''Boiga'' is a large

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of rear-fanged, mildly

venomous snake ''Venomous snakes'' are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow ...

s, known commonly as cat-eyed snakes or simply cat snakes, 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 ...

Colubridae Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...

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), ...

of the genus ''Boiga'' are native to southeast

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

, and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, but due to their extremely hardy nature and adaptability, have spread to many other suitable habitats around the world. There are 38 recognized

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), ...

in the genus. According to the study done by Jiří Smíd regarding Old World cat snakes, the ancestor of the cat snake originated in Africa, from where it diversified and expanded to other countries. Despite this diversity however, the different species have very similar needs in terms of temperature and precipitation.

Species and subspecies

The following species and subspecies are recognized as being valid. *'' Boiga andamanensis'' – Andaman cat snake *'' Boiga angulata'' – Leyte cat snake – Philippines *'' Boiga barnesii'' – Barnes' cat snake – Sri Lanka *'' Boiga beddomei'' – Beddome's cat snake – Western Ghat mountains and Sri Lanka *'' Boiga bengkuluensis'' – *'' Boiga bourreti'' – Bourret's cat snake – central Vietnam *'' Boiga ceylonensis'' – Sri Lanka cat snake *'' Boiga cyanea'' – green cat snake –

Mainland Southeast Asia Mainland Southeast Asia (historically known as Indochina and the Indochinese Peninsula) is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to th ...

to eastern India *'' Boiga cynodon'' – dog-toothed cat snake – Sundaland and Philippines *'' Boiga dendrophila'' – gold-ringed cat snake, mangrove snake **''Boiga dendrophila annectens'' **''Boiga dendrophila dendrophila'' **''Boiga dendrophila divergens'' **''Boiga dendrophila gemmicincta'' **''Boiga dendrophila latifasciata'' **''Boiga dendrophila levitoni'' **''Boiga dendrophila multicincta'' **''Boiga dendrophila occidentalis'' *'' Boiga dightoni'' – Pirmad cat snake – India (Western Ghats) ** '' Boiga dightoni whitakeri'' – Whitaker's cat snake *'' Boiga drapiezii'' – white-spotted cat snake *'' Boiga flaviviridis'' - yellow-green cat snake - eastern peninsular India *'' Boiga forsteni'' – Forsten's cat snake – Indian subcontinent *'' Boiga gocool'' – arrowback tree snake – Bengal, Assam *'' Boiga guangxiensis'' – southern China, Laos, Vietnam *'' Boiga hoeseli'' - Lesser Sundas cat snake *'' Boiga irregularis'' – brown tree snake *'' Boiga jaspidea'' – jasper cat snake - Sumatra, Java, Malay peninsula, Borneo *'' Boiga kraepelini'' – Kelung cat snake – China, Taiwan, Hainan, Vietnam *'' Boiga melanota'' *'' Boiga multifasciata'' – many-banded cat snake *'' Boiga multomaculata'' – many-spotted cat snake – Himalayan foothills (Himachal Pradesh to Sikkim, Nepal, Bhutan) *'' Boiga nigriceps'' – black-headed cat snake – Sumatra, Malay Peninsula, Borneo *'' Boiga nuchalis'' – collared cat snake – southwestern India (Western and Eastern Ghats) *'' Boiga ochracea'' – tawny cat snake *'' Boiga philippina'' – Philippine cat snake *'' Boiga quincunciata'' – Assam, Burma *'' Boiga ranawanei'' – Ranawana's cat snake – Sri Lanka *'' Boiga saengsomi'' – banded cat snake *'' Boiga schultzei'' – Schultze's blunt-headed tree snake *'' Boiga siamensis'' – gray cat snake *'' Boiga tanahjampeana'' *'' Boiga thackerayi'' – Thackeray's cat snake – Western Ghats *'' Boiga trigonata'' – Indian gamma snake **''Boiga trigonata trigonata'' **''Boiga trigonata melanocephala'' *'' Boiga wallachi'' – Nicobar cat snake *'' Boiga westermanni'' – Indian egg-eating snake ''

Nota bene ( ; plural: ) is the Latin language, Latin phrase meaning ''note well''. In manuscripts, ''nota bene'' is abbreviated in upper-case as NB and N.B., and in lower-case as n.b. and nb; the editorial usages of ''nota bene'' and ''notate bene'' fi ...

'': A

binomial authority In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...

in parentheses indicates that the species was original described in a genus other than ''Boiga''.

Phylogeny

DNA analysis indicates that ''Boiga'' is a sister group to '' Toxicodryas'' and '' Dasypeltis''. Three main clades were identified: (A) ''B. kraepelini''; (B) seven species, ''B. jaspidea, B. barnesii, B. beddomei, B. ceylonensis, B. quincunciata, B. trigonata, maculata–ochracea''; (C) remainder of approximately seventeen species. Within Clade C, subclades include: ''B. bouretti'', ''drapezii'' group, ''cynodon'' group, ''irregularis'' group, ''B. philippina'', ''B. nigriceps'', ''dendrophila'' group.

Description

Cat snakes are long-bodied snakes with large heads and large

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

s. They vary greatly in pattern and color. Many species have banding, but some are spotted and some are solid-colored. Colors are normally

black Black is a color that results from the absence or complete absorption of visible light. It is an achromatic color, without chroma, like white and grey. It is often used symbolically or figuratively to represent darkness.Eva Heller, ''P ...

brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors Orange (colour), orange and black. In the ...

, or

green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a com ...

with

white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In t ...

accents.

Behaviour

Snakes of the genus ''Boiga'' are primarily

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 ...

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 ...

snakes.

Diet

Snakes of the genus ''Boiga''

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

on various small species of

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 ...

s, snakes,

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s, and

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

Venom

The toxicity of ''Boiga'' venom varies from species to species, but is not generally considered to be life-threatening to humans. Since their venom does not usually harm humans, they are popular exotic pets.

Reproduction

''Boiga'' species are

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

In captivity

''Boiga dendrophila'' is by far the most common species in captivity, but ''B. cyanea'' and ''B. nigriceps'' are also found. Nowadays, ''B. cynodon'', ''B. philippina'' and a “Katherine morph” of ''B. irregularis'' are also circulating in the South-East Asian exotic pet trade. Others are not commonly available. They are hardy and adaptable and tend to do well in captivity after the initial period of stress from the importation process is passed. They are not bred commonly in captivity, so most specimens available are wild caught, and thus are prone to heavy internal

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

load. Adjusting them to a

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

only diet can be difficult for the inexperienced

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

keeper.

Invasive species

''Boiga irregularis'' in particular has been federally banned in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

because of its effect by accidentally being introduced to the island of

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

. Some time during the 1950s, some ''B. irregularis'' of both sexes (or possibly a single female with

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

s) reached the island, possibly having hidden in imported

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

pots. The island of Guam lacks native snakes or predators that can deal with snakes the size and aggressiveness of ''B. irregularis''. As a result, it has bred unchecked as an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

, and has begun consuming the island's bird life in extreme numbers. Dozens of bird species have been completely eradicated from the island, many species that were found nowhere else on earth, and the snake has reached astonishing population densities, reported to be as high as 15,000 snakes per square mile. In addition to devouring the native

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

, this species will routinely crawl into power transformers, and this typically results in both an electrocuted snake and substantial blackouts. In addition, there has been many cases in Guam where deaths are recorded due to the venomous bites from the Boiga snakes. Although they are an invasive species, there has been evidence where there is reverse- colonization of South-East Asia from the Philippines, and the Australasia from Wallacea from multiple lineages within Boiga.

References

External links

Wild Herps.com: Eastern Brown Tree SnakeGernot-Vogel.de: Checklist of the Genus ''Boiga'' (Serpentes: Colubridae)
{{Authority control Boiga Snakes of Australia Reptiles of India Reptiles of Asia Reptiles of Pakistan Snake genera Taxa named by Leopold Fitzinger