Tag: geckos

Understanding Tokay Gecko Development: How Environment and Family Shape Captive Welfare

A recent study published in Herpetozoa offers valuable insights that could transform how we care for these lizards.

Tokay geckos are among the most recognisable and popular reptiles in the pet trade, celebrated for their vibrant colours and vocal nature. Despite their popularity and frequent breeding in captivity, many questions about how their early environment influences their development have remained unanswered.

A recent study published in the open-access journal Herpetozoa by Dr. Birgit Szabo of the University of Ghent has shed light on these critical factors, offering valuable insights that could transform how we care for these lizards.

When asked about what inspired this investigation, they explained:

“As a very popular pet, Tokay geckos are frequently bred in captivity. It was surprising to me how little we know about very basic environmental factors that can influence development. I am very passionate about improving captive conditions for reptiles and my study provides very important basic data.”

The research focused on both pre-natal factors, such as incubation temperature and humidity, and post-natal factors, specifically whether juveniles are raised in isolation or within a family group. Dr. Szabo monitored sixteen breeding pairs, tracking where females chose to lay their eggs and how the resulting thirty hatchlings grew over their first six months of life.

Captive-bred tokay gecko (*Gekko* *gecko*). Image credit: Birgit Szabo.

One of the most remarkable findings involved how temperature influences the sex of the geckos. Traditionally, Tokay geckos are understood to have a genetic sex-determination system with distinct sex chromosomes. However, the study revealed that higher incubation temperatures actually led to a higher proportion of male hatchlings.

Reflecting on this discovery, Dr. Szabo shared:

“I was most surprised about the effect of temperature on sex development. Tokay geckos are reported to possess sex chromosomes. Therefore, I did not expect that temperature would have an effect on sex development.

However, after consulting the literature I found that sex determination is quite labile in lizards, but this is a severely understudied area of research. So, I am quite excited to have found this effect and plan further research on this topic.”

Beyond sex ratios, incubation temperature also significantly affected developmental timing and physical size. Eggs kept at warmer temperatures had a shorter incubation period, yet they produced larger hatchlings with a greater snout-vent length. Interestingly, incubation humidity did not appear to have a noticeable impact on these physical outcomes.

Female tokay gecko curling around eggs attached to the cork back wall of the enclosure; Male next to one of his offspring; Tank set-up showing shelters on the back wall, branches, life plants and a water bowl. Image credit: Birgit Szabo.

The study also revealed that mother geckos actively chose nesting sites that offered warmer and less humid microclimates compared to other areas in the enclosure, demonstrating a preference for specific nesting conditions.

Managing such a detailed study was no small feat. Dr. Szabo noted,:

“The most challenging aspect was to set up the breeding and treatments after hatching. Tokay geckos are quite large lizards and need lots of space. Coordinating the different treatments under space limitations was quite the challenge.”

After hatching, the geckos were raised either alone or in family groups of varying sizes alongside their parents and siblings. Surprisingly, the post-natal social environment did not affect the young geckos’ growth, size, or body condition. Whether raised in isolation or in a busy family group, the juveniles grew at similar rates, suggesting that captive-bred Tokay geckos are highly adaptable in their early life stages.

These findings have direct implications for reptile husbandry, emphasising the need to provide captive reptiles with choices that replicate natural gradients. Dr Szabo remarked:

“A better understanding of the thermal and humidity requirements and preferences of reptiles is one of the most important aspects of the environment that is often suboptimal in active conditions.

I hope my research will highlight their importance and lead to improved enclosure design in the future.”

Ultimately, this study challenges long-held assumptions about reptile behaviour and social structures, proving that there is much more to these creatures than meets the eye. Dr. Szabo concluded:

“Reptiles are still viewed as asocial creatures but sociality exists in this animal group. Tokay geckos perform biparental care and protect both eggs and their offspring after hatching. Despite this knowledge, there is still much to learn about their social organisation especially in respect to welfare.”

Captive-bred tokay gecko (Gekko gecko). Videos taken by Dr. Birgit Szabo.

Original source:

Szabo B (2026) The influence of the pre- and post-natal environment on Tokay gecko (Gekko gecko, Squamata, Gekkonidae) development in captivity. Herpetozoa 39: 217-228. https://doi.org/10.3897/herpetozoa.39.e165454

Scientists discover bent-toed gecko species in Cambodia

Originally published by North Carolina Museum of Natural Sciences

A new species of bent-toed gecko (Cyrtodactylus phnomchiensis) has been described from Cambodia’s Prey Lang Wildlife Sanctuary by Wild Earth Allies Biologist Thy Neang in collaboration with North Carolina Museum of Natural Sciences‘ Herpetologist Bryan Stuart. This new species is described in ZooKeys.

The species was discovered by Thy Neang during Wild Earth Allies field surveys in June-July 2019 on an isolated mountain named Phnom Chi in the Prey Lang Wildlife Sanctuary when he encountered an unusual species of bent-toed gecko. “It was an extremely unexpected discovery. No one thought there were undescribed species in Prey Lang,” said Neang.

The geckos were found to belong to the C. irregularis species complex that includes at least 19 species distributed in south¬ern and central Vietnam, eastern Cambodia, and southern Laos. This is the first member of the complex to be found west of the Mekong River, demonstrating how biogeographic barriers can lead to speciation. Additionally, the geckos were unique in morphological characters and mitochondrial DNA, and distinct from C. ziegleri to which they are most closely related. Researchers have named the species Cyrtodactylus phnomchiensis after Phnom Chi mountain where it was found.

A new species of bent-toed gecko (*Cyrtodactylus phnomchiensis*) has been discovered in Cambodia’s Prey Lang Wildlife Sanctuary by Wild Earth Allies Biologist Thy Neang in collaboration with Bryan Stuart of the North Carolina Museum of Natural Sciences.
Photo by Thy Neang

Bent-toed geckos of the genus Cyrtodactylus are one of the most species-diverse genera of gekkonid lizards, with 292 recognized species. Much of the diversity within Cyrtodactylus has been described only during the past decade and from mainland Southeast Asia, and many of these newly recognized species are thought to have extremely narrow geographic ranges. As such, Cyrtodactylus phnomchiensis is likely endemic to Phnom Chi, which consists of an isolated small mountain of rocky outcrops (peak of 652 m elevation) and a few associated smaller hills, altogether encompassing an area of approximately 4,464 hectares in Kampong Thom and Kratie Provinces within the Prey Lang Wildlife Sanctuary, Cambodia.

The forest habitat in Phnom Chi remains in relatively good condition, but small-scale illegal gold extraction around its base threatens the newly discovered species. A second species of lizard, the scincid Sphenomorphus preylangensis, was also recently described from Phnom Chi by a team of researchers including Neang. These new discoveries underscore the importance of Prey Lang Wildlife Sanctuary for biodiversity conservation and the critical need to strengthen its management.

Habitat at Phnom Chi, the type locality of the newly described bent-toed gecko.
Photo by Thy Neang

Further, an assessment of C. phnomchiensis is urgently warranted by the IUCN Red List of Threatened Species (IUCN 2020) because of its small area of occupancy, status as relatively uncommon, and ongoing threats to its habitat.

“This exciting discovery adds another reptile species to science for Cambodia and the world. It also highlights the global importance of Cambodia’s biodiversity and illustrates the need for future exploration and biological research in Prey Lang,”
said Neang.

“When [Neang] first returned from fieldwork and told me that he had found a species in the C. irregularis group so far west of the Mekong River in Cambodia, I did not believe it. His discovery underscores how much unknown biodiversity remains out there in unexpected places. Clearly, Prey Lang Wildlife Sanctuary is important for biodiversity and deserves attention,”
said Neang’s co-author Stuart of the North Carolina Museum of Natural Sciences.

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Original source:

Neang T, Henson A, Stuart BL (2020) A new species of Cyrtodactylus (Squamata, Gekkonidae) from Cambodia’s Prey Lang Wildlife Sanctuary. ZooKeys 926: 133-158. https://doi.org/10.3897/zookeys.926.48671

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For more information on Wild Earth Allies, please visit: http://www.wildearthallies.org.

For more information on the North Carolina Museum of Natural Sciences, please visit:http://www.naturalsciences.org.

Tiger geckos in Vietnam could be the next species sold into extinction, shows a new survey

The endemic reptiles are already proposed to be listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora

While proper information about the conservation status of tiger gecko species is largely missing, these Asian lizards are already particularly vulnerable to extinction, as most of them have extremely restricted distribution. Furthermore, they have been facing severe declines over the last two decades, mostly due to overcollection for the international exotic pet market. Such is the case of the Cat Ba Tiger Gecko, whose tiny populations can only be found on Cat Ba Island and a few islands in the Ha Long Bay (Vietnam).

In their study, a Vietnamese-German research team, led by PhD candidate Hai Ngoc Ngo of the Vietnam National Museum of Nature in Hanoi, provide an overview of the evidence for domestic and international trade in tiger gecko species and update the information about the abundance and threats impacting the subpopulations of the Vietnamese Cat Ba Tiger Gecko in Ha Long Bay.

By presenting both direct and online observations, interviews and existing knowledge, the scientists point out that strict conservation measures and regulations are urgently needed for the protection and monitoring of all tiger geckos. The research article is published in the open-access journal Nature Conservation.

*Cat Ba tiger gecko (Goniurosaurus catbaensis) in its natural habitat. Photo by Hai Ngoc Ngo.*

Tiger geckos are a genus (Goniurosaurus) of 19 species native to Vietnam, China and Japan. Many of them can only be found within a single locality, mountain range or archipelago. They live in small, disjunct populations, where the population from Ha Long Bay is estimated at about 120 individuals. Due to demands in the international pet trade in the last two decades, as well as habitat destruction, some species are already considered extinct at the localities where they had originally been discovered.

However, it was not until very recently that some species of these geckos received attention from the regulatory institutions in their home countries, leading to the prohibition of their collection without a permit. Only eight tiger geckos have so far had their species conservation status assessed for the IUCN Red List. Not surprisingly, all of them were classified as either Vulnerable, Endangered or Critically Endangered. Nevertheless, none is currently listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which could be the only efficient and reliable method to monitor, regulate and police the trade of the species on a global scale.

“Tiger geckos are neither sufficiently protected by law nor part of conservation programmes, due to the lack of substantial knowledge on the species conservation status and probably due to the general lack of public as well as political interest in biodiversity conservation,” they explain. “To date, exact impacts of trade on the species cannot be identified, as data of legal trade are only recorded for species listed in the CITES Appendices”.

During their survey, the researchers tracked local traders in possession of wild-caught tiger geckos representing all five Vietnamese species en route to foreign exotic pet markets, mainly in the United States, the European Union and Japan. The species were also frequently found to be sold in local pet shops in Vietnam, as well as being offered via various online platforms and social media networks like Facebook.

Having spoken to local dealers in Vietnam, the team found the animals were traded via long and complex chains, beginning from local villagers living within the species’ distribution range, who catch the geckos and sell them to dealers for as little as US$4 – 5 per individual. Then, a lizard either ends up at a local shop with a US$7 – 25 price tag or is either transported by boat or by train to Thailand or Indonesia, from where it is flown to the major overseas markets and sold for anywhere between US$100 and 2,000, depending on its rarity. However, many of these delicate wild animals do not arrive alive at their final destination, as their travels include lengthy trips in overfilled boxes under poor conditions with no food and water.

Indeed, although the researchers reported a large quantity of tiger geckos labelled as captive-bred in Europe, it turns out that their availability is far from enough to meet the current demands.

In conclusion, the team provides a list of several recommendations intended to improve the conservation of the Asian geckos: (1) inclusion of all tiger geckos in the Appendices of CITES; (2) assessment of each species for the IUCN Red List; (3) concealment of any currently unknown localities; and (4) improvement/establishment of coordinated ex-situ breeding programmes for all species.

*Signboard handed over to the Ha Long Bay Management Department to point to the threats and conservation need of the Cat Ba tiger gecko in English and Vietnamese languages.*

The inclusion of all tiger gecko species from China and Vietnam in CITES Appendix II was recently proposed jointly by the European Union, China and Vietnam and is to be decided upon at the Conference of the parties (CoP18) in May-June 2019, held in Sri Lanka.

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Original source:

Ngo HN, Nguyen TQ, Phan TQ, van Schingen M, Ziegler T (2019) A case study on trade in threatened Tiger Geckos (Goniurosaurus) in Vietnam including updated information on the abundance of the Endangered G. catbaensis. Nature Conservation 33: 1-19. https://doi.org/10.3897/natureconservation.32.33590