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North Island (Houtman Abrolhos)
Encyclopedia
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Houtman Abrolhos
The Houtman Abrolhos is a chain of 122 islands, and associated coral reefs, in the Indian Ocean off the west coast of Australia. Nominally located at , it lies about eighty kilometres west of Geraldton, Western Australia...
, a coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
archipelago
Archipelago
An archipelago , sometimes called an island group, is a chain or cluster of islands. The word archipelago is derived from the Greek ἄρχι- – arkhi- and πέλαγος – pélagos through the Italian arcipelago...
in the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
off the coast of Mid West 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...
. Located about 14 km (9 mi) from the nearest island group, it is one of the largest islands in the Houtman Abrolhos, and one of the few to support dune systems. It has relatively diverse flora dominated by chenopod shrubs and fauna that includes the introduced Tammar Wallaby
Tammar Wallaby
The Tammar Wallaby , also known as the Dama Wallaby or Darma Wallaby, is a small member of the kangaroo family and is the model species for research on kangaroos and marsupials. It is found on offshore islands on the South Australian and Western Australian coast...
, around seven species of reptile, and about 15 resident bird species.
First recorded and surveyed in 1840, North Island has been a seasonal camp for western rock lobster
Western rock lobster
Panulirus cygnus is a species of spiny lobster , found off the west coast of Australia. Panulirus cygnus is the basis of Australia's most valuable fishery, making up 20% of value of Australia's total fishing industry, and is identified as the western rock lobster.-Description:The species has five...
fishermen since the beginning of the 20th century, and this remains the principal focus of human activity on the island. There is also a small amount of tourism, though for the most part it is reserved
Nature reserve
A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...
as conservation habitat for vegetation communities and rare birds.
Discovery
The earliest recorded sighting of North Island occurred in May 1840, during the third survey voyage of HMS BeagleHMS Beagle
HMS Beagle was a Cherokee-class 10-gun brig-sloop of the Royal Navy. She was launched on 11 May 1820 from the Woolwich Dockyard on the River Thames, at a cost of £7,803. In July of that year she took part in a fleet review celebrating the coronation of King George IV of the United Kingdom in which...
, commanded by John Clements Wickham
John Clements Wickham
John Clements Wickham was a naval officer, magistrate and administrator. He was a Lieutenant on HMS Beagle during her second survey mission from 1831 to 1836, which took the young naturalist Charles Darwin on what became the subject of his book, The Voyage of the Beagle...
. It was sighted from the peak of Flag Hill
Flag Hill (Houtman Abrolhos)
Flag Hill is the highest hill on East Wallabi Island, and the highest point in the Houtman Abrolhos, an archipelago off the coast of Western Australia. It is located in the north-east of the island; its gazetted location is , but in fact it is located somewhat east of there at about...
on East Wallabi Island in early May, explored on 22 May, and given its name due to "its relative position to the remainder of Houtman's Abrolhos". Before he left the island, Wickham left a letter in a bottle atop the highest hill, which he accordingly christened Record Hill
Record Hill
Record Hill is the highest hill on North Island in the Houtman Abrolhos. It is located in the southwest of the island; its gazetted location is , but in fact it is located about 150 metres north of there at...
.
A map of the island first appeared in 1845 on a British Admiralty chart entitled "The Houtman Rocks". The following year, Wickham's lieutenant, John Lort Stokes
John Lort Stokes
Admiral John Lort Stokes, RN was an officer in the Royal Navy who travelled on HMS Beagle for close to eighteen years.Stokes grew up in Scotchwell near Haverfordwest, Pembrokeshire. He joined the Navy on 20 September 1824...
, published the first account of the island in his Discoveries in Australia
Discoveries in Australia
Discoveries in Australia; with an account of the coasts and rivers explored and surveyed during the voyage of H.M.S. Beagle, in the years 1837-38-39-40-41-42-43, by command of the Lords Commissioners of the Admiralty...
. He observed:
Development of industry and infrastructure
A western rock lobsterWestern rock lobster
Panulirus cygnus is a species of spiny lobster , found off the west coast of Australia. Panulirus cygnus is the basis of Australia's most valuable fishery, making up 20% of value of Australia's total fishing industry, and is identified as the western rock lobster.-Description:The species has five...
fishery developed on the island in the early 20th century. There are records of the island being used as a base for crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
ers as early as 1902, and for many years it was used as an anchorage by anglers
Angling
Angling is a method of fishing by means of an "angle" . The hook is usually attached to a fishing line and the line is often attached to a fishing rod. Fishing rods are usually fitted with a fishing reel that functions as a mechanism for storing, retrieving and paying out the line. The hook itself...
. It was not until 1947, however, that a seasonally inhabited permanent camp was established there. According to former crayfisher Ron Bertelsen, the first camp was established by skippers George Barker and George Nelson and deckhand John Long, who relocated there when lobsters around Pigeon Island
Pigeon Island (Houtman Abrolhos)
Pigeon Island is a small island located need the middle of the Wallabi Group of the Houtman Abrolhos, an archipelago off the coast of Western Australia. It is almost entirely given over to Western Rock Lobster fishers' camps, and as a result is far more disturbed than most other islands in the...
grew scarce. They camped at the southern end of North Island in a camp initially built from packing case timbers. A local carrier boat, the Betty Margaret, serviced the camp. From about 40 seasonal inhabitants in 1940, the population grew to about 130 by 2003. An airstrip was built in 1979.
Visits by naturalists
A number of naturalists have visited the island, starting with the Percy Sladen Trust Expedition to the Abrolhos Islands in 1913. This expedition spent little time on North Island, as shore collecting was not very successful there, and other islands appeared better suited to their work. Expedition members nevertheless published substantial information about the island, including a description of its physiography and a list of its vertebrateVertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s.
Australian ornithologist Dom Serventy visited the island in 1945 but left no published account. In 1959, a group from the University of Western Australia
University of Western Australia
The University of Western Australia was established by an Act of the Western Australian Parliament in February 1911, and began teaching students for the first time in 1913. It is the oldest university in the state of Western Australia and the only university in the state to be a member of the...
's Department of Zoology, accompanied by the English botanist Mary Gillham
Mary Gillham
Dr Mary Eleanor Gillham is an English naturalist, university lecturer, and writer, currently resident in Radyr, in Cardiff, Wales....
, travelled to the island; a brief article on its physiography, vegetation and vertebrate fauna was published the following year by Glen Storr. More recent visitors have included P. R. Howden in 1974, Robert Ivan Taylor Prince in 1976, Ronald Eric Johnstone
Ronald Eric Johnstone
Ronald Eric Johnstone is an Australian ornithologist who worked for the Western Australian Museum for many years. The bat species Otomops johnstonei is named in his honour.-Publications:...
in 1981 and 1983, Phillip Fuller in 1992, and Judith Harvey and Vanda Longman in 1999.
Geography
Wallabi Group
The Wallabi Group is the northern-most group of islands in the Houtman Abrolhos. Nominally located at , it is 58 kilometres from the Australian mainland, and about 9 kilometres from the Easter Group....
by the 14 km (9 mi) wide South Passage
South Passage (Houtman Abrolhos)
South Passage is a 14 kilometre wide strait that separates the outlying North Island from other islands in the Wallabi Group of the Houtman Abrolhos island chain, in the Indian Ocean off the coast of Western Australia. It is nominally located at ....
. Despite this separation, it is sometimes treated as part of that group. It is roughly diamond-shaped and is approximately 2 km ( mi) long from south to north, and km (1 mi) from west to east, giving it an area of about 180 hectare
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
s (450 ac
Acre
The acre is a unit of area in a number of different systems, including the imperial and U.S. customary systems. The most commonly used acres today are the international acre and, in the United States, the survey acre. The most common use of the acre is to measure tracts of land.The acre is related...
).
Two high points are named Record Hill
Record Hill
Record Hill is the highest hill on North Island in the Houtman Abrolhos. It is located in the southwest of the island; its gazetted location is , but in fact it is located about 150 metres north of there at...
and Latitude Hill
Latitude Hill (Houtman Abrolhos)
Latitude Hill is a hill on North Island in the Houtman Abrolhos. It is located in the east of the island. at ....
. These are the only gazetted places on the island, although some other features have informal names: The most northerly and southerly point on the island have been called "North Point" and "South Point" respectively, and in 1960 a high point in the northwest corner of the island was referred to as "Northwest Hill".
On the eastern side is a seasonally inhabited permanent fishers' camp. There is an unnamed lighthouse on the western side, a trig point
Trig point
A triangulation station, also known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon or trig point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity...
on the eastern side, and a gravel airstrip near the centre.
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Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
flat. This extends about km (1 mi) to the west of the island, and over 3 km (2 mi) to the north and south, but the reef margin lies quite close to the island on the eastern side. Most of the reef is not navigable, but a passage
Strait
A strait or straits is a narrow, typically navigable channel of water that connects two larger, navigable bodies of water. It most commonly refers to a channel of water that lies between two land masses, but it may also refer to a navigable channel through a body of water that is otherwise not...
through the reef just north of the island is named Suda Bay Passage
Suda Bay Passage
Suda Bay Passage is a channel through reef just north of North Island in the Houtman Abrolhos. Located at , it is named after the Suda Bay, which was used for lobster fishing around North Island in the late 1940s....
; one just south of the island is named Barker Passage
Barker Passage
Barker Passage is a channel through reef about a kilometre south of North Island in the Houtman Abrolhos. Its gazetted location is , but it is actually located nearly 2½ kilometres west of there, at approximately ....
; and there are a few breaks or channels on the eastern side of the island where boats may obtain shelter in bad weather. An area of reef immediately north of the island is named The Flat
The Flat
The Flat is an anchorage just north of North Island in the Houtman Abrolhos.It is located at ,...
, and at the northern extreme of the reef is a breaker named The Big Breaker
The Big Breaker
The Big Breaker is the most northerly geographic feature in the Houtman Abrolhos islands in the Indian Ocean off the west coast of Australia. It is located at the extreme tip of a reef that extends about three kilometres north of North Island. Its gazetted location is , but in fact it is located...
. About 200 m (660 ft) west of the island is a small rock informally known as "Shag Rock", but with no official name; it differs from Shag Rock
Shag Rock (Houtman Abrolhos)
-Geography:It is located at , about east of West Wallabi Island. Its nearest neighbour is Plover Island, about away. The island has an area of about , and a maximum elevation of . It is uninhabitated, and devoid of human infrastructure....
in the Wallabi Group further south.
Like the rest of the Houtman Abrolhos
Houtman Abrolhos
The Houtman Abrolhos is a chain of 122 islands, and associated coral reefs, in the Indian Ocean off the west coast of Australia. Nominally located at , it lies about eighty kilometres west of Geraldton, Western Australia...
, North Island is Australian territory. It is a part of Western Australia, and falls within the boundaries of the federal Electoral Division of Durack and the state electoral district of Geraldton
Electoral district of Geraldton
Geraldton is an electoral district of the Legislative Assembly in the Australian state of Western Australia.Geraldton was one of the original 30 seats contested at the 1890 state election...
. It is part of the Houtman Abrolhos Nature Reserve, an A-class reserve
Nature reserve
A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...
managed by Western Australia's Department of Fisheries.
Geology and physiography
The basementBasement Rock
Basement or Basement Rock music was a sub-genre coined in 2006 in an article by music magazine TGR. This was first in relation to the existence of underground record label Criminal Records but more for the independent bands they represent. The roots of the sub-genre are noted to be as far back as...
of North Island is the Wallabi Limestone
Wallabi Limestone
Wallabi Limestone is the name given to the dense calcretised, limestone platform that underlies the Wallabi Group of the Houtman Abrolhos, an archipelago off the coast of Western Australia. This platform, which arises abruptly from a flat shelf, is about 40 metres thick, and is of marine biogenic...
, a dense calcretised, coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
platform that underlies the entire Wallabi Group. Arising abruptly from a flat shelf, it is about 40 m (131 ft) thick, and of Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
origin. Areas of reef that formed during the Eemian interglacial
Eemian interglacial
The Eemian was an interglacial period which began about 130,000 years ago and ended about 114,000 years ago. It was the second-to-latest interglacial period of the current Ice Age, the most recent being the Holocene which extends to the present day. The prevailing Eemian climate is believed to...
(about 125,000 years ago), when sea levels were higher than at present, are now emergent in places, and these form the basement of the group's central platform islands, namely West Wallabi Island
West Wallabi Island
West Wallabi Island is an island in the Wallabi Group of the Houtman Abrolhos, located in the Indian Ocean off the west coast of mainland Australia.-History:...
, East Wallabi Island
East Wallabi Island
East Wallabi Island is an island in the Wallabi Group of the Houtman Abrolhos, located in the Indian Ocean off the west coast of mainland Australia.-History:East Wallabi Island played an important role in the story of the Batavia shipwreck and massacre...
and North Island.
North Island's basement for the most part does not exceed 1.5 m (5 ft) in elevation. Much of it is capped by aeolianite, and nearly all of it is covered with sand, but there are some exposed outcrops. The southern margin of the island, for example, takes the form of a low cliff, which is severely undercut by the sea in many places.
There are extensive dunes of unconsolidated Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
sand along both the western and eastern sides of the island. The topography of these dunes varies with time: in 1913, Dakin recorded the dunes as being a good deal higher in the east than in the west, but in 1960 Storr found the eastern dunes to be severely eroded, apparently because of a fire that burnt much of the island's vegetation in 1935. In the centre of the island is a low plain with a sinkhole
Sinkhole
A sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline or cenote, is a natural depression or hole in the Earth's surface caused by karst processes — the chemical dissolution of carbonate rocks or suffosion processes for example in sandstone...
in its southwest corner and a small salt lake
Salt lake
A salt lake or saline lake is a landlocked body of water which has a concentration of salts and other dissolved minerals significantly higher than most lakes . In some cases, salt lakes have a higher concentration of salt than sea water, but such lakes would also be termed hypersaline lakes...
near its northern edge. The soil in the centre of the plain is shallow loam
Loam
Loam is soil composed of sand, silt, and clay in relatively even concentration . Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils...
, whereas the rim is deeper and composed largely of shell fragments.
Climate
As of 2007 the Australian Bureau of MeteorologyBureau of Meteorology
The Bureau of Meteorology is an Executive Agency of the Australian Government responsible for providing weather services to Australia and surrounding areas. It was established in 1906 under the Meteorology Act, and brought together the state meteorological services that existed before then...
has not published climatic
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
data for North Island, but an automatic weather station
Automatic weather station
An automatic weather station is an automated version of the traditional weather station, either to save human labour or to enable measurements from remote areas...
has been installed on the island since 1990, and hourly measures of precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
, air temperature, wind speed
Wind speed
Wind speed, or wind velocity, is a fundamental atmospheric rate.Wind speed affects weather forecasting, aircraft and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications....
, wind direction
Wind direction
Wind direction is reported by the direction from which it originates. For example, a northerly wind blows from the north to the south. Wind direction is usually reported in cardinal directions or in azimuth degrees...
, relative humidity
Relative humidity
Relative humidity is a term used to describe the amount of water vapor in a mixture of air and water vapor. It is defined as the partial pressure of water vapor in the air-water mixture, given as a percentage of the saturated vapor pressure under those conditions...
and atmospheric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
have been publicly available since then. This is the only weather station in the Houtman Abrolhos, so its data underlies climatic models of the island chain as a whole. Based on the data for North Island, the Houtman Abrolhos has been described as having a Mediterranean climate
Mediterranean climate
A Mediterranean climate is the climate typical of most of the lands in the Mediterranean Basin, and is a particular variety of subtropical climate...
with warm, dry summers and cooler, wet winters. Mean temperatures range from 9.3 to 19.5 °C (48.7 to 67.1 °F) in July, and from 19.1 to 32.4 °C (66.4 to 90.3 °F) in February. This is a substantially smaller range than on the mainland: the summer temperature is typically a degree cooler, while winter temperatures are a good deal warmer. This is due to the influence of the ocean, in particular the Leeuwin Current
Leeuwin Current
The Leeuwin Current is a warm ocean current which flows southwards near the western coast of Australia. It rounds Cape Leeuwin to enter the waters south of Australia where its influence extends as far as Tasmania...
.
Eighty-six percent of the island's rain falls between April and September; on average there are 89 rain days, resulting in 469 mm (18 in) of rain. The wettest month is June, when over 100 mm (4 in) typically falls. In contrast, only about 70 mm (3 in) can be expected to fall between October and March.
It is nearly always windy. During summer a high-pressure ridge lies to the south, causing persistent winds from the southeast or southwest at speeds exceeding 17 kn (33 km/h) almost half the time. During autumn and winter, the ridge moves north, increasing atmospheric pressure over the islands and creating variable winds. Winter tends to produce both the strongest gales and the most frequent periods of calm. In addition to these winds, there is daily pattern of land breezes in the morning, followed by the onset of south-westerly sea breezes in the afternoon. This pattern is caused by temperature differences between the land and the ocean; it is not as strong in the Houtman Abrolhos chain as on the mainland, but is present.
Three classes of storm have been identified in the region. Brief squalls may occur between December and April. A tropical cyclone
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
occurs in the area about once in three years, between January and April; these may generate extremely high wind speeds that are potentially destructive. During winter, extra-tropical cyclones sometimes pass south of Geraldton, generating winter gales with gusts of up to 35 m/s, the wind direction from the northwest initially, then gradually moving around to southerly.
Flora
Most of North Island is dominated by chenopod shrubs, generally less than a metre (3 ft) high. The beach vegetation is largely Spinifex longifoliusSpinifex longifolius
Spinifex longifolius, commonly known as Beach Spinifex, is a perennial grass that grows along the northern and eastern rim of the Indian Ocean.-Description:It grows as a tussock from 30 centimetres to a metre high, and up to two metres wide...
(Beach Spinifex), Salsola kali
Salsola kali
Kali soda is an annual plant that grows in arid soils and in sandy coastal soils. Its original range is Eurasian, but it has become naturalized, and even invasive, in North America, Australia, and elsewhere...
(Prickly Saltwort), Atriplex cinerea
Atriplex cinerea
Atriplex cinerea is a species of plant in the Chenopodiaceae family. It occurs in sheltered coastal areas and around salt lakes in the Australian states of Western Australia, South Australia, Tasmania, Victoria and New South Wales....
(Grey Saltbush) and naturalised Cakile maritima
Cakile maritima
Cakile maritima, the European searocket, is a common plant in the mustard family. It is widespread in Europe, especially on coastlines, and it can now be found in other areas of the world where it has been introduced. It is an inhabitant of the west and east coasts of North America, where it has...
(Sea Rocket). Stable dunes are vegetated by Atriplex paludosa
Atriplex paludosa
Atriplex paludosa, commonly known as Marsh Saltbush, is a species of saltbush endemic to Australia.-Description:It grows as an erect shrub up to a metre high...
(Marsh Saltbush), Scaevola crassifolia
Scaevola crassifolia
Scaevola crassifolia is a shrub in the family Goodeniaceae, native to Western Australia and South Australia. Common names include Cushion Fanflower, Thick-leaved Fanflower and Thick-leaved Scaevola...
(Thick-leaved Fan-flower), Olearia axillaris
Olearia axillaris
Olearia axillaris is a shrub of the Asteraceae family, found in coastal areas of Australia. Commonly known as the Coastal Daisybush, it was one of the first edible plants to be discovered by Europeans.-Description:...
(Coastal Daisy-bush), Myoporum insulare
Myoporum insulare
Myoporum insulare is a shrub or small tree which occurs on dunes and coastal cliffs in Australia. Common names include Common Boobialla, Boobialla, Native Juniper and, in Western Australia, Blueberry Tree....
(Blueberry Tree) and Exocarpos sparteus
Exocarpos sparteus
Exocarpos sparteus is an Australian endemic plant species, commonly known as the Broom Ballart or native cherry. The species is found in all states of mainland Australia.-Description:...
(Broom Ballart). Sheltered areas behind dunes support Salsola kali and Myoporum insulare and also Nitraria billardierei
Nitraria billardierei
Nitraria billardierei is a perennial salt tolerant shrub. It is often found in saline areas or areas that have been overgrazed. Nitre Bush flowers mainly in spring with small ovoid or oblong fruit that are purple, red or golden...
(Nitre Bush), the last of these being the only plant on the island to grow over m (5 ft) high. In areas where limestone is close to the surface, the vegetation consists of Pimelea microcephala
Pimelea microcephala
Pimelea microcephala is a dioecious shrub in the family Thymelaeaceae, native to Australia....
(Shrubby Rice-flower), Spyridium globulosum
Spyridium globulosum
Spyridium globulosum is a shrub in the family Rhamnaceae. It is endemic to Western Australia where it occurs on coastal dunes and in limestone areas. It grows to between 0.6 and 5 metres in height and produces white flowers between June and November in its native range....
(Basket Bush) and Acanthocarpus preissii
Acanthocarpus preissii
Acanthocarpus preissii is a rhizomatous perennial that occurs on coastal dunes in Western Australia. White flowers appear between April and May in the species native range....
.
The rim of the central plain is vegetated by a dense shrubland of Rhagodia baccata
Rhagodia baccata
Rhagodia baccata, commonly known as Berry Saltbush, is a species of shrub endemic to Western Australia.-Description:It is a spreading shrub up to two metres high, with elliptical leaves, and flowers that occur in a panicle. It bears red berries....
(Berry Saltbush), Atriplex paludosa and Threlkeldia diffusa
Threlkeldia diffusa
Threlkeldia diffusa, also known as Coast Bonefruit, is a perennial herb which occurs in coastal areas and saline flats in Australia. It is sometimes prostrate or may grow up to 0.4 metres in height. The green flowers occur between October and November in its native range....
(Coast Bonefruit). Nearer the centre, the vegetation consists of Frankenia pauciflora
Frankenia pauciflora
Frankenia pauciflora is a shrub in the Frankeniaceae family, native to southern Australia....
(Seaheath), Muellerolimon salicorniaceum and Tecticornia arbuscula
Tecticornia arbuscula
Tecticornia arbuscula ' is a species of plant in the family Amaranthaceae, native to Australia. It grows to 2 metres in height, with a spreading habit. It has succulent swollen branchlets with small leaf lobes....
(Bulli Bulli), although T. arbuscula is replaced by Tecticornia halocnemoides
Tecticornia halocnemoides
Tecticornia halocnemoides, commonly known as Shrubby Samphire or Grey Glasswort, is a species of succulent, salt tolerant plant endemic to Australia. It grows as a spreading or erect shrub up to fifty centimetres high...
(Shrubby Samphire) where the soil is shallow. The most low-lying area of the central plain, south of the salt lake, is water-logged in winter; it is vegetated by a dense mat of Sarcocornia quinqueflora
Sarcocornia quinqueflora
Sarcocornia quinqueflora, commonly known as Beaded Samphire, Bead weed or Beaded Glasswort, is a species of succulent halophytic coastal shrub...
(Beaded Samphire), Sporobolus virginicus
Sporobolus virginicus
Sporobolus virginicus, known by numerous common names including Marine Couch, Sand Couch, Coastal Rat-tail Grass, Salt Couch Grass, Saltwater Couch and Nioaka, is a coastal non-bunching tussock grass with a wide distribution.-Description:It is a perennial tussock grass from 10 to 50 centimetres in...
(Marine Couch) and Suaeda australis
Suaeda australis
Suaeda australis ' is a species of plant in the family Amaranthaceae, native to Australia. It grows to between 0.1 and 0.9 metres in height, with a speading habit and branching occurring from the base. The leaves are up to 40mm in length and are succulent, linear and flattened. They are light...
(Seablite).
The dune, limestone and salt lake vegetation communities on North Island are considered to have high conservation significance. The dune and limestone communities have high biodiversity, are highly sensitive to disturbance and regenerate slowly. The salt lake community is considered significant because of the rarity of salt lakes on offshore islands.
According to a survey published in 2001, the following vascular plants occur on North Island:
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Euchiton sphaericus Euchiton sphaericus is a herb native to Australia.-Description:It grows as an erect annual herb from 4 to 25 centimetres high, with yellow, cream or brown flowers.-Taxonomy:... Euphorbia tannensis Euphorbia tannensis is a species of herb or shrub native to Australia and some Pacific islands.-Description:It grows as an erect annual or perennial herb or shrub, from 10 centimetres to a metre in height, with green or yellow flowers... Exocarpos sparteus Exocarpos sparteus is an Australian endemic plant species, commonly known as the Broom Ballart or native cherry. The species is found in all states of mainland Australia.-Description:... (Broom Ballart) Ficinia nodosa Ficinia nodosa is a rhizomatous perennial in the family Cyperaceae, native to Australia and New Zealand. It grows to between 15 and 100 cm in height.... (Knotted Club Rush) Frankenia pauciflora Frankenia pauciflora is a shrub in the Frankeniaceae family, native to southern Australia.... (Seaheath) Grevillea argyrophylla Grevillea argyrophylla is a shrub in the family Proteaceae. It is endemic to south-western Western Australia.... (Silvery-leaved Grevillea) Helichrysum luteoalbum Helichrysum luteoalbum, commonly known as Jersey Cudweed or Weedy Cudweed, is a cosmopolitan weed.-Description:It grows as an erect herb up to 70 centimetres high, branching from the base... (Jersey Cudweed) Hordeum murinum subsp. leporinum Hordeum murinum subsp. leporinum is a subspecies of Hordeum murinum .Its common names include hare barley, mouse barley, and barley grass.-Taxonomy:... (Barley Grass) (naturalised) Hornungia procumbens Hornungia procumbens is a species of herb native to the temperate zone of the northern hemisphere. Common names include Oval Purse, Slenderweed and Prostrate Hutchinsia.-Description:It is an annual herb with white flowers... (Oval Purse) (naturalised) Juncus bufonius Juncus bufonius, known commonly as toad rush, is a common species of rush found worldwide. It grows in moist and muddy places and is considered a weed in many areas. This is an annual monocot that is quite variable in appearance. It is sometimes described as a complex of variants labeled with one... (Toad Rush) (naturalised) Malva parviflora Malva parviflora is an annual or perennial herb that is native to Northern Africa, Europe and Asia and is widely naturalised elsewhere. Common names include cheeseweed, cheeseweed mallow, Egyptian mallow, least mallow, little mallow, mallow, marshmallow, small-flowered mallow, small-flowered... (Marshmallow) (naturalised) Melilotus indicus Melilotus indicus, sometimes incorrectly written Melilotus indica, is a yellow-flowered herb native to northern Africa, Europe and Asia, but naturalized throughout the rest of the world.... (naturalised) Mesembryanthemum crystallinum Mesembryanthemum crystallinum is a prostrate succulent plant that is native to Africa, Western Asia and Europe. The plant is covered with large, glistening bladder cells, reflected in its common names of Common Ice Plant, Crystalline Iceplant or Iceplant.-Uses:Its leaves are edible, as with some... (Iceplant) (naturalised) Myoporum insulare Myoporum insulare is a shrub or small tree which occurs on dunes and coastal cliffs in Australia. Common names include Common Boobialla, Boobialla, Native Juniper and, in Western Australia, Blueberry Tree.... (Blueberry Tree) Nicotiana occidentalis subsp. hesperis Nicotiana occidentalis subsp. hesperis is a short-lived herb native to Australia.-Description:It grows as an erect annual or short-lived perennial herb, from ten to 50 centimetres high, with white flowers.-Taxonomy:... (Native Tobacco) Nitraria billardierei Nitraria billardierei is a perennial salt tolerant shrub. It is often found in saline areas or areas that have been overgrazed. Nitre Bush flowers mainly in spring with small ovoid or oblong fruit that are purple, red or golden... (Nitre Bush) Olearia axillaris Olearia axillaris is a shrub of the Asteraceae family, found in coastal areas of Australia. Commonly known as the Coastal Daisybush, it was one of the first edible plants to be discovered by Europeans.-Description:... (Coastal Daisy Bush) Parapholis incurva Parapholis incurva is a species of grass native to Europe, Asia and northern Africa, and widely naturalised elsewhere. Common names include Coast Barbgrass, Curved Sea Hard Grass, Sickle Grass, Curved Sicklegrass and Curved Parapholis.-Taxonomy:It was first published as Aegilops incurva by Carl... (Coast Barbgrass) (naturalised) Parietaria debilis Parietaria debilis, commonly known as Pellitory or Native Pellitory, is a herb native to Australia and New Zealand.-Description:It grows as an annual herb from 7 to 40 centimetres in height, with green or white flowers... (Pellitory) Phalaris minor Phalaris minor is a species of grass native to northern Africa, Europe and Asia, and widely naturalised elsewhere.Common names include little seed canary grass, small-seeded canary grass, small canary grass and lesser canary grass.... (Lesser Canary Grass) (naturalised) Pimelea microcephala Pimelea microcephala is a dioecious shrub in the family Thymelaeaceae, native to Australia.... (Shrubby Riceflower) Plantago debilis Plantago debilis is a species of herb native to Australia. Common names include Shade Plantain and Weak Plantain.-Description:... Podotheca angustifolia Podotheca angustifolia, commonly known as Sticky Longheads, is a species of herb native to Australia.-Description:An annual herb with yellow flowers, P. angustifolia grows in a range of habits, from trailing along the ground to erect; when erect if can reach up to 30 centimetres in height, but... (Sticky Longheads) Rhagodia baccata Rhagodia baccata, commonly known as Berry Saltbush, is a species of shrub endemic to Western Australia.-Description:It is a spreading shrub up to two metres high, with elliptical leaves, and flowers that occur in a panicle. It bears red berries.... (Berry Saltbush) Rhagodia latifolia Rhagodia latifolia is a species of shrub endemic to midwest Western Australia.-Description:It grows as a shrub from 40 centimetres to two metres high, leathery, elliptical leaves, and panicles of green flowers.-Taxonomy:... |
Rostraria cristata Rostraria cristata is an annual grass species which is native to Eurasia and widely naturalised elsewhere.... (naturalised) Salsola kali Kali soda is an annual plant that grows in arid soils and in sandy coastal soils. Its original range is Eurasian, but it has become naturalized, and even invasive, in North America, Australia, and elsewhere... (Prickly Saltwort) (naturalised) Sarcocornia quinqueflora Sarcocornia quinqueflora, commonly known as Beaded Samphire, Bead weed or Beaded Glasswort, is a species of succulent halophytic coastal shrub... (Beaded Samphire) Scaevola crassifolia Scaevola crassifolia is a shrub in the family Goodeniaceae, native to Western Australia and South Australia. Common names include Cushion Fanflower, Thick-leaved Fanflower and Thick-leaved Scaevola... (Thick-leaved Fan-flower) Schenkia australis Schenkia australis is a species of annual herb in the Gentianaceae family. It is endemic to Australia.-Description:S. australis grows as an annual, or rarely biannual, herb, from 2 to 30 centimetres high... (naturalised) Senecio glossanthus Senecio glossanthus is an annual herb native to Australia. In Western Australia it is commonly known as Slender Groundsel.-Description:... (Slender Groundsel) Senecio pinnatifolius Senecio pinnatifolius is a species of herb native to Australia. Common names include Coast Groundsel.-Taxonomy:The name Senecio pinnatifolius was first published by Achille Richard in 1834, but it was not immediately taken up. Instead, the species was long treated as the Australian component of... Setaria dielsii Setaria dielsii, commonly known as Diels' Pigeon Grass, is a species of grass native to Australia.-Description:It is an annual grass that grows in tufts from 20 to 130 centimetres high. It has green flowers that occur in an open panicle.... (Diels' Pigeon Grass) Sonchus oleraceus Sonchus oleraceus is a medicinal plant native to Asia and Europe, which is nutritious food for humans and most livestock.- Nutritive qualities :The common name Sow thistle refers to its... (Common Sow Thistle) (naturalised) Spergularia rubra Spergularia rubra, the red sand spurrey or red sandspurry, is a plant species in the pink family. It is native to Europe and Asia, and it is present on other continents, including North and South America and Australia, as an introduced species and in many areas a common weed. It grows in a wide... (Sand Spurry) (naturalised) Spinifex longifolius Spinifex longifolius, commonly known as Beach Spinifex, is a perennial grass that grows along the northern and eastern rim of the Indian Ocean.-Description:It grows as a tussock from 30 centimetres to a metre high, and up to two metres wide... (Beach Spinifex) Sporobolus virginicus Sporobolus virginicus, known by numerous common names including Marine Couch, Sand Couch, Coastal Rat-tail Grass, Salt Couch Grass, Saltwater Couch and Nioaka, is a coastal non-bunching tussock grass with a wide distribution.-Description:It is a perennial tussock grass from 10 to 50 centimetres in... (Marine Couch) Spyridium globulosum Spyridium globulosum is a shrub in the family Rhamnaceae. It is endemic to Western Australia where it occurs on coastal dunes and in limestone areas. It grows to between 0.6 and 5 metres in height and produces white flowers between June and November in its native range.... (Basket Bush) Stackhousia Stackhousia is a genus of annual and perennial plants in the family Celastraceae that are native to Australia, New Zealand, Malesia and Micronesia... sp. Suaeda australis Suaeda australis ' is a species of plant in the family Amaranthaceae, native to Australia. It grows to between 0.1 and 0.9 metres in height, with a speading habit and branching occurring from the base. The leaves are up to 40mm in length and are succulent, linear and flattened. They are light... (Seablite) Tecticornia arbuscula Tecticornia arbuscula ' is a species of plant in the family Amaranthaceae, native to Australia. It grows to 2 metres in height, with a spreading habit. It has succulent swollen branchlets with small leaf lobes.... Tecticornia halocnemoides Tecticornia halocnemoides, commonly known as Shrubby Samphire or Grey Glasswort, is a species of succulent, salt tolerant plant endemic to Australia. It grows as a spreading or erect shrub up to fifty centimetres high... (Shrubby Samphire) Threlkeldia diffusa Threlkeldia diffusa, also known as Coast Bonefruit, is a perennial herb which occurs in coastal areas and saline flats in Australia. It is sometimes prostrate or may grow up to 0.4 metres in height. The green flowers occur between October and November in its native range.... (Coast Bonefruit) Thysanotus patersonii Thysanotus patersonii is a twining perennial herb which is endemic to Australia.It is leafless and grows to between 0.15 and 0.5 metres in height and produces purple flowers between July and November in its native range.... Trichodesma zeylanicum Trichodesma zeylanicum, commonly known as Camel Bush or Cattle Bush, is a herb or shrub native to Australia.-Description:It grows as an erect herb or shrub up to two metres high, with a well-developed taproot. Flowers are blue, or rarely white.-Taxonomy:This species was first published as Borago... (Camel Bush) Triglochin mucronata Triglochin mucronata is a salt-tolerant herb native to Australia.-Description:It grows as an annual herb that sprawls along the ground, reaching a height of no more than 22 centimetres. It has green flowers.-Taxonomy:... Triglochin trichophora Triglochin trichophora is an annual herb native to Australia.-Taxonomy:This species was published in 1848 by Christian Gottfried Daniel Nees von Esenbeck. It is had an uneventful taxonomic history.-Distribution and habitat:... Vulpia myuros Vulpia myuros, or Rat’s-tail Fescue, is an annual grass species of the genus Vulpia. It was probably originally native to Eurasia, but it can now be found nearly worldwide as a naturalized species.... (Rat's Tail Fescue) (naturalised) Wurmbea monantha Wurmbea monantha is a perennial herb that is native to Western Australia. The white to pink flowers are produced between July and September in its native range.... Zygophyllum simile Zygophyllum simile is a succulent annual herb native to Australia.-Description:It grows as a prostrate or erect annual herb, branching from the base and reaching a height of from four to 60 centimeters... |
Mammals
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...
(Neophoca cinerea) occasionally hauls out
Hauling-out
Hauling-out is the behaviour associated with pinnipeds , of temporarily leaving the water between periods of foraging activity for sites on land or ice...
on the island's beaches, and it has been suggested that the island once had a native population of Tammar Wallaby
Tammar Wallaby
The Tammar Wallaby , also known as the Dama Wallaby or Darma Wallaby, is a small member of the kangaroo family and is the model species for research on kangaroos and marsupials. It is found on offshore islands on the South Australian and Western Australian coast...
(Macropus eugenii).
Stokes explicitly stated the Tammar Wallaby to be absent from North Island in 1840, and it was not recorded by the Percy Sladen Trust Expedition in 1913. It was apparently introduced to the island in the 1920s, as early fishermen reported seeing it between 1928 and 1930. This introduction failed, possibly due to overgrazing. The species was not found by Serventy during his 1945 visit, nor by Storr in 1959, but the latter found plenty of remains, mostly mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
s. Storr interpreted these remains as predating the 1920s introduction, suggesting that a native population of Tammars became extinct on the island before 1840. Albert Russell Main agreed, but the theory has not been accepted by later researchers.
Morelia spilota imbricata
Morelia spilota imbricata is a large snake found in southern regions of Western Australia and western South Australia. A member of the python family, it is commonly known as the Southern Carpet Python.-Description:...
); the availability of additional food and water from the fishers' huts, which are occupied during the harshest time of the year; and the presence of the air strip, which apparently provides additional food for them. By the 2000s, there were over 450 Tammar Wallabies on the island. The wallabies overgrazed and ringbarked
Girdling
Girdling, also called ring barking or ring-barking, is the complete removal of a strip of bark from around the entire circumference of either a branch or trunk of a woody plant. Girdling results in the death of wood tissues beyond the damage...
the native vegetation, particularly the area burnt in 1935, thus reducing vegetation cover and causing a serious decline in populations of some plant species. In 2003, island residents asked the Department of Conservation and Land Management (CALM; now the Department of Environment and Conservation) for help in managing the issue. CALM staff visited the island in April and May of that year and produced a report recommending an investigation into controlling population levels by the use of implant
Implant (medicine)
An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...
ed contraceptives. Exploration of this option began in 2005, but in July 2007 the research was discontinued. Around 60 wallabies were removed to educational institutions for research purposes, and culling began. By February 2008, the wallaby population had been reduced to around 25 individuals.
The only other mammal known to occur on the island is the naturalised House Mouse
House mouse
The house mouse is a small rodent, a mouse, one of the most numerous species of the genus Mus.As a wild animal the house mouse mainly lives associated with humans, causing damage to crops and stored food....
(Mus Musculus). Eight European Rabbit
European Rabbit
The European Rabbit or Common Rabbit is a species of rabbit native to south west Europe and north west Africa . It has been widely introduced elsewhere often with devastating effects on local biodiversity...
s (Oryctolagus cuniculus) were introduced in 1934, and were found to be "exceedingly numerous" by 1945, but by 1960 they were extinct, apparently from predation by feral cat
Feral cat
A feral cat is a descendant of a domesticated cat that has returned to the wild. It is distinguished from a stray cat, which is a pet cat that has been lost or abandoned, while feral cats are born in the wild; the offspring of a stray cat can be considered feral if born in the wild.In many parts of...
s. Neither rabbits nor cats are now reported as naturalised on the island.
Reptiles
Reptiles recorded on North Island include Binoe's Prickly Gecko (Heteronotia binoei), the geckoGecko
Geckos are lizards belonging to the infraorder Gekkota, found in warm climates throughout the world. They range from 1.6 cm to 60 cm....
Christinus marmoratus, the Jew Lizard (Pogona barbata), King's Skink (Egernia kingii), the Western Limestone Ctenotus
Western limestone ctenotus
The Western Limestone Ctenotus is a species of skink native to coastal areas of south west Western Australia. It is found amongst heath on coastal dunes, and in open woodland on the Swan Coastal Plain. It is generally restricted to areas with limestone.It is quite large for a Ctenotus...
(Ctenotus australis), the Western Worm Lerista
Western worm lerista
The western worm lerista is a species of skink native to coastal areas of southwest and midwestWestern Australia. It is found amongst heath and woodlands on coastal dunes....
(Lerista praepedita), the Common Dwarf Skink
Common dwarf skink
Menetia greyii, commonly known as the Common dwarf skink, is a species of lizard endemic to mainland Australia. One of Australia's most widespread and abundant lizards, it is occurs in all parts of the mainland except coastal areas in the south-east, and Cape York Peninsula...
(Menetia greyii), and the Abrolhos Bearded Dragon (Pogona minor minima). The Carpet Python was reported as present on the island in very low numbers before 1960, but it has never been observed there by naturalists, and is now absent.
The Green Turtle (Chelonia mydas) has been observed in large numbers near the shore, and it has been claimed that they breed on the island, but this has never been verified. If it is true, then North Island would be the species' most southerly breeding site in Western Australia.
Birds
The birds most often mentioned in relation to North Island are the Abrolhos Painted Button-quailAbrolhos Painted Button-quail
The Abrolhos Painted Button-quail is a subspecies of the Painted Buttonquail endemic to the Houtman Abrolhos. It is common on North Island, and also occurs on other islands of the Wallabi Group, namely East Wallabi, West Wallabi, Seagull and Pigeon Islands...
(Turnix varius scintillans), a rare subspecies of the widespread Painted Button-quail (Turnix varius) known only from the Wallabi Group and protected under the Wildlife Conservation Act 1950
Wildlife Conservation Act 1950
The Wildlife Conservation Act 1950 is an act of the Western Australian Parliament that provides the statute relating to conservation and legal protection of flora and fauna....
; and the Brush Bronzewing
Brush Bronzewing
The Brush Bronzewing is a species of bird in the pigeon family Columbidae.It is endemic to Australia.Its natural habitat is subtropical or tropical dry forests.-References:...
(Phaps elegans), one of the most common birds on North Island, the mainland populations of which are decreasing.
Other birds known to breed on North Island include the Osprey
Osprey
The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...
(Pandion haliaetus cristatus), Greater Crested Tern
Greater Crested Tern
The Greater Crested Tern , also called Crested Tern or Swift Tern, is a seabird in the tern family which nests in dense colonies on coastlines and islands in the tropical and subtropical Old World...
(Thalasseus bergii), Caspian Tern
Caspian Tern
The Caspian Tern is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no subspecies accepted either...
(Hydroprogne caspia), Silver Gull
Silver Gull
The Silver Gull also known simply as "seagull" in Australia, is the most common gull seen in Australia. It has been found throughout the continent, but particularly coastal areas. The South African Hartlaub's Gull and the New Zealand Red-billed Gull The Silver Gull (Chroicocephalus...
(Chroicocephalus novaehollandiae novaehollandiae), and Welcome Swallow
Welcome Swallow
The Welcome Swallow is a small passerine bird in the swallow family.It is a species native to Australia and nearby islands, but not until recently to New Zealand, which has been colonised in the last half century...
(Hirunda neoxena). Birds commonly recorded as resident on the island but not recorded as breeding there include the Reef Heron (Egretta sacra), White-bellied Sea Eagle
White-bellied Sea Eagle
The White-bellied Sea Eagle , also known as the White-breasted Sea Eagle, is a large diurnal bird of prey in the family Accipitridae. Originally described by Johann Friedrich Gmelin in 1788, it is closely related to Sanford's Sea Eagle of the Solomon Islands, and the two are considered a superspecies...
(Haliaeetus leucogaster), Red-capped Plover
Red-capped Plover
The Red-capped Plover , also known as the Red-capped Dotterel, is a small plover. It breeds in Australia. The species is closely related to the Kentish Plover, Javan Plover and White-fronted Plover.-Description:Red-capped Plovers have white underparts and forehead...
(Charadrius ruficapillus), Fairy Tern
Fairy Tern
The Fairy Tern is a small tern which occurs in the southwestern Pacific.There are three subspecies:* Australian Fairy Tern, Sterna nereis nereis - breeds in Australia...
(Sterna nereis nereis), Australasian Pipit
Australasian Pipit
The Australasian Pipit is a fairly small passerine bird of open country in Australia, New Zealand and New Guinea. It belongs to the pipit genus Anthus in the family Motacillidae....
(Antus novaseelandiae australis) and Western Silvereye
Western Silvereye
The Western Silvereye is a small greenish bird in the Zosteropidae or White-eye family. It is a subspecies of the Silvereye that occurs in Western Australia and South Australia. It is sometimes called the White-eye or Greenie...
(Zosterops lateralis chloronotus). The Sooty Oystercatcher
Sooty Oystercatcher
The Sooty Oystercatcher, Haematopus fuliginosus, is a species of oystercatcher. It is a wading bird native to Australia and commonly found on its coastline. It prefers rocky coastlines, but will occasionally live in estuaries....
(Haematopus fuliginosus fuliginosus) and White-backed Swallow
White-backed Swallow
The White-backed Swallow is a bird in the Hirundinidae family endemic to Australia. It is monotypic within the genus Cheramoeca.-References:* BirdLife International 2004. . Downloaded on 25 July 2007....
(Cheramoeca leucosterna) have also rarely been observed as resident on the island.
The most common visitors to the island are the Bar-tailed Godwit
Bar-tailed Godwit
The Bar-tailed Godwit is a large wader in the family Scolopacidae, which breeds on Arctic coasts and tundra mainly in the Old World, and winters on coasts in temperate and tropical regions of the Old World...
(Limosa lapponica baueri), Grey-tailed Tattler
Grey-tailed Tattler
The Grey-tailed Tattler, Tringa brevipes , is a small shorebird.- Description :...
(Tringa brevipes), Ruddy Turnstone
Ruddy Turnstone
The Ruddy Turnstone is a small wading bird, one of two species of turnstone in the genus Arenaria. It is now classified in the sandpiper family Scolopacidae but was formerly sometimes placed in the plover family Charadriidae...
(Arenaria interpres interpres), Red-necked Stint
Red-necked Stint
The Red-necked Stint is a small migratory wader.- Description :These birds are among the smallest of waders, very similar to the Little Stint, Calidris minuta, with which they were once considered conspecific...
(Calidris ruficollis) and Curlew Sandpiper
Curlew Sandpiper
The Curlew Sandpiper is a small wader that breeds on the tundra of Arctic Siberia. It is strongly migratory, wintering mainly in Africa, but also in south and southeast Asia and in Australasia...
(Calidris ferruginea). Other observed visitors include the Great Cormorant
Great Cormorant
The Great Cormorant , known as the Great Black Cormorant across the Northern Hemisphere, the Black Cormorant in Australia and the Black Shag further south in New Zealand, is a widespread member of the cormorant family of seabirds...
(Phalacrocorax carbo novaehollandiae), Nankeen Kestrel
Nankeen Kestrel
The Australian Kestrel or Nankeen Kestrel is one of the smallest falcons, and unlike many, does not rely on speed to catch its prey. Instead, it simply perches in an exposed position, but it also has a distinctive technique of hovering over crop and grasslands...
(Falco cenchroides cenchroides), Banded Lapwing
Banded Lapwing
The Banded Lapwing is a small to medium sized wader which belongs to the plover family. It is found over most of Australia and Tasmania though is absent from the northern third of the continent....
(Vanellus tricolor), Greater Sand Plover
Greater Sand Plover
The Greater Sand Plover, Charadrius leschenaultii, is a small wader in the plover family of birds. The spelling is commonly given as "Greater sandplover", but the official British Ornithologists' Union spelling is "Greater sand plover"....
(Charadrius leschenaultii), Whimbrel
Whimbrel
The Whimbrel Numenius phaeopus, is a wader in the large family Scolopacidae. It is one of the mostwidespread of the curlews, breeding across much of subarctic North America, Europe and Asia as far south as Scotland....
(Numenius phaeopus variegatus), Greenshank
Greenshank
The Common Greenshank is a wader in the large family Scolopacidae, the typical waders. Its closest relative is the Greater Yellowlegs, together with which and the Spotted Redshank it forms a close-knit group...
(Tringa nebularia), Sanderling
Sanderling
The Sanderling is a small wader. It is a circumpolar Arctic breeder, and is a long-distance migrant, wintering south to South America, South Europe, Africa, and Australia...
(Calidris alba), Willie Wagtail
Willie Wagtail
The Willie Wagtail is a passerine bird native to Australia, New Guinea, the Solomon Islands, the Bismarck Archipelago, and eastern Indonesia. It is a common and familiar bird throughout much of its range, living in most habitats apart from thick forest...
(Rhipidura leucophrys leucophrys) and Brown Songlark
Brown Songlark
The Brown Songlark , also Australian Songlark, is a small passerine bird found throughout much of Australia. A member of the Old World Warbler family, the species is notable for sexual size dimorphism, among the most pronounced in any bird...
(Cincloramphus cruralis).
North Island is part of the Houtman Abrolhos Important Bird Area
Important Bird Area
An Important Bird Area is an area recognized as being globally important habitat for the conservation of bird populations. Currently there are about 10,000 IBAs worldwide. The program was developed and sites are identified by BirdLife International...
, 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 importance for supporting large numbers of breeding seabirds.
Human uses
The entire Houtman Abrolhos is protected by an A-class nature reserveNature reserve
A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...
that is wholly vested in Western Australia's Minister for Fisheries for purposes of "Conservation of Flora and Fauna, Tourism, and for Purposes Associated with the Fishing Industry".
Fishing industry
North Island's primary human use is as a seasonal camp for Western Rock Lobster fishers. During lobster season, which runs from 15 March to 30 June, North Island's camp is occupied by about 130 fishers. The camp is serviced by a carrier boat, the North Islander, which visits the island every three days, bringing supplies and taking out the catch and any domestic waste.Conservation
North Island is considered to have high conservation value with respect to its populations of Brush Bronzewing and Abrolhos Painted Button-quail, and its dune, limestone and salt lake vegetation communities. The potential existence of historically significant artefacts on Record Hill, namely the bottle left by Wickham and Stokes in 1840, has not been assessed.A 514 ha (1,270 acre) area of reef immediately south of North Island is designated a Reef Observation Area (ROA). Fishing is prohibited in this area, except for the use of lobster pots. One of four ROAs in the Houtman Abrolhos, these protected areas are intended to help conserve species of territorial fish that are fished elsewhere, and to provide divers with the opportunity to observe large populations that are not frightened by their approach.