# Oligodon

Oligodon is genus of colubrid snakes that was first described by Austrian zoologist Leopold Fitzinger in 1826. This genus is widespread throughout central and tropical Asia. The snakes of this genus are commonly known as kukri snakes.

## Description

The species in the genus Oligodon are egg eaters and are usually under 90 cm (35 in) in total length (including tail). Different species display widely variable patterns and colorations. They subsist mostly by scavenging the eggs of birds and reptiles. Besides eggs, species of this genus also feeds on lizards, frogs, and small rodents.
Oligodon is a rear-fanged snake genus. All member species have a set of enlarged teeth placed in the back of the upper jaws, as well as functional Duvernoy's glands. They are not dangerous to humans, though. Bites by some species have been reported to bleed excessively, suggesting presence of anticoagulants in the Duvernoy's gland secretions. Species of Oligodon are mostly nocturnal, and live on the floor of mature forests.
The common name of the genus comes from the kukri, a distinctively shaped Nepalese knife, which is similar in shape to the broad, flattened, curved hind teeth of Oligodon species. These teeth are specially adapted for their main diet of eggs; the teeth cut open eggs as they are being swallowed by the snake, allowing for easier digestion.
At least three species (O. fasciolatus, O. formosanus and O. ocellatus) will slice open the abdomens of frogs and toads and devour their internal organs, before finally swallowing the prey whole (if the prey is not too large to be swallowed). That toads can be swallowed whole suggests that at least some species are immune to toad bufotoxin.
* O. fasciolatus eating Asian common toad
* O. ocellatus eating an Asian common toad.
* O. formosanus eating a banded bullfrog

## Species

There are 84 recognized species in the genus Oligodon according to Reptile Database as of April 2023.
The source column gives direct links to the sources used:
* IUCN description of species at International Union for Conservation of Nature Red List of Threatened Species. IUCN Red List categories are:
       EX - Extinct, EW - Extinct in the Wild
       CR - Critically Endangered, EN - Endangered, VU - Vulnerable
       NT - Near Threatened, LC - Least Concern
       DD - Data Deficient, NE - Not Evaluated
* RDB description of species at Reptile Database.
Nota bene: A binomial authority in parentheses indicates that the species was originally described in a genus other than Oligodon.
| Common name | Species | Geographic range | Status | Source |
| Western kukri snake, Malabar brown kukri snake | O. affinis Günther, 1862 | India (Kerala, Tamil Nadu) | LC | IUCN RDB |
| Light-barred kukri snake | O. albocinctus (Cantor, 1839) | Nepal, Bangladesh, India (Assam, Sikkim, Arunachal Pradesh), Myanmar, Vietnam, China (Tibet, Yunnan) | | RDB |
| Northern short-headed snake | O. ancorus (Girard, 1858) | Philippines (Mindoro, Luzon) | NT | IUCN RDB |
| Annam kukri snake | O. annamensis Leviton, 1953 | Vietnam (Lam Dang Province) | DD | IUCN RDB |
| Spotted kukri snake, ringed kukri snake | O. annulifer (Boulenger, 1893) | Brunei, Malaysia (Sabah, Sarawak) | LC | IUCN RDB |
| Russet kukri snake, common kukri snake, banded kukri | O. arnensis (Shaw, 1802) | Bangladesh, Sri Lanka, India (West Bengal, Kerala, Tamil Nadu, Karnataka, Andhra Pradesh, Gujarat, Madhya Pradesh, Uttar Pradesh, Himachal Pradesh, Maharashtra, Punjab), Pakistan, Nepal | | RDB |
| Barron's kukri snake | O. barroni (M.A. Smith, 1916) | Thailand, Southern Vietnam, Cambodia, South Laos | LC | IUCN RDB |
| Javanese mountain kukri snake, Boie's kukri snake | O. bitorquatus F. Boie, 1827 | Indonesia (Java, possibly South Sumatra and Sumbawa) | LC | IUCN RDB |
| Double-striped kukri snake | O. bivirgatus T. Qian, S. Qi, J. Shi, Y. Lu, R.W. Jenkins, Y. Mo & P. Li, 2021 | China (Hainan) | | RDB |
| Boo-Liat's kukri snake | O. booliati Leong & Grismer, 2004 | Malaysia (Tioman island) | CR | IUCN RDB |
| Short-tailed kukri snake, shorthead kukri snake | O. brevicauda Günther, 1862 | India (Tamil Nadu, Kerala) | VU | IUCN RDB |
| Templeton's kukri snake | O. calamarius (Linnaeus, 1758) | Sri Lanka | EN | RDB |
| Assam kukri snake | O. catenatus (Blyth, 1854) | India, Myanmar, Thailand, Vietnam, Cambodia, South China (Guangdong, Guangxi) | | RDB |
| Chinese kukri snake | O. chinensis (Günther, 1888) | southern China, northern Vietnam | LC | IUCN RDB |
| Churah Valley kukri snake | O. churahensis Mirza, Bhardwaj & Patel, 2021 | India (Himachal Pradesh) | | |
| Black cross-barred kukri snake, ashy kukri snake, golden kukri snake, Günther's kukri snake | O. cinereus (Günther, 1864) | India (Assam, Arunachal Pradesh), Bangladesh, Cambodia, Laos, Vietnam, Myanmar, Thailand, peninsular Malaysia, China (Yunnan, Hong Kong, Hainan, Guangxi, Fujian, Guangdong) | LC | IUCN RDB |
| | O. condaoensis S.N. Nguyen, V.D.H. Nguyen, S.H. Le & R. Murphy, 2016 | S Vietnam (Hon Ba Island) | | RDB |
| Pegu kukri snake | O. cruentatus (Günther, 1868) | Myanmar | LC | IUCN RDB |
| | O. culaochamensis S.N. Nguyen et al., 2017 | Vietnam | | RDB |
| North-east Indian kukri snake, Cantor's kukri snake | O. cyclurus (Cantor, 1839) | India (Assam), Myanmar, Thailand, Laos, Cambodia, Vietnam, China (Yunnan), Nepal, Bangladesh | LC | IUCN RDB |
| | O. deuvei David, G. Vogel & van Rooijen, 2008 | Cambodia, southern Vietnam, Laos, North East Thailand | LC | IUCN RDB |
| Gray's kukri snake, Bengalese kukri snake | O. dorsalis (Gray & Hardwicke, 1835) | India (Assam), Bhutan, Bangladesh, Myanmar, Thailand | | RDB |
| Eberhardt's kukri snake | O. eberhardti Pellegrin, 1910 | Vietnam, China (Guangxi, Fujian), possibly Laos, Cambodia and Myanmar | LC | IUCN RDB |
| Nagarkot kukri snake | O. erythrogaster Boulenger, 1907 | Central and East Nepal, India (Sikkim) | | RDB |
| Red-striped kukri snake, Namsang kukri snake | O. erythrorhachis Wall, 1910 | India (Arunachal Pradesh) | VU | IUCN RDB |
| Jewelled kukri snake, Everett's kukri snake | O. everetti Boulenger, 1893 | Indonesia (Kalimantan), Malaysia (Sabah) | LC | IUCN RDB |
| Small-banded kukri snake, fasciolated kukri snake | O. fasciolatus (Günther, 1864) | Myanmar, Thailand, Laos, Cambodia, Vietnam | LC | IUCN RDB |
| Forbes' kukri snake | O. forbesi (Boulenger, 1883) | Indonesia (Selaru and Yamdena in Tanimbar Islands) | NT | IUCN RDB |
| Taiwan kukri snake, Formosa kukri snake | O. formosanus (Günther, 1872) | Vietnam, Taiwan, South Japan (Ryukyu Islands, primarily Okinawa, Miyako and Yaeyama Islands), South China (Chekiang, Jiangxi, Fujian, Guangdong, Nan Ao Island, Hainan, Guangxi, Hong Kong, Zhejiang, Yunnan) | | RDB |
| Hampton's kukri snake | O. hamptoni Boulenger, 1918 | Myanmar | DD | IUCN RDB |
| Hua Hin Kukri Snake | O. huahin Pauwels, Larsen, Suthanthangjai, David & Sumontha, 2017 | Thailand (Hua Hin) | DD | |
| Inornate kukri snake, unicolored kukri snake | O. inornatus (Boulenger, 1914) | Cambodia, North and East Thailand | LC | IUCN RDB |
| Jintakune's kukri snake | O. jintakunei Pauwels, Wallach, David, Chanhome, 2002 | South Thailand | DD | IUCN RDB |
| Grey kukri snake, Joynson's kukri snake | O. joynsoni (M.A. Smith, 1917) | northern Thailand, possibly Laos, Myanmar, China (Yunnan) | LC | IUCN RDB |
| Walnut kukri snake | O. juglandifer (Wall, 1909) | India (Sikkim), West Bhutan | VU | IUCN RDB |
| | O. kampucheaensis Neang, Grismer & Daltry, 2012 | Cambodia | | RDB |
| coral red kukri snake | O. kheriensis Acharji & Ray, 1936 | India (Uttar Pradesh), Southwest Nepal | | RDB |
| Lacroix kukri snake | O. lacroixi Angel & Bourret, 1933 | China (Sichuan, Yunnan), Vietnam | VU | IUCN RDB |
| Medog kukri snake | O. lipipengi Jiang, Wang, Li, Ding, Ding & Che, 2020 | China (Tibet) | | RDB |
| | O. lungshenensis Zheng & Huang, 1978 | China (Chongqing, Guangxi, Guizhou, Hunan) | NT | IUCN RDB |
| Angel's kukri snake | O. macrurus (Angel, 1927) | Vietnam | DD | IUCN RDB |
| Barred short-headed snake, spotted kukri snake | O. maculatus (Taylor, 1918) | Philippines (Mindanao) | LC | IUCN RDB |
| Arakan kukri snake, McDougall's kukri snake | O. mcdougalli Wall, 1905 | Myanmar | LC | IUCN RDB |
| Bluebelly kukri snake | O. melaneus Wall, 1909 | India | | RDB |
| Abor Hills kukri snake | O. melanozonatus Wall, 1922 | India, China (Tibet) | | RDB |
| Sulu short-headed snake, Meyerink's kukri snake | O. meyerinkii (Steindachner, 1891) | Philippine Islands (Bongao, Jolo, Papahang, Sibutu, Tawi-Tawi in Sulu Archipelago), possibly Malaysia (Sabah) | EN | IUCN RDB |
| Spotted-bellied short-headed snake, Luzon kukri snake | O. modestus Günther, 1864 | Philippines (Mindanao, Negros, Tablas, Panay, Cebu, possibly Luzon) | VU | IUCN RDB |
| Morice's kukri snake | O. moricei David, G. Vogel & van Rooijen, 2008 | Southern Vietnam | DD | IUCN RDB |
| Cambodian kukri snake, Mouhot's kukri snake | O. mouhoti (Boulenger, 1914) | Cambodia, East Thailand | LC | IUCN RDB |
| Nagao kukri snake | O. nagao David, T.Q. Nguyen, T. Nguyen, Jiang, T. Chen, Teynié & Ziegler, 2012 | Northern Vietnam, Southwest China (Guangxi), Laos | | RDB |
| Nikhil's kukri snake | O. nikhili Whitaker & Dattatri, 1982 | India (Tamil Nadu) | DD | IUCN RDB |
| Palawan kukri snake, Palawan short-headed snake | O. notospilus Günther, 1873 | Philippine Islands (Palawan, Busuanga, Balabac, Mindanao) | | RDB |
| Eyed kukri snake, ocellated kukri snake | O. ocellatus (Morice, 1875) | Cambodia, Lao, southern Vietnam | LC | IUCN RDB |
| Eight-lined kukri snake, eight-striped kukri snake, Grace's kukri snake | O. octolineatus (Schneider, 1801) | Brunei, Indonesia (Java, Borneo, Sumatra), Malaysia (Peninsular Malaysia, Sabah, Sarawak), Singapore | LC | IUCN RDB |
| Ornate kukri snake | O. ornatus Van Denburgh, 1909 | China (Anhui, Fujian, Guangdong, Guangxi, Hunan, Jiangxi, Sichuan, Zhejiang), Taiwan, | LC | IUCN RDB |
| Perkin's short-headed snake | O. perkinsi (Taylor, 1925) | Philippines (Palawan, Culion and Calauit Islands) | NT | IUCN RDB |
| Petronella's kukri snake | O. petronellae Roux, 1917 | Indonesia (Sumatra) | DD | IUCN RDB |
| Pha-Ngan kukri snake | O. phangan Pauwels, Thongyai, Chantong & Sumontha, 2021 | Thailand (Surat Thani Province: Pha-Ngan Island) | | RDB |
| | O. planiceps (Boulenger, 1888) | Myanmar | LC | IUCN RDB |
| Pulau Weh kukri snake | O. praefrontalis F. Werner, 1913 | Indonesia (Weh Island) | DD | IUCN RDB |
| | O. promsombuti Pauwels, Thongyai, Chantong, & Sumontha, 2021 | Thailand (Surat Thani Province, Trang Province: Na Yong District) | | RDB |
| Bleeker's Kukri Snake | O. propinquus Jan, 1862 | Indonesia (Java) | | RDB |
| False striped kukri snake | O. pseudotaeniatus David, G. Vogel & van Rooijen, 2008 | Thailand | LC | IUCN RDB |
| | O. pulcherrimus F. Werner, 1909 | Indonesia (Sumatra) | VU | IUCN RDB |
| Purple kukri snake, brown kukri snake | O. purpurascens (Schlegel, 1837) | Brunei, Indonesia (Bali, Java, Kalimantan, Sumatra), Malaysia (Peninsular Malaysia, Sabah, Sarawak), Singapore, Thailand | LC | IUCN RDB |
| Long-snouted kukri snake | O. rostralis H.N. Nguyen, Tran, L.H. Nguyen, Neang, Yushchenko & Poyarkov, 2020 | Vietnam | | |
| Russell's kukri snake | O. russelius (Daudin, 1803) | India, Nepal | | |
| Saint Girons' kukri snake | O. saintgironsi David, G. Vogel & Pauwels, 2008 | Vietnam, Cambodia | DD | IUCN RDB |
| Sai Yok Kukri Snake | O. saiyok Sumontha, Kunya, Dangsri & Pauwels, 2017 | Thailand (Kanchanaburi) | DD |
| Half-keeled kukri snake, barred kukri snake, banded kukri snake | O. signatus (Günther, 1864) | Indonesia (Sumatra), Malaysia (Peninsular Malaysia, Sabah, Sarawak), Singapore | LC | IUCN RDB |
| Splendid kukri snake | O. splendidus (Günther, 1875) | Myanmar | LC | IUCN RDB |
| Duméril's kukri snake | O. sublineatus A.M.C. Duméril, Bibron & A.H.A. Duméril, 1854 | Sri Lanka | VU | IUCN RDB |
| Striped kukri snake | O. taeniatus (Günther, 1861) | Cambodia, Laos, Thailand, Vietnam, Myanmar, possibly China (Yunnan) | LC | IUCN RDB |
| Streaked Kukri snake, Loos snake | O. taeniolatus (Jerdon, 1853) | Afghanistan, India, Iran, Nepal, Bangladesh, Pakistan, Sri Lanka, Turkmenistan | LC | IUCN RDB |
| Teynié's kukri snake | O. teyniei David, Hauser & G. Vogel, 2022 | Laos | | |
| Mandalay kukri snake, Theobald's kukri snake | O. theobaldi (Günther, 1868) | Bangladesh, Myanmar | LC | IUCN RDB |
| Tillack's kukri snake | O. tillacki Bandara, Ganesh, Kanishka, Danushka, Sharma, P. Campbell, Ineich, G. Vogel & Amarasinghe, 2022 | India | | |
| | O. tolaki Amarasinghe, Henkanaththegedara, Campbell, Riyanto, Hallermann & G. Vogel, 2021 | Indonesia (Southeast Sulawesi) | | RDB |
| | O. torquatus (Boulenger, 1888) | Myanmar | DD | IUCN RDB |
| Travancore kukri snake | O. travancoricus Beddome, 1877 | India (Kerala, Tamil Nadu) | DD | IUCN RDB |
| Three-lined kukri snake | O. trilineatus (A.M.C. Duméril, Bibron & A.H.A. Duméril, 1854) | Indonesia (Nias, Siberut, Sumatra) | LC | IUCN RDB |
| Langbian kukri snake | O. tuani S.N. Nguyen, Le, Vo & R. Murphy, 2022 | Vietnam | | RDB |
| | O. unicolor (Kopstein, 1926) | Indonesia (Selaru, Yamdena) | NT | IUCN RDB |
| Jerdon's kukri snake | O. venustus (Jerdon, 1853) | India (Karnataka, Kerala, Tamil Nadu) | LC | IUCN RDB |
| Dark-spined kukri snake, vertebral kukri snake | O. vertebralis (Günther, 1865) | Indonesia (Kalimantan), Malaysia (Sabah) | DD | IUCN RDB |
| Bleeker's kukri snake | O. waandersi (Bleeker, 1860) | Indonesia (Java, Sulawesi, Buton, Sula Islands) | | RDB |
| Wagner's kukri snake | O. wagneri David & G. Vogel, 2012 | Indonesia (Nias) | | RDB |
| yellow-striped kukri snake | O. woodmasoni (Sclater, 1891) | India (Nicobar Islands, possibly Andaman Islands) | | RDB |