating North American Institutes (5) and in 1992 was listed as 'Priority Grade 1' in the IUCN's Action Plan for Old World Fruit Bats, putting it into the most urgent conservation category (8). Over the years, habitat protection, conservation measures, breeding projects and community education programmes have allowed the Rodrigues Flying fox to make a slow but steady recovery. The population on the island has most recently been estimated at 3000 and rising (4), while Jersey zoo currently has some 70 bats. Their breeding projects are so successful they have to now keep males and females separately to limit the zoo's numbers. Jersey zoo also sent bats to 33 other institutions worldwide, which altogether now hold over 765 bats in captivity (4). Despite these encouraging signs they remain listed as Critically Endangered on the IUCN Red List since their numbers are still fragile and dependant on conservation measures (1). There are future plans to upgrade and expand the bats' accommodation areas in Jersey Zoo, make changes based on the genetic health of the bats to avoid inbreeding, and implement more conservation practices based on new knowledge of the bats, in order to help this species on the road to recovery (4) (8).

Although there are no known adverse effects of P. rodricensis on humans, some farmers mistakenly believe that they damage fruit orchards.

Rodriguez fruit bats pollinate crops and disperse the seeds of plants and trees. They also eat the fruits that are too ripe to be harvested.

Positive Impacts: pollinates crops