Return to Nature: 27 Leopard Tortoises Released into the Wild in South Africa

South Africa is home to thirteen different tortoise species. With a carapace over 50 centimeters in length and weighing more than 30 kilograms, the leopard tortoise (Stigmochelys pardalis) is among the largest members of this group. Due to their wide distribution – leopard tortoises inhabit large parts of southern and eastern Africa, from dry semi-deserts and savannahs to more humid regions – the armored reptiles are currently classified as being of “least concern (LC)” by the International Union for Conservation of Nature (IUCN). “However, tortoises in South Africa are still exposed to numerous threats,” explains Dr. Melita Vamberger from the Senckenberg Natural History Collections Dresden, and she continues, “The greatest threats include illegal trade and possession, use as a food source and in traditional medicine, fatal accidents at electric fences, and the progressive loss and destruction of their habitat as a result of urban sprawl, overgrazing, and slash-and-burn agriculture.”

Together with a team of South African and German researchers, the scientist from Dresden has expanded a genetic reference database for leopard tortoises and tested it in practice. The study involved animals from the South African province of KwaZulu-Natal and from Eswatini. In addition, the researchers added genetic data from 50 wild tortoises from these regions to the database. “The illegal trade in leopard tortoises is widespread. Over the past twenty years, an increasing number of tortoises have been taken into rescue stations and zoos, resulting in the accumulation of large populations – often without reliable knowledge of their original provenance,” explains Vamberger.

The rescue station in KwaZulu-Natal, for example, took in over 100 leopard tortoises between 2016 and 2025 and had to turn away additional animals due to lack of space, while a facility in Durban even registered more than 300 animals in the same period.

“The handling of these tortoises is controversial, as they are mostly illegally collected, kept, abandoned, or escaped individuals. There are really only three options: life-long captivity, release into the wild, or euthanizing,” adds the turtle expert. “As leopard tortoises have a very long lifespan and have high demands in terms of space, food, and medical care, keeping them permanently is only feasible to a limited extent. Fortunately, healthy animals will not be euthanized. Releasing them back into the wild is therefore often the only sensible solution.”

However, previous releases into the wild often took place without clear guidelines and accompanying follow-up checks, which meant that risks such as overpopulation, migration to unsuitable habitats, genetic mixing, disease transmission, and uncertain survival prospects were insufficiently considered.

According to the new study, in terms of species conservation it is of crucial importance to know an animal’s precise region of origin – this is the only way to decide how and where it can be sensibly reintroduced into the wild.

The genetic analysis yielded surprising results: Only a single leopard tortoise from the rescue station in KwaZulu-Natal could be genetically assigned to this region. “This shows the extent to which illegal trade, relocation, and private captivity are disrupting the natural distribution patterns of this species,” adds Vamberger.

Animals whose regional origins could be genetically determined with certainty were systematically rehabilitated and eventually repatriated in suitable locations.

To date, 27 of the 50 leopard tortoises have been released back into the wild. At first, the animals underwent a “soft release” phase lasting around six months – they were initially kept in escape-proof enclosures in their future habitat to observe how well they adapted to the environment before being permanently released. “Depending on their genetic origin, the tortoises were moved to different regions: One group was released in a private reserve in the Eastern Cape Province, while others were placed in protected areas in the Northern Cape, Free State, and Limpopo provinces,” explains Vamberger.

The research team’s results show that the expanded genetic database can be used to reliably determine the region whence individual tortoises originate. “This is crucial for returning them to the proper location and strengthening existing populations in a meaningful way. Our study also reveals that many of the tortoises in rescue stations originally come from distant regions. This clearly shows how widespread illegal trade and transportation are. To counteract this, there needs to be better cooperation between nature conservation authorities, rescue stations, and research institutions – ideally not just within South Africa but across national borders,” adds Vamberger in conclusion.

Publication: Armstrong, A.J., Kropff, A.S., Kotze, A. et al. Back Home: first successful geographical assignment of rehabilitated leopard tortoises Stigmochelys pardalis using a conservation genetic database. Conserv Genet 27, 41 (2026). https://doi.org/10.1007/s10592-026-01773-y