Pteropus rodricensisRodriguez flying fox

Last updated:

Geographic Range

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. ("Bats at the Center: Pteropus rodricensis ", 2004)

  • Biogeographic Regions
  • indian ocean

Habitat

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. ("Bats at the Center: Pteropus rodricensis ", 2004)

Physical Description

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. (Braden, 2000; Kunz and Fenton, 2003; "Bats at the Center: Pteropus rodricensis ", 2004)

  • Sexual Dimorphism
  • sexes alike
  • male larger
  • Range mass
    300 to 350 g
    10.57 to 12.33 oz
  • Range length
    15 to 20 cm
    5.91 to 7.87 in
  • Range wingspan
    50 to 90 cm
    19.69 to 35.43 in
  • Average basal metabolic rate
    134.9 cm3.O2/g/hr
  • Average basal metabolic rate
    0.753 W
    AnAge

Reproduction

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. (Crichton and Krutzsch, 2000)

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. (Altringham, 1996; Braden, 2000)

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. (Bat Conservation International, 1995)

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. (Braden, 2000; Crichton and Krutzsch, 2000; SZG Docent, 2006; "Rodrigues Fruit Bat", 2006)

  • Breeding interval
    Rodriguez flying foxes breed once yearly.
  • Breeding season
    Rodriguez fruit bats breed seasonally from October to December.
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • 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

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. (Crichton and Krutzsch, 2000)

  • 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

Lifespan/Longevity

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. ("Bats at the Center: Pteropus rodricensis ", 2004)

  • Average lifespan
    Status: captivity
    28 years
    AnAge

Behavior

Pteropus rodricensis is a very social species. Females roost together in groups, forming a colony, whereas males roost alone. There is a dominance hierarchy among males, and they scent-mark their territory by rubbing the neck, head, and chest on branches. Although most members of the genus Pteropus are active in their roosts during the day, they only leave the roosting area to forage at dusk or in the night. These bats, restricted to a single island valley, are sedentary. ("Rodrigues Fruit Bat", 2005; "Bats at the Center: Pteropus rodricensis ", 2004)

Home Range

Rodriguez flying foxes require dense rainforests with large, mature trees. Not only do they roost in these trees, but the trees provide protection from harsh weather. There is no other information available pertaining to the home range of this species. ("Bats at the Center: Pteropus rodricensis ", 2004)

Communication and Perception

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. (Kunz and Fenton, 2003)

Food Habits

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. (Altringham, 1996; SZG Docent, 2006; "Rodrigues Fruit Bat", 2006; Altringham, 1996; SZG Docent, 2006; "Rodrigues Fruit Bat", 2006)

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

Predation

There is no information available on predators of Rodriguez flying foxes. (SZG Docent, 2006)

Ecosystem Roles

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. (SZG Docent, 2006)

  • Ecosystem Impact
  • disperses seeds
  • pollinates
  • creates habitat

Economic Importance for Humans: Positive

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. (SZG Docent, 2006)

  • Positive Impacts
  • pollinates crops

Economic Importance for Humans: Negative

Although there are no known adverse effects of P. rodricensis on humans, some farmers mistakenly believe that they damage fruit orchards. (SZG Docent, 2006)

Conservation Status

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. (SZG Docent, 2006)

Contributors

Valerie Popelka (author), University of Notre Dame, Karen Powers (editor, instructor), Radford University.

Nancy Shefferly (editor), Animal Diversity Web.

Glossary

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynous

having more than one female as a mate at one time

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Lubee Bat Conservancy. 2004. "Bats at the Center: Pteropus rodricensis " (On-line). Lubee Bat Conservancy. Accessed March 30, 2006 at http://www.lubee.org/center-bats-pteropus_rodricensis.aspx.

Akron Zoo. 2005. "Rodrigues Fruit Bat" (On-line). Akron Zoo. Accessed March 31, 2006 at http://www.akronzoo.com/learn/Rodrigues.asp.

Wildlife Conservation Society. 2006. "Rodrigues Fruit Bat" (On-line). Saving Wildlife. Accessed March 30, 2006 at http://www.wcs.org/5675/aoljump/rodriguesfruitbat.

Altringham, J. 1996. Bats: Biology and Behavior. Oxford: Oxford University Press.

Bat Conservation International, 1995. The Tale of the Flying Fox Midwife. Bats, 13/2: 16-17. Accessed March 30, 2006 at http://www.batcon.org/batsmag/v13n2-7.html.

Braden, M. 2000. "Fact Sheet: Rodrigues Fruit Bat" (On-line). Behavior Matters. Accessed March 31, 2006 at http://www.letus.org/bmatters/animals/bat.html.

Crichton, E., P. Krutzsch. 2000. Reproductive Biology of Bats. London: Academic Press.

Kunz, T., M. Fenton. 2003. Bat Ecology. Chicago: The University of Chicago Press.

SZG Docent, 2006. "Rodrigues Fruit Bat" (On-line). Accessed April 01, 2006 at http://www.szgdocent.org/resource/ff/f-batrod.htm.