Action

Breed reptiles in captivity: Tortoises, terrapins, side-necked & softshell turtles

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (28 STUDIES)

  • Abundance (5 studies): Four studies (including one replicated study) in Madagascar, the Seychelles and the USA reported that captive breeding programmes produced 255 ploughshare tortoises, 40 and 140 giant tortoises, 75 juvenile radiated tortoises and 94 Madagascar big-headed turtle hatchlings. One study also reported that the captive population grew each year. One replicated study in Myanmar reported that the number of Burmese star tortoise hatchlings produced in captivity increased from 168 to over 2,000 over eight years.
  • Reproductive success (24 studies): Eighteen studies (including one replicated, controlled, before-and-after study) in the USA, the Galápagos, Germany, Austria, the Seychelles, Italy, India, China and an unknown location reported that females produced 0–25 clutches of 1–26 eggs, 65–78 eggs each/year or a total of 10–170 eggs. Three of these studies reported hatching success of 52–100%, four reported hatching success of 23–71%, three reported hatching success of 0–66%, 0–81% or 0–100% and six reported hatching success of 0–43% or 0–3 hatchings/clutch. One other study from the Seychelles reported that 0–75% of eggs from one of two mud turtle species hatched successfully. One of the studies also found that three of five eggs produced by a captive-bred tortoise hatched successfully. Two studies in Jersey and the Seychelles reported that only 3 Malagasy Flat-tailed tortoise eggs and 3–18 mud turtle eggs hatched successfully over 11–12 years. One study in Madagascar reported that most Madagascar big-headed turtle eggs laid in captivity were infertile. One study in the USA reported that hatching success of 2nd generation captive desert tortoises was 20–83%, whereas success for 3rd generation tortoises was 0–43%. One study in the USA found that hatching success for captive Bourret’s box turtle eggs was higher when incubated at 26–27°C compared to 28–29°C.
  • Survival (7 studies): Three studies (including one replicated study) in the USA, Austria and an unknown location reported that 2–4 captive-bred tortoises or turtles survived for at least 28 weeks to two years. One replicated study in Italy reported that all captive-bred spider tortoises survived to adult size. Two studies in the USA and Jersey reported that 25–30% of captive-bred tortoises died within 12–18 months. One study in the Seychelles reported that 70% of captive-bred mud turtles died during hatching

BEHAVIOUR (0 STUDIES)

OTHER (1 STUDY)

  • Offspring sex ratio (1 study): One study in the USA reported that a captive breeding programme of radiated tortoises produced 67 females and eight males.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A replicated study in 1965–1971 in a captive breeding facility in the Galápagos, Ecuador (MacFarland et al. 1974) found that Galápagos giant tortoise Geochelone elephantopus hoodensis bred in captivity. Over five nesting seasons, captive Galápagos giant tortoise females laid 19 nests in artificial nesting sites, two in natural nesting sites, and six clutches were laid on the surface of their enclosure (tortoises were unable to construct nests). For eggs that were collected and artificially incubated, 75% (24 of 32) were fertile and 63% (20 of 32) hatched successfully. In comparison, 80–86% (519 of 653 total eggs) of eggs from wild, undisturbed nests (of two other giant tortoise subspecies) were fertile, and hatching success was 76–82% (494 of 653 eggs) (results were not statistically tested). One male and ten female Galápagos giant tortoises were brought into a captive breeding enclosure to mate and nest from the 1967/1968 nesting season. In 1969/1970, 1970/1971 and 1971/1972 nesting seasons, artificial nest sites were provided (fine soil, minimum 3 m2 and 35–40 cm deep). Nests were excavated the day after being laid and moved for artificial incubation. Hatching success was evaluated for six clutches in the 1970/1971 nesting season (1–7 eggs/clutch) and compared to 81 clutches of Geochelone elephantopus porteri (520 total eggs) and Geochelone elephantopus ephippium (133 total eggs) laid in 1969/1970–1970/1971.

    Study and other actions tested
  2. A study in 1975 at Philadelphia Zoo, USA (Bowler 1975) reported that Galápagos giant tortoises Geochelone elephantopus produced one hatchling in captivity. A clutch of nine eggs was produced, one of which hatched successfully after an incubation period of 200 days. The hatchling had to be removed from the egg by hand. Four eggs were broken in the nest, and five were placed in the incubator, of which three were fertile. One was opened after 143 days and found to contain a live embryo, and one was opened after 211 days and contained a dead embryo. The adult male had been in captivity since 1928, and the adult female was hatched in captivity in 1940. Eggs were incubated at 26.7°C.

    Study and other actions tested
  3. A study in 1978–1982 in the USA (Coakley & Klemens 1983) reported that captive-born leopard tortoises Stigmochelys pardalis babcocki bred successfully in captivity and produced hatchlings in three of four years. From 1979–1982, a captive-born female produced 11 clutches of 1–9 eggs/clutch. The first five clutches produced no hatchlings, with most eggs breaking during laying. Subsequent clutches produced 1–3 hatchlings and incubation periods ranged from 135–202 days. In 1978–1981, a sibling pair of captive-hatched tortoises were housed together, and in 1981 an unrelated captive-hatched male was added to the pair. Tortoises were kept in an outdoor pen (5 x 3 m) when temperatures remained above 21°C during the day and 10°C at night and were otherwise housed in an indoor pen with a substrate of wood shavings. A heat-lamp was provided in the indoor pen and temperatures ranged from 21–40°C. In, 1979–1982, eggs were placed in a dry air incubator at 30°C.

    Study and other actions tested
  4. A replicated study in 1976–1981 in an outdoor enclosure in Germany (Kirsche 1984) reported that captive Hermann's tortoises Testudo hermanni hermanni, Greek tortoises Testudo graeca ibera and Russian tortoises Agrionemys horsfieldii bred successfully in captivity. In 1976–1981, ten females produced 65–78 eggs each year, with a hatching success of 23–71%. In 1981, a Hermann's tortoise that was hatched in captivity produced offspring (3 of 5 eggs hatched). Thirty tortoises were kept in an outdoor enclosure (180 m2) for 7–24 years and fed a mixture of vegetables. Twenty individuals were sexually mature, including seven male and eight female Hermann's tortoises; one male and one female Greek tortoise; and two male and one female Russian tortoise.

    Study and other actions tested
  5. A study in 1935–1986 in California, USA (Arneberg Booth & Buskirk 1988) found that 1st and 2nd generation captive desert tortoises Gopherus agassizii bred successfully in most years, but 3rd generation tortoises were successful in only two of 10 years. Authors reported only a subset of data. They estimated that the total number of eggs produced was 280 over 30 years by the 1st captive generation; 120 over 16 years by the 2nd generation; and 32 over 10 years by the 3rd generation. Reported hatching success was 20–83% for eggs produced by the 2nd generation, and 0–43% for those produced by the 3rd generation. All tortoises were descendants of an adult pair acquired in 1935 and were housed in outdoor enclosures. Eggs were collected from outdoor nests and placed in plastic bowls in 1 cm of washed sand. Bowls were covered with a damp cloth and temperatures were maintained at 26–27°C. When hatching began, eggs were moved to a sheet of waxed paper.

    Study and other actions tested
  6. A study in 1977–1986 at Columbus Zoo, Ohio, USA (Goode 1988) found that gibba turtles Mesoclemmys gibba reproduced successfully in captivity. In 1978–1982, one female produced seven clutches of 3–6 eggs. In 1985–1986, a further three females produced seven clutches of 2–7 eggs. Two of these females were offspring of the first pair. Incubation periods ranged from 140–248 days. The original male was acquired in 1968, and a female was acquired in 1977. Adults were housed along with a range of other turtle species in a 140 cm square display tank, with 50 cm deep water and a basking spot. Water temperature was 20–24°C and air temperatures were 24–32°C. Eggs were incubated at 26–31°C in sealed one-gallon jars in a 1:1 mixture of vermiculite and water (by weight), and jars were vented ever 4–6 weeks.

    Study and other actions tested
  7. A study in 1965–1990 at The National Zoological Park and a private collection, Washington DC, USA (Darlington & Davis 1990) found that pancake tortoises Malacochersus tornieri bred in captivity, but most eggs produced in one population were infertile. Hatching success was four of 65 eggs (6%) in the first population and three of seven (43%) in the second. Of the remaining eggs, 46 of 65 (71%) and two of seven (29%) were infertile. Four individuals survived for at least a year or less, and one survived at least nine years. The National Zoological Park acquired its first tortoises in 1965–1972, and numbers fluctuated between 3–11 adults. The private collection acquired two females and a male in 1986–1988. Tortoises were housed in a range of different indoor enclosures and some had access to outdoor enclosures in good weather. Eggs were incubated using a range of methods (see paper for details), with average temperatures ranging from 27–31°C.

    Study and other actions tested
  8. A replicated study in 1992–1993 in a captive breeding facility in the USA (Barzyk 1994) found that parrot-beaked tortoises Homopus areolatus reproduced successfully in captivity. A total of nine egg clutches were produced and nine of 21 eggs (43%) hatched successfully. At least two of the hatchlings survived for ≥13 months. In 1992, six wild tortoises (3 males, 3 females) and seven captive tortoises were brought to the indoor captive breeding facility. Two habitat enclosures measuring 7 x 2 feet were constructed, and two males and 4–5 females were put in each enclosure.

    Study and other actions tested
  9. A study in 1989–1992 in a captive setting [location unknown] (De Bruin & Zwartepoorte 1994) found that one of two female yellow-headed box turtles Cuora aurocapitata reproduced successfully in captivity. In 1992, two of three eggs produced by one female hatched successfully, and zero of three eggs from a second female hatched. Incubation lasted 64–66 days, and one hatchling was removed from the egg manually. The two hatchlings survived for at least 28 weeks. In 1989–1990, two pairs of turtles were acquired. Tanks contained a water basin (100 x 40 x 20 cm) and an island (40 x 20 cm), with water temperatures of 22°C, and air temperatures under a heating lamp at 27°C. One pair was housed together, and the second pair were kept separate. Males were introduced to both females for mating purposes. To induce egg laying, females were injected with calcium (at 60–80 mg/kg) subcutaneously in the rear leg, followed by 6 IU/kg of oxytocin intramuscularly one hour later. Eggs were placed in moist peat and incubated at 28°C at 95% humidity.

    Study and other actions tested
  10. A study in 1993 in captive conditions [location unknown] (Artner 1995) found that Reimann's snake-necked turtle Chelodina reimanni bred successfully in captivity. Captive female Reimann’s snake-necked turtles were observed breeding in captivity. Four female turtles laid two–three clutches each (6–15 eggs/clutch) in one year. After artificial incubation, 43 of 74 eggs (58%) hatched successfully. The authors report that the substrate material used did not affect egg development. At least one captive-born hatchling survived at least two years. Four female and two male turtles were kept in captivity. Eggs were collected after laying and artificially incubated at a constant temperature of 28°C on a substrate of dry sand, moist vermiculite, moist perlite, or a moist sand-peat mixture.

    Study and other actions tested
  11. A study in 1996–1999 in captive conditions in Vienna, Austria (Valentin & Gemel 1999) found that tricarinate hill turtles Melanochelys tricarinata bred successfully in captivity. Three female turtles laid 12 clutches (1–3 eggs/clutch). Six of 23 eggs (23%) hatched and at least four hatchlings survived at least two years and five months. Four male and three female adult turtles were housed in captive facilities. Mating occurred at temperatures above 28°C. Females were x-rayed to check for pregnancy. After being laid, eggs were artificially incubated at air temperatures of 27–31°C, 85–95% humidity and on a sand-earth substrate.

    Study and other actions tested
  12. A replicated study in 1986–1997 in an outdoor captive facility in north-western Madagascar (Pedrono & Sarovy 2000) found that ploughshare tortoises Geochelone yniphora bred successfully in captivity and captive-born individuals survived at least 8–9 years in captivity. Over 10 years a captive breeding facility produced 255 surviving ploughshare tortoises and the captive population increased in size each year. The first successful captive hatching was one year after the programme began. The authors reported that mortality in captive-born juveniles was rare. In 1986, eight male and 10 female adult ploughshare tortoises were brought to an outdoor captive facility. Eggs were left to hatch in situ and after emerging, hatchlings were placed in 1 m2 rearing enclosures until four years of age when they were moved to a larger 20 m2 enclosure.

    Study and other actions tested
  13. A study in 1997–2003 in a captive facility in Silhouette, Seychelles (Gerlach 2003; same experimental set-up as Gerlach 2011) found that some black mud turtle Pelusios subniger parietalis eggs hatched in captivity, but that chestnut-bellied mud turtle Pelusios castanoides intergularis eggs did not hatch in captivity. In the 1997–1998 and 1998–1999 breeding seasons, no black mud turtle eggs hatched in captivity, although clutches were laid. In 1999–2000, one of 18 eggs hatched (two clutches laid), in 2000–2001, nine of 23 eggs hatched (three clutches laid), in 2001–2002, twelve of 25 eggs hatched (three clutches laid) and in 2002–2003, six of 8 eggs hatched (clutch numbers not reported). In 1999–2003, no chestnut-bellied mud turtle eggs hatched although clutches were laid in 2000–2001 (three eggs laid), 2001–2002 (two eggs laid) and 2002–2003 (24 eggs laid). The authors reported that incubation humidity was too high for chestnut-bellied mud turtle eggs. In 1997–1998, five captive black mud turtles (one male, four females) and five chestnut-bellied mud turtles (two males, three females) were brought to a captive facility (see original report for husbandry details). In 1999, four of five black mud turtles died in captivity and were replaced with five captive black mud turtles (three males, two females). In 2000–2001, two further female captive black mud turtles were added. No details of incubation are provided.

    Study and other actions tested
  14. A study in 1999–2002 in naturally-vegetated outdoor captive enclosures in Silhouette Island, Seychelles (Gerlach 2003; same experimental set-up as Gerlach 2011) found that one female Seychelles giant tortoise Dipsochelys hololissa and one female Arnold’s giant tortoise Dipsochelys  arnoldi successfully bred in captivity. From 1999–2001, all of the 160 eggs laid by three female Arnold’s giant tortoises and all of the 47 eggs laid by a single female Seychelles giant tortoise in captivity were infertile. In 2002, three of at least 13 (23%) Arnold’s giant tortoise eggs (laid by one female) and two of 21 (10%) Seychelles giant tortoise eggs (laid by one female) hatched successfully in captivity. All successfully hatched eggs were artificially incubated. Eggs reburied in the ground did not hatch and eggs left in situ were predated by crabs. The authors reported that the Arnold’s giant tortoise offspring were thought to be Seychelles-Arnold giant tortoise hybrids. In 1997–1999, three male and three female Arnold’s giant tortoises, four male and two female Seychelles giant tortoises, and one juvenile Aldabra tortoise Dipsochelys dussumieri were brought to a captive facility. In 1999–2002, three female Arnold’s giant tortoises laid 21 clutches between them (6–16 eggs/clutch, two clutches with unknown clutch size) and one female Seychelles giant tortoise laid four clutches (14–21 eggs/clutch). In 2002, eggs were artificially incubated at 29–30°C.

    Study and other actions tested
  15. A study in 1991–2002 at Jersey Zoo, Jersey (Gibson & Buley 2004) found that Malagasy Flat-tailed tortoises Pyxis planicauda had limited success breeding in captivity. Females produced 2–3 eggs/season, though only three eggs hatched successfully over 11 years. One hatchling died after 18 months. Incubation periods were >213, 262 and 306 days. Two females and four males were obtained in 1991, and a further three females were obtained in 1997. Males were housed in individual enclosures (50 x 50 cm), and females were housed together (400 x 50 cm enclosure). Temperature, humidity and rainfall (from a sprinkler system) were moderated to replicate the wet/dry season cycle (see paper for details). Eggs were incubated in a bowl with dry vermiculite, inside a box containing damp vermiculite (1:1 with water by weight). The incubation box was subjected to the same seasonal conditions as the captive tortoises, but temperatures were increased to 30–31°C near the end of incubation.

    Study and other actions tested
  16. A replicated study in 1997–2000 in Italy (Mattioli et al. 2006) found that spider tortoises Pyxis arachnoides bred successfully in captivity. Females produced three clutches/year each of one egg/clutch, and 25% hatched successfully. All hatchlings survived to adult size. Tortoises were imported from Madagascar in 1997–1998 or were obtained from private breeders or other facilities. Reproduction was monitored in captivity over two years. Some data were obtained from private breeders.

    Study and other actions tested
  17. A study in 2001–2009 in a captive setting in Uttar Pradesh, India (Whitaker 2009) reported that red-crowned roof turtles Batagur kachuga bred successfully in captivity. Four females produced 1–5 clutches/year of 11–23 eggs, and hatching success ranged from 0–81%. In 2001, four female and two male turtles were acquired. They were quarantined for six months before being introduced to an enclosure with a large pond (30 x 15 m) with a number of other turtles of different species. In 2003–2009, the nesting mound was searched frequently, and eggs that were found were removed and incubated in plastic boxes with moist sand.

    Study and other actions tested
  18. A replicated, controlled, before-and-after study in 1998–2009 in Hainan Province, China (He et al. 2010) found that captive four-eyed turtles Sacalia quadriocellata began reproducing after six years after some individuals received hormone injections, but fertility and hatching success of eggs was low. Results were not statistically tested. In 2005–2009, nine of 84 eggs (11%) hatched successfully. In 2004–2008, five of 20 eggs (25%) from hormone injected females were fertile, and 11 of 21 eggs (52%) from females injected with a saline solution were fertile (numbers taken from table). In 2008–2009, three of 43 eggs (7%) from females kept in outdoor pools and given no injections were fertile. In 1998, twenty-eight female and 17 male turtles were acquired and kept in indoor pools (60 x 80 cm). In 2004–2007, eighteen females and 12 males were given luteinizing hormone-releasing hormone analogue (females: 8 µg/kg; males 4 µg/kg) and human chorionic gonadotropin (females: 1600 IU/kg; males 800 IU/kg). Hormones were injected into the hind leg muscles every 10 days up to 10 times/year. The remaining ten females and five males were injected with a saline solution. In 2007–2008, five females and five males were moved to an outdoor pond (10 m2), and in 2008–2009, eighteen females and 12 males were kept in the outdoor pond.

    Study and other actions tested
  19. A study in 1997–2009 in a captive facility in the Seychelles (Gerlach 2011, same experimental set-up as Gerlach 2003) reported that black mud turtles Pelusios subniger parietalis hatched in captivity, but that very few yellow-bellied mud turtles Pelusios castanoides intergularis hatched successfully in captivity. In 1997–2009, eighteen black mud turtles and three yellow-bellied mud turtles hatched successfully. The author reported that yellow-bellied mud turtles had a 70% mortality rate during hatching. Captive adult black mud turtles (1–3 males and 3–4 females) and yellow-bellied mud turtles (two males, three females) were held in captivity in 1997–2009 on Silhouette Island. Different pairing approaches were trialled for yellow-bellied mud turtles, including: keeping pairs together, keeping one female with two males, one male with two females, and rotating females between ponds with just males and just females. 

    Study and other actions tested
  20. A study in 1997–2011 in a captive facility in the Seychelles (Gerlach 2011, same experimental set-up as Gerlach 2003) reported that Arnold’s giant tortoises Dipsochelys dussumieri arnoldi and Seychelles giant tortoises Dipsochelys dussumieri hololissa bred successfully in captivity. In 2002–2006, forty Seychelles giant tortoises were reared from one female and one male and 140 Arnold’s giant tortoises were reared from two females and one male. In 1997–1998, six Seychelles giant tortoises (four males, two females) and six Arnold’s giant tortoises (three males, three females) were placed in captivity on Silhouette Island. In 2002, captive groups were reorganised, and all giant tortoises were put together in the same enclosure.

    Study and other actions tested
  21. A study in 2001–2009 at captive breeding facilities in Georgia and southern California, USA (Kuchling et al. 2013) reported that radiated tortoises Astrochelys radiata bred successfully in captivity. In 2001–2009, the captive breeding programmes produced at least 75 juvenile tortoises. Sixty-seven were female and eight were male. Incubation periods for those eggs that hatched in 2006–2009 ranged from 90–120 days. In 2001–2004, tortoises were maintained in a captive breeding facility in Georgia. Tortoises were then moved to a new facility in southern California, where they had access to both indoor and outdoor enclosures. One group of older, wild-caught tortoises were managed to maintain high genetic diversity (details not provided). Another group of captive-born tortoises could choose mates freely. In 2006–2009, eggs were incubated in vermiculite and water at a 2:1 ratio at 28.9°C or 30°C.

    Study and other actions tested
  22. A study in 2002–2009 in Florida, USA (Pearson 2013) found that when seasonal variation in temperature and humidity were recreated during incubation of captive Madagascar spider tortoises Pyxis arachnoides and flat-tailed tortoises Pyxis planicauda eggs, more than half of eggs hatched successfully. In 2002–2009, twenty-six of 50 (52%) spider tortoise eggs and 10 of 10 (100%) flat-tailed tortoise eggs hatched successfully. Of the spider tortoise eggs that failed to hatch, 71% were infertile. There was a large difference between the total incubation period (spider tortoises: 192–303 days; flat-tailed tortoise: 213–275 days) and the length of the incubation period after eggs began to develop (spider tortoises: 82–126 days; flat-tailed tortoise: 73–97 days; see paper for details). Tortoises were acquired in 2002 (numbers not given). Eggs were incubated at 31°C during the day and 26°C at night in vermiculite (1:1 ratio with water) for 8–12 weeks. Eggs were then removed from the incubator and kept at room temperature (20–24°C) for 6–8 weeks, and the vermiculite substrate was left to gradually dry out. Eggs were then returned to the warmer incubation conditions until hatching.

    Study and other actions tested
  23. A study in 1999–2011 in a captive breeding facility in Ampijoroa, Madagascar (Velosoa et al 2013) reported that Madagascar big-headed turtles Erymnochelys madagascariensis bred in captivity. In total, 94 live hatchlings were produced in three different years (2 in 2004, 52 in 2008, and 40 in 2011). The authors reported that most of the eggs laid were infertile, and that all eggs laid in three nests in 2009–2010 were infertile. The captive breeding programme started in 1999 and from 2011, the captive population comprised six adult males and three adult females. Males and females were put together for the breeding season but kept separately for the rest of the year.

    Study and other actions tested
  24. A study in 2001–2013 in Atlanta Zoo, Georgia, USA (Wyrwich et al. 2015) found that two Arakan forest turtles Heosemys depressa bred in captivity and at least one egg hatched from nine of the 11 clutches that were laid. Two captive-bred female Arakan forest turtles laid one clutch/year each for five and six consecutive years respectively. Hatching success ranged between 0–100% for the first female (2–9 eggs laid/clutch) and 13–66% for the second female (4–8 eggs laid/clutch). Of 19 offspring produced, 17 survived in captivity for 1–10 years. One of the adult females bred successfully after three years in captivity, and the second did so during the first year in captivity. The first female died after breeding complications in the sixth year of egg laying. A pair of adult Arakan forest turtles were acquired by Atlanta Zoo in 2001, and a second female was acquired in spring 2009 from Zoo Miami. Adults were maintained in outdoor enclosures during the warmer months of the year and individually indoors during the dry season (see original paper for details).

    Study and other actions tested
  25. A study in 2001–2015 in Texas, USA (Sirsi et al. 2016) reported that narrow-headed softshell turtles Chitra indica produced a single hatchling in captivity. After 14 years, a turtle raised in captivity laid a clutch of 26 eggs. Of the 26 eggs, one (4%) hatched successfully after an incubation period of 69 days, four (15%) completely developed but hatchlings failed to emerge, 10 (39%) failed during development, and 11 (42%) were infertile. The adult female was raised in a 7 x 5 m circular flow-through tank and then moved to a 5 x 2 x 1 m fibreglass tank. No nesting beach was available, and eggs were deposited in the water. Eggs were transferred to a 1:1 mixture of vermiculite and water and incubated at 28°C.

    Study and other actions tested
  26. A replicated study in 2004–2016 in captive facilities in the central dry zone of Myanmar (Platt et al. 2017) found that three captive populations of Burmese star tortoises Geochelone platynota bred in captivity. Over 14 years, hatching rates were 50–75% (no further details are provided) and total annual number of hatchlings produced increased from 168 individuals in 2008, to 2,142 individuals in 2016. Female hatchlings that had hatched before 2010 started laying eggs by 2016. The Burmese star tortoise was considered ecologically and functionally extinct in the wild during the 2000s. In 2004, three wildlife sanctuaries located within the tortoises presumed historical geographic range were established as captive assurance colonies, using confiscated juvenile, subadult and adult tortoises and some wild tortoises as the founder population (approximately 175 total tortoises of an equal sex ratio). Tortoises were housed in electric-fenced outdoor enclosures with shelter, food and water provided (see original paper for husbandry details). Nesting activity was monitored and eggs were left in situ to incubate and hatch.

    Study and other actions tested
  27. A study in 2012–2017 at Woodland Park Zoo, Washington, USA (Borek et al. 2018) found that one of two female Indochinese box turtles Cuora galbinifrons reproduced successfully in captivity. In 2013–2017, two females produced twelve clutches of 1–3 eggs, with an overall hatching success of 12%. All eggs that hatched came from one female. The average incubation period was 58 days. In 2012, one male and two female turtles were housed separately in glass fronted cages (91 x 135 cm) or concrete enclosures (97 x 183 cm) containing a substrate of soil, mulch and leaf litter, and bark and logs for cover. A water basin was also provided. Ambient temperatures were 25–28°C and humidity was kept at 75–80%. Males were introduced to the female cages for mating purposes. Eggs were moved to a container and suspended over perlite covered with water. A range of temperature regimes were used (see paper for more details), with temperatures ranging from 25.6–29.4°C.

    Study and other actions tested
  28. A study in 2013–2017 at the Smithsonian’s National Zoological Park, USA (Jarvis & Augustine 2018) found that when incubation temperatures were 26–27°C, one captive female Bourret’s box turtle Cuora bourreti produced eggs that hatched successfully, whereas at 28–29°C, no eggs hatched. When the incubation temperature was 26–27°C, four of four eggs hatched successfully, with incubation periods of 83–89 days. When the temperature was 28–29°C, zero of 15 eggs hatched successfully, and only three showed any signs of development. Incubation temperatures were 28–29°C in 2013–2016 and 26–27°C in 2017. Eggs were incubated in plastic containers, either partially buried in vermiculite (6:5 ratio with water), suspended over saturated vermiculite, or in the substrate in which they were laid (peat and soil mixture). One female and two males of wild origin were kept in captivity for over 10 years.

    Study and other actions tested
Please cite as:

Sainsbury K.A., Morgan W.H., Watson M., Rotem G., Bouskila A., Smith R.K. & Sutherland W.J. (2021) Reptile Conservation: Global Evidence for the Effects of Interventions for reptiles. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

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