3 Little & Large Mammals of Fiji

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Sperm-Whale-scaled3 Little & Large Mammals of Fiji

What is a mammal? – a mammal is a group of backboned animals that nourish their young with milk from the mother’s special mammary glands (Jones, 2022).  Fiji has three very different mammals living in such diverse environments, these are the whale, bat, and the invasive mongoose, the whale is a yearly visitor to the Fijian islands as it migrates from the colder polar regions to warmer calmer water nursery areas to give birth, the mongoose introduced into Fiji in 1883 to help with controlling the rat infestations in the sugar cane plantations, and the native Bat, who is one…

Table of Contents

Whales of Fiji 

Little preparation is necessary to enjoy some of the great whale-watching spots, but sometimes a little planning can enhance the experience. Knowing typical whale behavior, the species you might see and the features that will help you identify the different species can really make a difference.  and add to your overall experience.  There are two types of whales; baleen and toothed. The key difference between them is the way they feed and what they have inside their mouth. (WDC, 2021)

Baleen Whales

Baleen whales are generally huge, yet they survive on the teeniest (and most abundant) animals in the ocean; they are filter-feeding specialists and target shoals of small fish or clouds of zooplankton and krill in the sea.  Their baleen plates are made from a material similar to human fingernails, they are strong, flexible, and feathered at the edges, rather like bristles on a brush. Huge volumes of seawater are strained through the baleen plates which sieve and retain little sea creatures in huge quantities.(WDC, 2021)

Baleen whales’ group sizes are generally small; they do not echolocate but do make a variety of sounds to communicate with each other. A large percentage of this type of whale migrates each year from the colder polar regions to the warmer oceans around the equator.  The main reason for the long migration is to provide an ideal environment for their newborn whales,  In colder polar oceans there is a much more abundant and diverse food supply available, but is not conducive to raising a newborn whale as it is a much more hostile environment.  The solution is to stay as long as possible in these feeding areas and swim to calmer water nursery areas to give birth.  Keywords – huge, filter-feeding specialists, no teeth, yearly migration

Toothed Whales

Toothed Whales are very social and live together in groups called pods, through these social interactions and their high intelligence, they teach and learn from each other, evolving as a pod as a whole.  As accomplished predators, they use a special sense called echolocation (a physiological process for locating distant or invisible objects (such as prey) by means of sound waves reflected back to the emitter by the objects); to hunt and to help them ‘see’ their underwater world, allowing them to navigate below 200 meters euphotic (sunlight zone), where there is rarely any significant light detection.  Keywords –  Teeth, social, pods, high intelligence, echo-location.

Things to look for when identifying a whale

You can determine species by identifying these different physical aspects.

  • Body Length
  • Presence of dorsal fin
  • Size and position of the dorsal fin
  • Shape and size of flippers
  • The shape of the head and general body shape
  • Presence of a beak
  • The shape of the blow
  • Body colour and patterns
  • Swimming characteristics
  • Presence of teeth or baleen and number of teeth

Whales and Dolphins in Fiji.


ImageCommon NameScientific NameWeightLengthLifespanInfo
Drawing of a Whale Humpback 1Humpback WhaleMegaptera novaeangliaeUp to about 40 tonsUp to about 60 feetAbout 80 to 90 yearsPDF
Drawing of a Whale Brydes 1Bryde’s WhaleBalaenoptera edeniAbout 90,000 pounds40 to 55 feetUnknown but sexually mature at 9 yearsPDF
Drawing of a sperm whale 1Sperm WhalePhyseter catodon15 tons (females) to 45 tons (males)40 feet (females) to 52 feet (males)Up to 60 yearsPDF
whale dwarf sperm 1Dwarf Sperm WhaleKogia simus300 to 600 poundsUp to about 9 feetUp to 22 years
Short Finned Pilot Whale 1Short-Finned Pilot WhaleGlobicephala Macroryhnchus2,200 to 6,600 pounds12 to 24 feet35 to 60 yearsPDF
Melon Headed Whale 1Melon-Headed WhalePeponocephala Electra460 pounds9 feet45 years
Pygmy Killer Whale 1Pigmy Killer WhaleFeresa AttenuataUp to 496 poundsUp to 8.5 feetUnknown
Cuviers beaked whale 1Cuvier’s Beaked WhaleZiphius Cavirostris4,000 to 6,800 pounds15 to 23 feet60 years
Gervais beaked whale 1Beaked WhalesMesoplodon Sp.About 2,640 poundsAbout 15 to 17 feetEstimated at least 27 years but may be up to 48 years
Short Beak Common Dolphin 1Short Beaked Common DolphinDelphinus DelphisAverage about 170 pounds (adults)About 6 feetAbout 40 yearsPDF
Dolphin Bottlenose 1Bottlenosed DolphinTursiops Truncates300 to 1,400 pounds6 to 13 feet40 to 60 years
Spinner Dolphin 1Spinner DolphinStenella LongirostrisApprox. 130 to 170 pounds4 to 7 feet (males slightly larger than females)20 yearsPDF
Rough toothed dolphin 1Rough-Toothed DolphinSteno Bredanensis350 pounds8.5 feet36 years
Table: Whales and Dolphins in Fiji.

Humpback Whales Bubble Net Feeding


Video: Humpback Whales Bubble Net Feeding

Kids Corner (Materials)

Marine Animal Colouring Pages by IFAW Animal Explores Humpback Whales

Visitor Advisory 1: The best time of the year to have a chance of seeing whales is early July to the end of November, Dolphins are all year round.

Bats of Fiji


Left: 10 Cent Coin ~ New front design features a Beka-Mirimiri, (Fiji Flying Fox) which is one of the world’s rarest mammals. It has only ever been recorded for certain on three occasions – most recently in 2009 by a team from NatureFiji-MareqetiViti, [a fully local environment NGO] and on all occasions in the upland cloud forests of Taveuni, at elevations near or higher than 1,000 metres. The Fiji Flying Fox is a very distinctive species with no close relatives. Because of its rarity, nothing is known of its behaviour and ecology. (Reserve Bank of Fiji) Right: The Fijian Flying Fox (Mirimiri Acrodonta) (Guy Bottroff Nature Fiji)
Left: 10 Cent Coin ~ New front design features a Beka-Mirimiri, (Fiji Flying Fox) which is one of the world’s rarest mammals. (Reserve Bank of Fiji) Right: The Fijian Flying Fox (Mirimiri Acrodonta) (Guy Bottroff Nature Fiji)

7 Fascinating Facts About Bats

  1. Bats are nocturnal animals, which means they are active at night.
  2. Bats are the only mammals that can truly fly, They have wings, which are made of skin stretched between thin finger bones.
  3. There are two groups of Bats – Megabats and Microbats
  4. The bat’s main diet consists of fruits, and insects, with the occasional beverage of nectar and a slight deviation to add some variety, including small frogs, lizards, and fish.
  5. The Fiji Flying Fox has been placed on the front of the 10-cent coin as part of the new fauna and flora currency collection released in 2013 by the Reserve Bank of Fiji, Post Fiji has also designed several collections of stamps to illustrate the importance and significance of Bats in Fijian Society
  6. Bats use to be eaten in Fiji as a fine delicacy.
  7. The National Trust of Fiji 2019 designated Nakanacagi Cave located on Vanua Levu, as the first Bat Sanctuary.

What is the difference between Megabats and Microbats?

Microbats – are small insect-eating bats, with a diet of flying insects caught after dark, they sometimes supplement bigger animals such as frogs, nectar, or fruit. Microbats are renowned for their very poor eyesight, they compensate for this with their extremely good hearing and a technique called echolocation. a physiological process for locating distant or invisible objects (such as prey) by means of sound waves reflected back to the emitter by the objects. Echolocation is used for orientation, obstacle avoidance, food procurement, and social interactions. (Lotha, 2021)  Cave Dwellers.

Megabats (Fruits Bats) – Megabats are the more social of the two types, relaxing and grooming together during the day.  Being much larger than the microbat, if you are lucky you might catch a glimpse of a few of these majestic mammals flying and gliding across the skyline, or hanging from the rooster trees waiting for the sun to descend. With their excellent eyesight and sharp sense of smell, they can travel long distances to find and feed on fruit, nectar, and pollen all across Fiji.  A large flying fox that travels forty or fifty kilometers in a straight line to a tree of fruit – and then flies home. (Ramel, 2020).

Observed Bat Species in Fiji.


Common NameScientific NameGroup
Fiji Flying Fox(Mirimiri acrodonta)Megabats
Pacific Flying Fox(Pteropus tonganus)Megabats
Samoan Flying Fox(Pteropus samoensis)Megabats
Fijian Blossom Bat(Notopteris macdonaldi)Microbats
Pacific Sheath-tail Bat(Emballonura semicaudata)Microbats
Fijian Free-tailed Bat(Tadarida bregullae)Microbats
Table: Bats of Fiji

Fijian Bat myths and legends

Fijian myths and legends tell us that flying foxes originated when a rat stole the wings of a heron, while another Fijian tale relates that it was the rat that first had wings while the flying foxes walked on four legs. The flying fox obtained his wings when he borrowed them from the rat and refused to return them. The rat now tries to retaliate by climbing tees and eating the flying foxes’ young, and this is why flying foxes carry their pups with them. (McCracken, 1993)

Anatomy of a Bat


Features Microchiropteran Bats (Britannica, 2013)
Features Microchiropteran Bats | Image: Supplied

G Ramel from Earthlife.org does an amazing job of describing in layman’s terms  How Do Bats Fly: The Mechanics Of Flight & Lift Explained, and Bat Anatomy 101: The Various Bones o The Wing & Skeleton. They are definitely worth a read.

Distribution, status, and conservation of the bats of the Fiji Islands.

The importance and significance of Bat colonies in Fiji have steadily grown over the last 20 years, leading authorities have conducted studies across 30 different islands to access their conservation status, and understand potential threats to their habitats and future existence. Factors threatening these species are variable but include small ranges, concentration in a reduced number of colonies, deforestation, over-harvesting, and introduced predators.(Palmeirim et al., 2007).  Some of the species play a keystone role as pollinators and seed dispersers invaluable forest ecosystems.(Scanlon et al., 2007).

Through these studies, several key sites were identified for the protection of the bat colonies (Map Below), combined with successful outreach and educational campaigns that have helped to stop villagers from hunting bats (historically local clans and community members hunted bats for food).   The more we understand about these amazing mammals, the more we become part of nature again.

Key sites for the protection of bats in Fiji
Key sites for the protection of bats in Fiji (Palmeirim et al., 2007)

IN DEPTH SUPPORTING ARTICLE: Dedicating Fiji’s First Bat Sanctuary at 12 Awe-Inspiring National Heritage Parks In Fiji

FURTHER READING: A world-first discovery – A study on the relationship between the Fiji blossom bat and the Fiji forest native plant, Kuluva made a world-first discovery of a new pollination system called chiropteropisteusis (bat reliant). “We discovered that the Kuluva flowers never opened on their own, and instead were being pulled off by blossom bats that were after the sugar-rich nectar inside,” says University of South Australia’s Associate Professor S. ‘Topa’ Petit. Link

Fiji Mongoose

The mongoose today, can be found everywhere throughout Fiji, so you are more than likely going to come across one on your travels, normally darting across the road from one sugar cane plantation to another. They are very agile and have great speed, so capturing a photo on your phone, will be a challenge.

The Mongoose can be described as having brown or gray grilled fur, ranging from 7 inches to 2 feet in length, with sleek long bodies and short legs, the feet have five toes and long claws, and tapered snouts, with a distinctive body size difference between the male and female mongoose. The small Indian mongoose has an average life span of 6 to 12 years. (Veron et al. 2009).

The Fijian Government introduced the Small Indian Mongoose (Herpestes auropunctatus) in the year 1883 across the two main islands of Viti Levu and Vanua Levu (Pernetia et al. 1978), with the intention of controlling the rodents and reptiles, that were devastating the sugar-cane fields, the main economic driving force for the island nation during this time, and is still one of the major social-economic institutions today, for rural farmers.

The sugar plantation farmers instantly saw the effectiveness of the introduction of the mongoose with the rodent and snake population heavily diminished, and the sugar cane crop yield improved. The short-term results were a resounding success, however, the long-term consequences are still being measured today, as the Mongoose has few predators, and can live across many diverse environments (dry and wet conditions including forest, scrub, grassland and gardens). They multiplied rapidly, crowding out other organisms and altering their habitat surrounding native species that have evolved to defend themselves primarily from other native predators were ill-equipped to handle attacks from new, unfamiliar enemies.

The Mongoose is generally solitary and hunts small animals by the day, in addition to rodents, they prey on birds (several species of ground-dwelling birds (Pernetta and Watling 1978)), all kinds of terrestrial vertebrates as well as a wide variety of invertebrates: moths, grasshoppers, beetles, wasps, flies, and spiders (Baldwin et al. 1952, Seaman and Randall 1962, Gorman 1975,) On some islands they have had a major effect on native snakes and diurnal lizards (Case and Bolger, 1991).

There was only believed to be one specie of Mongoose in Fiji, but by happenstance, when trapping mongoose as part of an investigation into the spread of leptospirosis around Suva, six large red-colored mongooses were also captured. The body measurements (weight, length, and hind-foot size) of these red-colored mongooses were significantly larger than a random sample of the grey-colored mongoose H. javanicus normally seen. (Craig G. Morley, Patricia A. McLenachan and Peter J. Lockhart, 2007), later to be confirmed by Nature Fiji to be the Indian Brown Mongoose (common name)

Mongooses in Fiji


Common NameScientific NameWeightLengthLifespan
Indian Brown MongooseUrva fuscaUp to 11 poundsHead to body length is 13-48 inches. Tail is about 7-13 inches.6-12 Years
Small Indian mongooseU auropunctata LCUp to 11 poundsHead to body length is 20.0–26.4 inches6-12 Years
Table: Mongoose in Fiji

Rumble Video: Mongoose in Fiji


Footnotes

  • Baleen whale – (suborder Mysticeti), also called a toothless whale, is any cetacean possessing unique epidermal modifications of the mouth called baleen, which is used to filter food from the water. Baleen whales seek out concentrations of small planktonic animals. The whales then open their mouth and take in enormous quantities of water. When the mouth is closed, they squeeze the water out through the sides, catching the tiny prey on the baleen’s bristles.
  • Insectivores – The common name applied to any specie of mammal that subsists primarily on insects, other arthropods, and earthworms. (Musser, 2018)
  • Krill and schooling fish – Krill are small crustaceans of the order Euphausiacea, and are found in all the world’s oceans. The name “krill” comes from the Norwegian word krill, meaning “small fry of fish”, which is also often attributed to species of fish. Krill is considered an important trophic level connection – near the bottom of the food chain.
  • Mammal – (class Mammalia), any member of the group of vertebrate (backbone) animals in which the young are nourished with milk from special mammary glands of the mother. (Jones, 2022)
  • 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. (Nature Fiji, 2015)
  • 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. (Nature Fiji, 2015)
  • Nectarivore – An animal that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of the sugar-rich nectar produced by flowering plants. (“Nectarivore”, 2022)
  • Tabua – A tabua is a polished tooth of a sperm whale that is an important cultural item in Fijian society. They were traditionally given as gifts for atonement or esteem, and were important in negotiations between rival chiefs. The dead men would be buried with their tabua, along with war clubs and even their strangled wives, to help them in the afterlife. Originally they were very rare items, available only from beached whales and from trade from neighboring Tonga.

References

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