Breed reptiles in captivity: Snakes – Vipers
Overall effectiveness category Awaiting assessment
Number of studies: 13
Background information and definitions
Captive breeding involves taking wild animals into captivity and establishing and maintaining breeding populations. It tends to be undertaken when wild populations become very small or fragmented or when they are declining rapidly. Captive populations can be maintained while threats in the wild are reduced or removed and can provide an insurance policy against catastrophe in the wild. Captive breeding also potentially provides a method of increasing reproductive output beyond what would be possible in the wild. However, captive breeding can result in problems associated with inbreeding depression, removal of natural selection and adaptation to captive conditions. The aim is usually to release captive-bred animals back to natural habitats, either to original sites once conditions are suitable, to reintroduce species to sites that were occupied in the past or to introduce species to new sites. Some captive populations may also be used for research to benefit wild populations.
Due to the number of studies found, this action has been split by species group, though no studies were found for amphisbaenians. See here for other species groups.
For studies that investigate the effectiveness of releasing captive-bred reptiles see Release captive-bred reptiles into the wild.
Supporting evidence from individual studies
A study in 1972–1976 at Fort Worth Zoological Park, and a second private collection, USA (Tryon & Radcliffe 1977) reported that lower California rattlesnakes Crotalus enyo enyo bred successfully in captivity. In 1974–1976, three females produced four litters of 2–7 young each following gestation periods of 176–299 days. One litter of seven included two young that were stillborn and one that died soon after birth. The overall sex ratio was 12 males to two females and one of unknown sex. In 1972–1974, one female and one male snake were acquired by Fort Worth Zoo, and two females and a male were acquired by a second private collection. Snakes were housed in a 60 cm fibreglass exhibit with a gravel substrate, or a 38 litre tank with a newspaper substrate. Temperatures ranged from 22–33°C.Study and other actions tested
A study in 1969–1978 at Columbus Zoo, Ohio, USA (Goode 1979) reported that two generations of Palestine saw-scaled vipers Echis coloratus bred successfully in captivity. After not reproducing for two years, a female produced seven clutches of 5–12 eggs over seven years. Three females from the first of these clutches (hatched in 1971) went on to produce a total of four clutches of 1–9 eggs over three years. In total, 49 of 72 eggs hatched successfully, with an average hatching success/clutch of 64%, though three hatchlings died within 24 hours of emergence. Six clutches also contained 1–3 infertile egg masses. In 1964–1968, a pair of snakes was acquired and in 1969 they were placed together. The original pair were housed in a display cage (68 x 56 x 52 cm), and offspring were housed individually and then combined into groups during the spring in aquaria of various sizes.Study and other actions tested
A study in 1973–1978 in Texas, USA (Hubbard 1980) reported that a pair of lancehead rattlesnakes Crotalus polystictus bred successfully after five years in captivity. In 1978, the female gave birth to a litter of three young. The pair of snakes was brought into captivity in 1973 and housed in a glass fronted display (60 x 40 x 55 cm) with a substrate of small rocks. Cover was provided by larger rocks, leaves and dried plants. Temperatures were maintained at 29°C.Study and other actions tested
A replicated study in 1972–1978 [location unknown] (Naulleau & van den Brule 1980) found that Russell's vipers Vipera russelli bred successfully in captivity. In 1972–1978, eight females each produced one litter of 9–22 live young. The average sex ratio of litters was eight females for every six males. Five pregnant vipers were imported from Pakistan (origin unclear) and the other three females were captive born. Snakes were kept in large terraria (3.8 x 2.3 x 1.1 m) and smaller cages (0.5–1.0 x 0.5 x 0.5 m), with a thermal gradient of 18–50°C and minimum temperature of 18°C at night.Study and other actions tested
A study in 1973–1979 at the Oklahoma City Zoo, USA (West 1981) found that Mexican cantils Agkistrodon bilineatus bred successfully in captivity. In 1973, two females produced one litter each of six and 12 live young, though six young died shortly after birth. In 1977, one female produced a litter of nine young, two of which were still alive after three months, and one of which survived at least 2 years. In 1966–1973, a male and two females were acquired. They were housed together from 1973 in a glass-fronted wooden enclosure (79 x 61 x 46 cm) with a gravel substrate, rocks and plastic vegetation. The male died following removal of a tumour in December 1976.Study and other actions tested
A study in 1970–1980 at the Houston Zoological Gardens, USA (Carl et al. 1982) found that Uracoan rattlesnakes Crotalus vegrandis bred successfully in captivity. In 1976–1980, two females produced five litters of 2–8 young. In 1970, a gravid female was brought into captivity and produced a litter of three young. In 1970, two females and a male were brought into captivity. They were housed in either an exhibit (80 x 90 x 140 cm) with a substrate of gravel, rocks and plastic plants, or aquaria of various sizes with a paper substrate and hide boxes. Temperature was maintained at 28°C and humidity at 75%. Adult snakes were occasionally temporarily separated and then returned to the same enclosure.Study and other actions tested
A study in 1969–1980 at Houston Zoological Gardens, USA (Carl et al. 1982) found that Aruba Island rattlesnakes Crotalus unicolor bred successfully in captivity. In 1973–1980, four females produced a total of nine litters of 2–5 live young/litter, or 3–8/litter when including still born young and infertile eggs. Three of these litters (2–4 live young/litter) were produced by two females born in captivity. The oldest female also produced a single infertile egg on three occasions. In 1969–1976, two female and two male snakes were acquired. Snakes were housed in a glass fronted enclosure (80 x 90 x 140 cm) with a gravel substrate, rocks and plastic plants, or in aquaria of various sizes with a paper substrate and hide boxes. Temperatures were maintained at 28°C and humidity was 85% in the enclosure and 75% in the aquaria. Snakes were occasionally temporarily separated and then returned to the same enclosure.Study and other actions tested
A study in 1981–1982 at Fort Worth Zoological Park, USA (Blody 1983) found that eyelash vipers Bothrops schlegeli bred successfully in captivity. In 1981–1982, three females produced a total of five litters of 6–17 young/litter. In 1981, four captive born snakes (3 females, 1 male) and one of unknown origin (male) were acquired and housed in either a 91 cm fibreglass enclosure with a gravel substrate or in glass aquaria with a newspaper substrate. Rocks, plastic plants, branches and a water bowl were provided. Temperatures were maintained at 24.4–29.4°C. Offspring were removed and placed in plastic containers of various sizes.Study and other actions tested
A study in 1978–1982 at Dallas Zoo, USA (Perry & Blody 1986) found that Cretan vipers Vipera lebetina schweizeri bred successfully in captivity. In 1980–1982, two years after a male and female were first housed together, the female produced 26 eggs, 21 of which hatched successfully. The incubation period ranged from 37–48 days. An adult pair of Cretan vipers were housed in a fibreglass enclosure (78 x 60 x 30 cm) with a sand and gravel substrate that was maintained at a temperature of 26–29°C. A container filled with moist sphagnum Sphagnum sp. was provided for egg laying, and eggs were collected and incubated at 27–31°C.Study and other actions tested
A study in 1985–1986 in the USA (Hitchiner 1987) found that eyelash vipers Bothrops schlegeli bred successfully in captivity. In 1986, two females gave birth to 15 and 18 live young each following gestation periods of at least 237 and 338 days. In 1985, two females were placed with a male in a glass aquarium (60 x 40 x 32 cm). The male was removed one month later. Temperatures varied from 19–35°C under a heat lamp each day.Study and other actions tested
A study in 1989–1991 [location unknown] (Kudrjavtsev & Mamet 1991) found that two captive female Radde’s vipers Vipera raddei raddei bred successfully in captivity. In 1991, one female gave birth to one live young and three infertile egg masses, and the other female gave birth to three young and two infertile egg masses. The young snakes survived for at least eight months. Adult snakes were placed together in a 140 x 60 x 60 cm terrarium, with a substrate of fine gravel, larger rocks, and shelters made from bark and plywood. The terrarium was kept at a temperature of around 25–32oC.Study and other actions tested
A study in 1999–2003 [location unknown] (Jandzik 2007) found that Nikolsky's adders Vipera nikolskii reproduced successfully in captivity in one of two years. In 2002, one female produced five infertile egg masses. In 2003, one female produced seven live young, and a second female produced three live young and four infertile egg masses. Two of the young snakes had physical deformities and a third died shortly after emergence. One pair of adult snakes died soon after arriving in captivity. In 1999–2000, three pairs of snakes were acquired from Ukraine. Snakes were housed with a newspaper substrate and plastic hide box, and temperatures were maintained at 22–28°C during the day with a basking area at 35°C, and 18–22°C at night. Juvenile snakes were moved in groups of 2–3 to small containers with a paper substrate, where temperatures were maintained at 22–25°C during the day and 20–22°C at night.Study and other actions tested
A study in 2007–2013 in Medellín, Colombia (Duque & Corrales 2015) found that one pair of Chocoan bushmasters Lachesis acrochorda bred successfully in captivity. A female produced a clutch of 11 eggs, seven of which hatched successfully. Incubation periods ranged from 93–96 days. None of three eggs that were removed and incubated artificially fully developed. In 2007–2013, two female and two male snakes were held together in an enclosure (3.6 x 2.5 x 2.7 m) with a substrate of gravel, soil and rice husks, with a water source, larger rocks and plants. Temperatures were maintained at 19–28°C and humidity at 75–95%. In February 2013, just prior to the breeding event, humidity was increased to >85%. Three eggs were removed and incubated in a 1:1 mix of vermiculite and water at 24.6–25°C and 77–80% humidity. The remaining eight eggs were left in the enclosure for 74 days, at which point they were moved to an incubator, with temperatures of 24.5–27.7°C and 78–91% humidity.Study and other actions tested