Rhabdophis tigrinus is known to engage in a defensive posture whereby it raises the back of its neck, displaying its nuchal glands (Mori and Burghardt, 2001). Studies have shown that R. tigrinus from a toad-free island (chemically undefended snakes) of Japan are less likely to engage in this defensive display, and more likely to flee (Mori and Burghardt, 2000).
In addition to the nuchal gland display, R. tigrinus is known to flatten its neck and and body, and death feign (Mutoh, 1983). This is a characteristic that has been observed in several bufophagous snakes (McDonald, 1974; Gregory et al., 2007).
Rhabdophis tigrinus is a diurnal, olive green snake. The snout-vent length of Rhabdophis tigrinus males ranges between 60-90 cm and 60-260 grams (Tanaka and Ota, 2002). Females range between 65-130 cm and 80-800 grams (Tanaka and Ota, 2002).
The diet of Rhabdophis tigrinus consists exclusively of anurans. It is one of few species in the world who are capable of consuming toads (are bufophagous) with no apparent ill effects (Hutchinson et al., 2007). These snakes have evolved a resistance to the toxic effects of bufadienolides, a class of cardiotonic steroids produced in the parotoid glands and skin of toads as chemical defense. The diet of R. tigrinus is not, however, exclusively restricted to toads, they will generally consume any anuran they come across (Tanaka and Ota, 2002; Hirai, 2004).
Rhabdophis tigrinus is a member of a unique group of Asian natricines who posses specialized nuchal glands of the back of their necks. Recent studies on this species has revealed that they sequester bufadienolides from the toads they consume into those nuchal glands (Hutchinson et al., 2007), a mechanism never previously documented in snakes. Further research has revealed that in addition to chemically defending themselves, females pass bufadienolides into the nuchal glands of their offspring through the yolk, thereby producing chemically defended hatchlings (Hutchinson et al., 2008).
Rhabdophis tigrinus, also known commonly as the tiger keelback,[2] kkotbaem, or yamakagashi, is a species of venomous snake in the subfamily Natricinae of the family Colubridae. The species is native to East Asia and Southeast Asia. Many sources, though not ITIS,[3] recognize one subspecies, Rhabdophis tigrinus formosanus of Taiwan.[2][4]
The dorsal color pattern of R. tigrinus is olive-drab green, with black and bright orange crossbars or spots from the neck down the first third of the body. The belly is whitish. The average total length (including tail) is usually 60–100 cm (24–39 in).[5]
R. tigrinus is found in eastern Russia (Primorskiy and Khabarovsk), North and South Korea, China (widespread, except in the western third and the extreme south; Zhejiang, Fujian, Jiangxi, Hubei, Guizhou, Sichuan, Gansu, Shaanxi and Inner Mongolia), on the island of Taiwan, in Vietnam and in Japan (Yakushima, Tanegashima, Kyūshū, Shikoku, Honshu, Osaka and in the Ryukyu Islands). The type locality given is "Japan".[2]
The diet of R. tigrinus consists mainly of small vertebrates, especially frogs and toads. It forages using both chemical (smell/tongue) and visual cues to find its prey.[6]
Rhabdophis tigrinus has two rows of glands in its neck that provide protection from predators by releasing steroidal toxins that are sequestered from ingested poisonous toads, referred to as kleptotoxisism.[7] When this species is challenged at cooler temperatures it tends to demonstrate passive anti-predator responses such as flattening the neck and body and lying still, while at higher temperatures it more frequently flees instead.[8] This snake thus appears to rely more heavily on the deterrence provided by these glands at low ambient temperatures.[8] Although venomous, few deaths have been recorded due to its tendency to display one of these other behaviors as opposed to striking. This hesitancy to strike at a predator in turn may be because its fangs are located in the back of the mouth, making a successful strike on a large object difficult.[9]
{{cite web}}: CS1 maint: multiple names: authors list (link) Rhabdophis tigrinus, also known commonly as the tiger keelback, kkotbaem, or yamakagashi, is a species of venomous snake in the subfamily Natricinae of the family Colubridae. The species is native to East Asia and Southeast Asia. Many sources, though not ITIS, recognize one subspecies, Rhabdophis tigrinus formosanus of Taiwan.
