The Lord Howe Island skink (''Oligosoma lichenigerum'') is a part of the native Australian reptiles’ classification. The Lord Howe Island

Skink Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. ...

is a species of skink in the family Scincidae, located on Australia's

Norfolk Island Norfolk Island (, ; Norfuk: ''Norf'k Ailen'') is an external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia, directly east of Australia's Evans Head and about from Lord Howe Island. Together wit ...

and

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland Po ...

. The Lord Howe Island skink population is uncommon to be found on Lord Howe island, however the majority of their population is located on the Norfolk Island complex.This skink is metallic bronze in colour and has flecks for defining features. It can grow up to 8cm in length, making them medium in size. Its taxonomy is diverse, the skink is a part of the Scincidae family, Oligosoma genus. This skink population is protected and considered vulnerable under the Environment Protection and biodiversity conservation act 1999.

Ecology

Description

The Lord Howe Island skink (''Oligosoma lichenigera)'' is metallic bronze or olive in colour on the top. It has brown flecks or streaks that are aligned longitudinally along the body, often with brown spots on the head. It has a pale golden stripe that extends from above the eye to the tail, which is its distinguishing feature. The upper body usually has pale spots, with the throat been a grey/white colour with dark grey-brown flecks and pale/dark brown limb depending on the size and age of the Lord Howe Island Skink. It can grow up to 8cm in length, making them medium in size for this type of skink. Its life span is currently unknown; however research suggests that the larger skinks can live up to 10 years.

Other names

The Lord Howe Island Skink (Oligosoma lichenigera) has previously been referred to by other names. These names include Cyclodina lichenigera, ''Leiolopisma lichenigerum, Mocoa lichenigera'' and ''Pseudemoia lichenigera'' and can interchange between academic articles.

Diet

Lord Howe island skinks are said to feed on

beetles Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describe ...

spiders Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species di ...

moths Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

ants Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Creta ...

and other

invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...

amongst the

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...

as it is in abundance on both Norfolk Island and Lord Howe Island, as it is easy for the skinks to obtain. From research it is also believed that the Lord Howe Island Skink feeds on

tern Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...

eggs that they have pushed down a hill and cracked open to feed on.

Distribution and habitat

The Lord Howe Island skink can be found on both Lord Howe Island and the Norfolk Island complex. The Lord Howe island skink is considered native to both of these islands. As both Islands are isolated from the mainland of Australia, this has enabled the Lord Howe Island skink population to grow. The Lord Howe Island skink is however uncommon to be found on Lord Howe island and the majority of their population is located on the Norfolk Island complex, specifically on Phillip

Island An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An isla ...

, which is an island that is located just off the main Norfolk Island complex.They can be found in a wide range of

habitats In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

, ranging from

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

grasslands A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge (Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur nat ...

. They are often found under and amongst

boulders In geology, a boulder (or rarely bowlder) is a rock fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In c ...

and rocks. They can also shelter during the day under rocks, in cavities on boulder beaches, in tunnels and holes in rocks, and in crevices in trees. This native skink (Oligosoma lichenigera) is occasionally diurnal, meaning active during the day but it is primarily crepuscular/

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, meaning that it is more active during the night and sleeps during the day.

Reproduction

Not much is known about the reproduction of the Lord Howe Island Skink. They lay a clutch of around 1-3 eggs per reproduction cycle and have an incubation of around 68 days.

Status and conservation

The Lord Howe Island skink are a species that is listed as Vulnerable under the

Environment Protection and biodiversity conservation act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cult ...

. However, the Lord Howe island skinks species is estimated to have populations on both Norfolk Island and Lord Howe island that are large and secure. To try and preserve the Lord Howe Island skink population the

Australian government The Australian Government, also known as the Commonwealth Government, is the national government of Australia, a federal parliamentary constitutional monarchy. Like other Westminster-style systems of government, the Australian Governmen ...

has put in measures to try and stop the decrease of the population to try and get the skink off the vulnerable list.

Measures to help get the Lord Howe Island Skink of the vulnerable list

* Control and eradication of introduced rodents, such as

rabbits Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit sp ...

and non-native geckoes. * Establish rodent baiting stations on key offshore islands to prevent establishment of rodents and the transfer of them onto Norfolk and Lord Howe Island. * Protect habitat from disturbance, particularly from

humans" \n\n\n\n\nThe robots exclusion standard, also known as the robots exclusion protocol or simply robots.txt, is a standard used by websites to indicate to visiting web crawlers and other web robots which portions of the site they are allowed to visi ...

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...

and introduced animal species to these islands. * Continue vegetation regeneration program, providing more protected and safer areas for the skink. * Implement and monitor a

quarantine A quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been ...

plan to prevent any diseases that may be harmful to the skink. * Monitor the status of populations and note if there is an increase. * Investigate the impacts of the introduced Grass Skink on the food resources of the Lord Howe Island Skink. * Research into

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overl ...

and

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar work ...

of the species to provide information to assist in its conservation.

Threats

There are a few threats that can shorten the life span of the Lord Howe Island skink.

Rats Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), '' Bandicota'' (bandicoot ...

preying upon this species is the main reasons for the population decline on the main islands of the Norfolk and Lord Howe Island complexes. As the Lord Howe Island skink is endemic to the oceanic islands of Lord Howe island and Norfolk Island complexes it is impossible to find them located anywhere else. The populations of the Lord Howe Island skink underwent major declines on the inhabited main Lord Howe Island following the introduction of R. rattus (a species of black rats) from a

shipwreck A shipwreck is the wreckage of a ship that is located either beached on land or sunken to the bottom of a body of water. Shipwrecking may be intentional or unintentional. Angela Croome reported in January 1999 that there were approximately ...

in 1927. Although the skink remains abundant on several offshore islets that remain rat-free there is limited population on the main islands due to the rat population. On Norfolk Island, the introduction of the

Polynesian Rat The Polynesian rat, Pacific rat or little rat (''Rattus exulans''), known to the Māori as ''kiore'', is the third most widespread species of rat in the world behind the brown rat and black rat. The Polynesian rat originated in Southeast Asia, a ...

(R. exulans) by Polynesian visitors led to the

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the Endling, last individual of the species, although the Functional ext ...

of the Lord Howe Island skink on the main island, however the skink is abundant and secure on the largest of the offshore islands (Phillip Island). In the past it was recorded that

cats The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members o ...

would also prey on the Lord Howe Island Skink, hence why the population in listed as vulnerable. However no cats remain on Lord Howe Island, so they are no longer a threat and the population is increasing. Another threat is the introduced skink ''

lampropholis delicata ''Lampropholis delicata'', the delicate skink, dark-flecked garden sun skink, garden skink, delicate garden skink, rainbow skink or plague skink, or the metallic skink is native to Australia and invasive in New Zealand and Hawaii where it is com ...

'' which arrived on Lord Howe Island and Norfolk Island in the early 1990s and is said to compete with the Lord Howe Island skink for food.

References

Skinks of Australia Fauna of Lord Howe Island Oligosoma Vulnerable fauna of Australia Reptiles described in 1874 Taxa named by Arthur William Edgar O'Shaughnessy Fauna of Norfolk Island Taxonomy articles created by Polbot {{Lygosominae-stub