Burmese Star Tortoise (Geochelone platynota) Fact Sheet: Reproduction & Development

Mating

• Seasonality
• Most common June to September, but occurs throughout the year in managed care (Thanda Swe 2004, cited by Platt et al. 2011; Platt et al. 2017)
• Behavior
• Male may follow female for about 30 min prior to copulation (Thanda Swe 2004, cited by Platt et al. 2011)

General

• Sexual maturity
• Approximately 6 to 8 years of age (Platt et al. 2017; Praschag et al. 2020)
• Sex ratios
• Influenced by temperature during egg incubation (i.e., temperature-dependent sex determination) (Kuchling et al. 2011)
• Balanced sex ratio at approximately 30°C (86°F)

Egg laying

• Eggs laid from late September to mid-May (observations from conservation breeding groups in Myanmar’s Dry Zone) (Kalyar Platt et al. 2014; Platt et al. 2017)
• Thanda Swe (2004) noted egg laying from mid-October through late February
• Egg description
• Large and elongate (Smith 1931)
• 55 x 40 mm (2.2 x 1.6 in) (Smith 1931)
• White (Kalyar Platt et al. 2014; Platt and Platt 2020)
• Nest
• Shallow hole in the ground (14 x 15 x 9 cm) (Thanda Swe 2004, cited by Platt et al. 2011; Kalyar Platt et al. 2014)
• Clutch size (observations from conservation breeding groups in Myanmar’s Dry Zone)
• 4 to 7 eggs per clutch, on average (range typically 1 to 11) (Kuchling et al. 2011; Thanda Swe 2004, cited by Platt et al. 2011; Kalyar Platt et al. 2014)
• Possibly up to 16 eggs per clutch (Kuchling et al. 2011)
• Clutch size increases with female body size (Platt et al. 2011)
• Platt et al. (2019) observed a large female lay 26 eggs in 4 clutches (Table 1)
• Interclutch interval
• Females lay 1 to 4 clutches per breeding season (Thanda Swe 2004, cited by Platt et al. 2011; Platt et al. 2017; Platt et al. 2019)
• Possibly up to 6 clutches for large females; needs confirmation (Praschag et al. 2020; S.G. Platt, personal communication, 2022)

Incubation and hatching

• Incubation period
• 197 days, on average (range: 172 to 251) (Thanda Swe 2004, cited by Platt et al. 2011)
• Weight at hatching
• About 15 g (0.5 oz) (S.G. Platt, personal communication, 2022)
• Timing of hatching
• In Myanmar, mid-May to late July (Thanda Swe 2004, cited by Platt et al. 2011)
• Coincides with onset of wet season

Wild populations

• Not well known; possibly more than 50 years, maximum (Praschag et al. 2020)
  • More research needed

Managed care

• 9.3 years (male, female data combined) (AZA 2024)

Survival rates

• Juvenile survival in the wild likely low; typical of long-lived tortoises (Platt and Platt 2021)
• Hatching and post-release survival of head-start programs high (Kalyar Platt et al. 2014; Platt and Platt 2017; Platt and Platt 2020)

Predators

• Wild pig, Sus scrofa (Platt and Platt 2020; Platt et al. 2021)
• Eurasian golden jackal, Canis aureus (Platt et al. 2015; Platt et al. 2021)
• Rats (Platt et al. 2015; Platt et al. 2017)
• Possible predators (direct observation still needed)
  • Snakes and birds (Platt et al. 2021)
  • Large cats (Platt et al. 2018)

Accidental death

• Some individuals injured or die during wildfires (Platt et al. 2001; Platt et al. 2003)

Diseases (non-comprehensive list)

• Mycoplasma (N. Haislip, personal communication, 2022)
• Ranavirus detected in G. platynota in managed care (Johnson et al. 2008)

Parasites (non-comprehensive list)

• Few studies (Platt et al. 2011)
• Ticks (Robbins and Platt 2000)
• Roundworms, tapeworms, flukes, and protozoans known from managed care (Kalyar Platt et al. 2014)

A Burmese Star Tortoise lays eggs at a conservation colony in Myanmar.

Females typically lay 4 to 7 eggs per clutch.

Image credit: Steven G. Platt, © WCS/TSA Myanmar Turtle Program. All rights reserved. Used with permission.

In Myanmar, egg hatching coincides with the onset of the wet season.

Image credit: Me Me Soe, © WCS/TSA Myanmar Turtle Program. All rights reserved. Used with permission.

Hatchlings seek cover to avoid rats, wild pigs, and other predators.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.