Bald Island
Encyclopedia
Bald Island is an island
that is located in the Great Southern region of Western Australia
. The island is 1.5 kilometre (0.93205910497471 mi) offshore from Cheynes Beach and is a protected area which was declared a World Conservation Union Category IA nature reserve (A Class A Nature Reserve (No 25869) in 1964. With an area of 8.09 square kilometres (1,999 acre) the island is one of the largest off the South Coast.
Composed almost entirely of granite
the island rises steeply from the ocean to a maximum height of 310 metres (1,017 ft).
The island was isolate
d around 10,000 years ago by rising sea levels.
) are found on the sheltered upper slopes of the island, while forested stretches of Rottnest Teatree (Melaleuca lanceolata
) are also found on the lower slopes.
The Bald Island Marlock (Eucalyptus conferruminata
) forms dense thickets on parts of the island.
In more exposed areas are covered by open heath and tussock species and closed shrub mostly comprising Melaleuca microphylla.
s - four skink
s and one gecko
. One of the species of skink, Ctenotus labillardieri , has evolved into a distinctive insular race on the island. There are no snake
s on the island. Marine mammal
s such as New Zealand Fur Seal
s and Australian Sea lions
inhabit Bald Island. There are a few mainland mammals including the quokka
. The island forms part of the Two Peoples Bay and Mount Manypeaks Important Bird Area
, identified as such by BirdLife International
because of its significance in the conservation of several rare and threatened bird species. It acts as an important breeding ground for Great-winged Petrel
s and Little Penguin
s.
population from the Two Peoples Bay Nature Reserve
. More of the rare species were sent in 2007 to bring the total population
to seven. The island was chosen due to its lack of predators such as cat
s, fox
es and snake
s.
Another endangered species translocated to Bald Island is the Noisy Scrub-bird
. In 1992 five males were taken from the Two Peoples Bay area and taken to Bald Island. In 1993 the area was surveyed to show that at least two had survived. In 1993 another three males and three females have been relocated to Bald Island. The estimated population of calling male birds on Bald Island in 2004 is 59 individuals.
Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...
that is located in the Great Southern region of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. The island is 1.5 kilometre (0.93205910497471 mi) offshore from Cheynes Beach and is a protected area which was declared a World Conservation Union Category IA nature reserve (A Class A Nature Reserve (No 25869) in 1964. With an area of 8.09 square kilometres (1,999 acre) the island is one of the largest off the South Coast.
Composed almost entirely of granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
the island rises steeply from the ocean to a maximum height of 310 metres (1,017 ft).
The island was isolate
Isolate
Isolate may refer to:* Genetic isolate, a population of organisms that has little genetic mixing with other organisms of the same species* Isolate , 2007* Isolate , 1992...
d around 10,000 years ago by rising sea levels.
Flora
The Island contains 104 species of plant. Large stands of Peppermint trees (Agonis flexuosaAgonis flexuosa
Agonis flexuosa is a species of tree that grows in the south west of Western Australia. It is easily the most common of the Agonis species, and is one of the most recognisable trees of Western Australia, being commonly grown in parks and on road verges in Perth.The species is commonly known as...
) are found on the sheltered upper slopes of the island, while forested stretches of Rottnest Teatree (Melaleuca lanceolata
Melaleuca lanceolata
Melaleuca lanceolata is a small tree or shrub in the genus Melaleuca, native to Australia. It has a number of common names including Black Paperbark, Moonah, Rottnest Island Teatree and Western Black Tea tree....
) are also found on the lower slopes.
The Bald Island Marlock (Eucalyptus conferruminata
Eucalyptus conferruminata
Eucalyptus conferruminata, Bald Island marlock, is a small tree or mallee with smooth, grey and whitish grey bark. Adult leaves are elliptical, elliptical, to 9 x 2.5 cm, concolorous, glossy, light green...
) forms dense thickets on parts of the island.
In more exposed areas are covered by open heath and tussock species and closed shrub mostly comprising Melaleuca microphylla.
Fauna
The island supports a good population of reptileReptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s - four skink
Skink
Skinks are lizards belonging to the family Scincidae. Together with several other lizard families, including Lacertidae , they comprise the superfamily or infraorder Scincomorpha...
s and one gecko
Gecko
Geckos are lizards belonging to the infraorder Gekkota, found in warm climates throughout the world. They range from 1.6 cm to 60 cm....
. One of the species of skink, Ctenotus labillardieri , has evolved into a distinctive insular race on the island. There are no snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s on the island. Marine mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s such as New Zealand Fur Seal
New Zealand Fur Seal
The Australian fur seal , or New Zealand fur seal or southern fur seal, is a species of fur seal found around the south coast of Australia, the coast of the South Island of New Zealand, and some of the small islands to the south and east of there...
s and Australian Sea lions
Australian Sea Lion
The Australian Sea Lion , also known as the Australian Sea-lion or Australian Sealion, is a species of sea lion that breeds only on the south and west coasts of Australia...
inhabit Bald Island. There are a few mainland mammals including the quokka
Quokka
The Quokka , the only member of the genus Setonix, is a small macropod about the size of a domestic cat. Like other marsupials in the macropod family , the Quokka is herbivorous and mainly nocturnal...
. The island forms part of the Two Peoples Bay and Mount Manypeaks Important Bird Area
Two Peoples Bay and Mount Manypeaks Important Bird Area
The Two Peoples Bay and Mount Manypeaks Important Bird Area is a 261 km2 tract of coastal and subcoastal land east of the city of Albany in south-west Western Australia. It is an important site for the conservation of several rare and threatened birds....
, identified as such by BirdLife International
BirdLife International
BirdLife International is a global Partnership of conservation organisations that strives to conserve birds, their habitats and global biodiversity, working with people towards sustainability in the use of natural resources...
because of its significance in the conservation of several rare and threatened bird species. It acts as an important breeding ground for Great-winged Petrel
Great-winged Petrel
The Great-winged Petrel or Grey-faced Petrel, Pterodroma macroptera, is a petrel. In New Zealand it is also known by its Māori name oi and as a muttonbird.- Taxonomy :...
s and Little Penguin
Little Penguin
The Little Penguin is the smallest species of penguin. The penguin, which usually grows to an average of in height and in length , is found on the coastlines of southern Australia and New Zealand, with possible records from Chile.Apart from Little Penguins, they have several common names...
s.
Translocations
Due to its location and lack of easy landing places on the shores of the island, it is in almost pristine condition. The island was chosen in August 2005 as a site for the translocation of a Gilbert's PotorooGilbert's Potoroo
Gilbert's Potoroo is an Australian marsupial, sometimes called a rat-kangaroo, that is critically endangered. It is described as pointed in the face and about the size of a rabbit. It lives in a restricted area on the southwest coast of Western Australia. Gilbert's Potoroos now exist on Bald...
population from the Two Peoples Bay Nature Reserve
Two Peoples Bay Nature Reserve
Two Peoples Bay is a protected area east of Albany. The area is accessible by 2WD vehicles. The bay itself, including two small secluded beaches, faces due east and is protected from the Southern Ocean by a headland formed by the granite massif of Mount Gardiner...
. More of the rare species were sent in 2007 to bring the total population
Population
A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
to seven. The island was chosen due to its lack of predators such as cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s, fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es and snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s.
Another endangered species translocated to Bald Island is the Noisy Scrub-bird
Noisy Scrub-bird
The Noisy Scrub-bird is a species of bird in the Atrichornithidae family. It is endemic to Australia.-Distribution and habitat:...
. In 1992 five males were taken from the Two Peoples Bay area and taken to Bald Island. In 1993 the area was surveyed to show that at least two had survived. In 1993 another three males and three females have been relocated to Bald Island. The estimated population of calling male birds on Bald Island in 2004 is 59 individuals.