The jewelled gecko (''Naultinus gemmeus'') is a threatened

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Diplodactylidae The Diplodactylidae are a Family (biology), family in the suborder Gekkota (geckos), with over 150 species in 25 Genus, genera. These geckos occur in Australia, New Zealand, and New Caledonia. Diplodactylids are the most ecologically diverse and ...

. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the South Island of

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. Subgroups or populations of the jewelled gecko living in

Otago Otago (, ; ) is a regions of New Zealand, region of New Zealand located in the southern half of the South Island and administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local go ...

Canterbury Canterbury (, ) is a City status in the United Kingdom, city and UNESCO World Heritage Site, in the county of Kent, England; it was a county borough until 1974. It lies on the River Stour, Kent, River Stour. The city has a mild oceanic climat ...

, and Southland can be distinguished by their colour and marking. Male Canterbury jewelled geckos tend to be grey or brown with yellow, purple and white rows of stripes or diamonds. Otago jewelled gecko populations are often green with yellow and white markings, and Southland jewelled geckos are usually solid green. The jewelled gecko eats a wide variety of insects and moths. It also eats berries and, more rarely, nectar. The jewelled gecko and other New Zealand geckos are highly protected and it is illegal to capture or disturb them. The jewelled gecko is often targeted by wildlife smugglers.

Identification

''Naultinus gemmeus'' has a bright to olive green body with either stripes or a pattern of diamonds on its back, a pattern which has given the species its common name, and is an important identifying feature. Colours often seen in the stripes or diamond shapes are white, pale green, or yellow. Those colours are often outlined by black or dark brown. The underbelly is usually a pale greenish yellow or grey and can sometimes have stripes or streaks too. There appear to be some differences in looks between the Otago and Canterbury subgroups of the jewelled gecko, as well as between the males and females. For both the Otago and Canterbury subgroups it seems that the females are more likely to have a jewelled pattern, while the males have stripes or no pattern. For the Otago subgroup the mouth of the jewelled gecko typically has a lining of deep blue colour and a blackish tongue, whilst the Canterbury subgroup have a mouth lining of pinkish colour and a pink or orange tongue. The eye colour ranges from brown to olive colored. The jewelled gecko can get to a total length of with the body usually measuring about from snout tip to anus (snout-to-vent length, abbreviated SVL). It can also weigh up to 15 grams (.53 oz) and has a very long life span lasting at least 40 years.

Conservation status

In 2012 the

Department of Conservation Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

reclassified the jewelled gecko as "At Risk" under the

New Zealand Threat Classification System The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had s ...

. It was judged as meeting the criteria for "At Risk" threat status as a result of it having a low to high ongoing or predicted decline. The jewelled gecko has a status of "Endangered" on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

, caused by several threats such as

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, degrading and fragmenting through grazing, herbicides and burning, as well as introduced predators.

Geographic Distribution

The jewelled gecko is a native species of the South Island of New Zealand. It is found only on the southeast of the South Island. More precisely the main population is found in Canterbury and Otago. Other populations have been found in the area between Canterbury and Otago, but those populations as well as the habitats are small, isolated and fragmented. The species has undergone a decline in population in recent years, and in 2008 was considered "Near Threatened" by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

Habitat

The preferred

habitat In ecology, habitat refers to the array of resources, 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 manifestation of its ...

s of the jewelled gecko are diverse woody vegetation, drylands and shrublands. It needs shelter from cold and fires in the landscape, and is therefore dependent on woody forest vegetation. The jewelled gecko is an

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

, diurnal species, which means it lives in trees and is active during the day. It can live in a wide range of tree and shrub species, like

mānuka Mānuka (; ''Leptospermum scoparium'') is a species of flowering plant in the myrtle family (biology), family Myrtaceae, native to New Zealand (including the Chatham Islands) and south-east Australia. Bees produce mānuka honey from its necta ...

beech Beech (genus ''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to subtropical (accessory forest element) and temperate (as dominant element of Mesophyte, mesophytic forests) Eurasia and North America. There are 14 accepted ...

and tūmatakuru. Rocky outcrops and boulder fields also can be suitable habitat for easy escapes from predators.

Lifecycle

The jewelled gecko is

viviparous In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juve ...

. Females typically give birth in autumn, usually a little earlier for Canterbury individuals than the Otago ones. Reproduction happens annually, and pregnancy lasts about seven months. The reproductive cycle of the jewelled gecko consists of

vitellogenesis Vitellogenesis is the process of yolk protein formation in the oocytes during sexual maturation. The term ''vitellogenesis'' comes from the Latin language, Latin ''vitellus'' ("egg yolk"). Yolk proteins, such as lipovitellin and phosvitin, provid ...

, ovulation and pregnancy, with vitellogenesis starting in autumn after birth and ovulation happening during spring. Each female gives birth to one or two juveniles. The lifespan of ''Naultinus gemmeus'' is unknown. It is thought to live for over 30 years when predation and habitat fragmentation aren't issues, based on the lifespan of other gecko species in the area. Although most geckos endemic to New Zealand are slow growing and can take 2–8 years to reach maturity, the jewelled gecko takes 4 years to reach maturity. Once reaching maturity it gives birth to one to two young each year, and like other endemic New Zealand geckos, it gives birth to live young and doesn't lay eggs. Research has shown that there is a clear seasonal pattern of reproductive activity, ovulation starting in the spring and the gestation period lasting around 7 months, ending with the birth of one to two young. It has been recorded in captive environments that the jewelled gecko mating time is some time between September and October, and the birth time is February to May. This species basks in the sun on top of foliage especially on warm sunny mornings and does this year round. It has been shown that pregnant females are the easiest to find, and this is most likely due to needing the sun more to help development of young.

Diet/Prey/Predators

Diet and foraging

The jewelled gecko, like other geckos, has a rich diet of insects and berries that come from its habitat of native forest and shrublands. All New Zealand geckos like the jewelled gecko are omnivores and eat a wide variety of insects such as moths and different types of flies, and they also feed on berries from native plants such as those of the genus ''

Coprosma ''Coprosma'' is a genus of flowering plants in the family Rubiaceae. It is found in New Zealand, Hawaiian Islands, Borneo, Java, New Guinea, islands of the Pacific Ocean to Australia and the Juan Fernández Islands. Description The name ''Copros ...

''. New Zealand geckos have also been known to feed on the nectar of flowers when available.

Predators, parasites and diseases

There are many threats that the jewelled gecko faces from farmland grazing,

, predators, and illegal poaching. The jewelled gecko is protected under the Wildlife Act of 1953, but its habitats are still being destroyed by either fragmentation by roads or invasive species. The predators that this gecko faces include humans, rodents, mustelids, cats, birds and possums. The human factor is all the illegal poaching that is going on in the predator proof areas and natural areas. Rodents, rats, are a large predator for the jewelled gecko, climbing the branches of the shrubland and forest and infiltrating its habitat. However, there is evidence to show that

mustelids The Mustelidae (; from Latin , weasel) are a diverse family of carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the suborder Can ...

and cats are not main predators because they are mainly

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

in their hunting behavior. Birds in New Zealand, particularly the magpie and kingfishers, are known to feed on the jewelled gecko. As for other pest mammals, such as possums or hedgehogs, these could possibly pose a problem if encountered, but they are not a main threat to the species. The only known and recorded parasite for the jewelled gecko is the ectoparasite '' Neotrombicula naultini''.

Cultural significance

There is a large cultural significance tied to the jewelled gecko and many more green species of geckos. The

Ngāi Tahu Ngāi Tahu, or Kāi Tahu, is the principal Māori people, Māori (tribe) of the South Island. Its (tribal area) is the largest in New Zealand, and extends from the White Bluffs / Te Parinui o Whiti (southeast of Blenheim, New Zealand, Blenhe ...

people of the South Island of New Zealand refer to these geckos as ''

taonga ''Taonga'' or ''taoka'' (in South Island Māori) is a Māori-language word that refers to a treasured possession in Māori culture. It lacks a direct translation into English, making its use in the Treaty of Waitangi significant. The current ...

'' (an object or natural resource which is highly prized), and they are highly thought of in their culture.