# Tortoise — Facts, Threats & Conservation

*Family Testudinidae*

> Tortoises (family Testudinidae) are fully terrestrial reptiles found across warm regions worldwide; over 86% of species are threatened or extinct, driven by illegal trade, habitat loss, and the pet industry.

**IUCN status:** Varies by species — many Critically Endangered (IUCN)  ·  **WARN range:** Africa, Asia, South America, North America, Europe, Madagascar, Galapagos Islands, Aldabra Atoll

## Quick facts
| Fact | Value |
| --- | --- |
| Family | Testudinidae |
| Number of species | ~40–60 living species |
| Shell type | High-domed carapace of fused bone and keratinous scutes |
| Diet | Primarily herbivorous (grasses, leaves, fruit) |
| Lifespan | 50–100+ years; giant species may exceed 150 years |
| Smallest species | Speckled padloper (Chersobius signatus) — under 12 cm |
| Largest species | Aldabra giant tortoise — up to 250 kg |
| Incubation | 70–120 days; sex determined by nest temperature |
| Habitat | Deserts, savannas, dry forests, Mediterranean scrub, tropical margins |
| CITES status | All species listed: most threatened on Appendix I; remainder on Appendix II |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Reptilia
- **Order:** Testudines
- **Suborder:** Cryptodira
- **Family:** Testudinidae
- **Genera:** ~11–16 (incl. Chelonoidis, Aldabrachelys, Astrochelys, Testudo, Gopherus, Stigmochelys, Kinixys)

## Conservation status
- **Status:** Varies — many Critically Endangered; 86%+ of family threatened or extinct
- **Population:** Varies widely by species; some (e.g. Aldabra giant tortoise) exceed 100,000; others number in the hundreds
- **Trend:** Decreasing across the majority of species
- **Assessed:** 2025
- **CITES:** Appendix I (most threatened species) and Appendix II (all remaining Testudinidae)
- The IUCN Tortoise and Freshwater Turtle Specialist Group (TFTSG) is the Red List Authority for all chelonians. A 2025 Nature Communications study (PMC12318056) found 54% of all chelonian species threatened, with Testudinidae having the highest Average Threat Level (86.2% threatened or extinct) of any turtle family.

## Key facts: Tortoise
- Tortoises are among the longest-lived vertebrates on Earth — giant species routinely exceed 100 years and some may surpass 150.
- The family Testudinidae has the highest Average Threat Level of any chelonian family, with over 86% of species classified as threatened or extinct.
- Illegal collection for the pet trade and bushmeat markets is the single largest direct driver of tortoise population collapse, particularly in Asia and Madagascar.
- Temperature-dependent sex determination makes tortoises highly vulnerable to climate change — rising nest temperatures skew sex ratios and can collapse breeding populations.
- Captive breeding has produced remarkable recoveries: the Española tortoise rebounded from 15 survivors to a current island population of over 3,000 naturally reproducing individuals in the Galapagos.
- Most tortoise species are covered by CITES — the most threatened are on Appendix I, banning all commercial trade, while the remainder are on Appendix II requiring export permits.

## What is a tortoise, and how is it different from a turtle?
The word 'tortoise' refers specifically to members of the family Testudinidae — fully terrestrial reptiles that never voluntarily enter water beyond shallow puddles for drinking or cooling. All tortoises are technically turtles (order Testudines), but not all turtles are tortoises. The key anatomical clues lie in the limbs and shell. Tortoises bear thick, pillar-like hind legs resembling those of an elephant, each digit reduced to two or fewer phalanges, granting stability on rough ground rather than propulsion through water. Their shells are typically high-domed — unlike the flat, streamlined carapaces of aquatic species — providing structural rigidity against predator bites. Internally, the carapace is composed of around 50 to 60 fused bones, including modified ribs and vertebrae, overlaid by keratinous scutes arranged in a consistent pattern: five vertebral scutes along the midline, four pairs of costal scutes on the flanks, and twelve pairs of marginal scutes around the rim. The shell also acts as a calcium reserve during egg production and absorbs solar heat to regulate body temperature, since tortoises are ectotherms with no internal heat generation. When threatened, most species can retract the head, limbs, and tail fully inside the shell — an emergency refuge that has served the group for millions of years.

## Where do tortoises live, and what do they eat?
Testudinidae occupy an unusually broad ecological range. Species are native to sub-Saharan Africa, the Mediterranean basin, the Middle East, South and Southeast Asia, and the Americas from the southern United States to northern Patagonia. Island giants have evolved independently on Madagascar, the Galapagos Archipelago, and Aldabra Atoll in the Indian Ocean. Across these regions, tortoises inhabit deserts, semi-arid scrublands, dry savannas, Mediterranean maquis, tropical dry forests, and even humid rainforest margins — anywhere that seasonal warmth can sustain an ectotherm. Burrowing is common in arid species: the desert tortoise of North America digs tunnels more than a metre deep to escape lethal summer heat and winter cold, spending up to 95 percent of its life underground. Diet is overwhelmingly herbivorous — grasses, leaves, flowers, cacti, and fallen fruit form the bulk of intake — though most species opportunistically consume fungi, carrion, or invertebrates to supplement minerals. The giant tortoises of the Galapagos act as ecosystem engineers, dispersing seeds of large-fruited plants across islands and grazing vegetation in patterns that maintain open habitat for other species. Water is extracted chiefly from food, and some arid-adapted tortoises can store water in an accessory bladder beneath the shell.

## How do tortoises reproduce, and why does that make conservation harder?
Tortoise reproduction is built for longevity, not speed — a strategy that works well in stable environments but becomes a serious vulnerability when populations are driven down quickly. Sexual maturity is typically reached only after a decade or more of growth; in large species such as the Aldabra giant tortoise, females may not produce their first clutch until their late teens or twenties. Courtship involves males competing through shoving contests and ritual head-bobbing; in some species males possess a forwardly projecting gular scute — an extension of the lower shell — used as a weapon to flip rivals. Females excavate a flask-shaped nest with their hind feet, depositing between 1 and 30 eggs depending on species size, then abandon the nest entirely. Incubation takes 70 to 120 days at naturally fluctuating soil temperatures. Crucially, sex is not determined by genetics but by nest temperature — a phenomenon called temperature-dependent sex determination (TSD). Warmer nests produce more females; cooler nests more males. As average soil temperatures rise with climate change, researchers have documented skewing sex ratios in multiple species, including Galapagos giant tortoises, a demographic shift that can eventually limit reproduction even in populations that appear numerically stable. Hatchlings emerge with soft shells and face high predation from introduced mammals. Combined with the species' slow maturation, the loss of even a small number of breeding adults can push a local population below recovery threshold for decades.

## Why are so many tortoise species endangered?
A 2025 Nature Communications study found that 54 percent of all chelonian species now face extinction risk, and within Testudinidae the situation is even more severe: over 86 percent of species are threatened or already extinct, the highest average threat level of any turtle family. Several converging pressures explain this crisis. First, the illegal wildlife trade. Tortoises are captured en masse for the international pet market — rare island species can fetch thousands of dollars per individual as status symbols — and for food and traditional medicine, particularly across Asia. A 2023 anti-poaching operation in Madagascar rescued more than 3,200 critically endangered radiated, ploughshare, and spider tortoises that had been seized for export. Second, habitat destruction. Agricultural expansion, charcoal production, and urban development are eliminating the dry forests and savanna woodlands that many species depend on. Third, invasive species introduced by humans — rats, pigs, cats, and goats — prey on eggs and hatchlings or strip away the vegetation tortoises need to survive. Fourth, climate change threatens to feminise populations through TSD disruption and reduce the availability of food plants during increasingly intense droughts. The illegal pet trade and exploitation for food remain the largest direct drivers globally, with Asia identified as the epicentre of the extinction crisis — harbouring 32 of the 66 most critically threatened chelonian species.

## What conservation efforts are protecting tortoises, and can they recover?
The evidence from some of the most desperate cases shows that tortoises can recover — but only with sustained, well-resourced intervention. The Española giant tortoise of the Galapagos is the standout example: reduced to just 15 individuals in the 1960s, a captive breeding programme produced more than 2,000 offspring that were repatriated to the island. Today, over 3,000 Española tortoises breed naturally there. The Aldabra giant tortoise, once hunted to dangerously low numbers in the 19th century, rebounded to more than 100,000 individuals after harvesting was halted and the atoll was given protected status. Legal frameworks provide an essential foundation. All Testudinidae species are listed on CITES appendices — the most threatened on Appendix I (commercial trade banned), the remainder on Appendix II (requiring verified export permits). Targeted captive breeding centres, invasive predator eradication on island nesting sites, and community engagement with local populations near tortoise habitat have all demonstrated measurable impact. Genomic tools now allow conservationists to identify the island-of-origin of confiscated individuals and to detect surviving carriers of ancestral genetics in hybrid populations, enabling precise reintroduction planning. However, the sheer number of species in crisis, combined with the slow generational pace of tortoise recovery, means that preventing the initial collapse — through better trade enforcement and habitat protection — remains far more cost-effective than rescue after the fact.

## Pet Tortoise Species Guide
From the popular Hermann's and Russian tortoises to the Greek, Sulcata, Leopard, Red-footed, Indian Star and Marginated — explore the tortoise species most often kept as pets, with adult size, lifespan, conservation status, common health issues and an honest look at the decades-long commitment each one needs.

Full species library (8 guides): https://worldanimalrescuenetwork.org/wildlife-guides/tortoise#breeds

- **Hermann's Tortoise:** One of the most popular pet tortoises — a hardy Mediterranean species that hibernates. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/hermanns-tortoise
- **Russian Tortoise:** A small, hardy burrowing tortoise — popular but heavily collected from the wild. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/russian-tortoise
- **Greek Tortoise:** The 'spur-thighed' tortoise — a Vulnerable Mediterranean species with spurs on the thighs. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/greek-tortoise
- **Sulcata Tortoise:** The giant of the pet trade — cute as a hatchling, but grows to the size of a coffee table. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/sulcata-tortoise
- **Leopard Tortoise:** A large grassland grazer with a beautifully spotted, high-domed shell. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/leopard-tortoise
- **Red-footed Tortoise:** A colourful, sociable South American tortoise of humid forest edges. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/red-footed-tortoise
- **Indian Star Tortoise:** A stunning star-patterned tortoise — and one of the most heavily trafficked in the world. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/indian-star-tortoise
- **Marginated Tortoise:** The largest European tortoise, with a flared, skirt-like rear of the shell. — https://worldanimalrescuenetwork.org/wildlife-guides/tortoise/marginated-tortoise

## What WARN does
WARN does not currently run field projects specifically for tortoises, as WARN's rescue and conservation partnerships are focused in Indonesia, Malaysia, Pakistan, Brazil, and Colombia. This guide is offered as free educational content to support public awareness of one of the world's most threatened reptile groups. Understanding why ancient animals like the tortoise are vanishing — and what trade policies and habitat decisions drive that loss — matters everywhere, regardless of where on the globe the action is taken.

Tortoises have survived for tens of millions of years — but they cannot outpace the modern threats of illegal trade and habitat loss without human intervention. Supporting WARN helps fund the habitat protection work that gives ancient animals like these a fighting chance.

## Frequently asked questions: Tortoise
### How long do tortoises live?
Lifespans vary considerably by species, but tortoises are among the longest-lived vertebrates on Earth. Most medium-sized species live between 50 and 100 years in the wild. Giant species — Aldabra and Galapagos tortoises — routinely exceed 100 years and credibly documented individuals have reached 150 years or more. Jonathan, a Seychelles giant tortoise living on the island of St. Helena, is believed to have hatched around 1832, which would make him roughly 193 years old in 2026 and the oldest known living land animal. Their exceptional longevity is linked to slow metabolisms, low oxidative stress, and a capacity for cellular repair that scientists are actively studying for insights into ageing.

### Can a tortoise come out of its shell?
No. A tortoise's shell is a permanent, living part of its body — not a detachable house. The carapace (upper shell) and plastron (lower shell) are formed from around 50 to 60 fused bones including modified ribs and vertebrae, all supplied with nerves and blood vessels. Tortoises can feel pressure on their shells and the shell can bleed if cracked. What they can do is retract their head, limbs, and tail inside the shell when threatened.

### What is the difference between a tortoise and a turtle?
All tortoises are turtles (order Testudines), but the term 'tortoise' specifically refers to members of the family Testudinidae — fully land-dwelling reptiles with high-domed shells, stumpy elephantine legs, and no webbing between the toes. Aquatic and semi-aquatic turtles have flatter shells and webbed or flippered feet adapted for swimming. In everyday British English, 'tortoise' means a land species while 'turtle' usually refers to sea turtles; in North American English the lines blur more.

### Why are tortoises so slow?
Tortoises' slow movement is a by-product of their anatomy and energy budget, not a flaw. Their heavy, domed shell and thick columnar legs are built for stability and load-bearing rather than speed. As ectotherms, they rely on ambient heat to fuel muscle activity, which limits burst performance. More importantly, their entire life strategy is built around conserving energy: a low metabolic rate allows them to survive on sparse vegetation, tolerate long dry seasons, and channel resources into longevity and shell maintenance rather than rapid locomotion.

### Are tortoises good pets?
Tortoises have complex welfare needs that make them challenging pets requiring serious long-term commitment. They can live 50 to 100-plus years, meaning they will outlive most owners. They need species-appropriate temperatures, UV-B lighting, correct humidity, varied plant-based diets, and adequate space to roam. Many species available in the pet trade were illegally wild-caught, contributing directly to population declines. Prospective keepers should research local laws, obtain only captive-bred animals from licensed breeders, and be prepared for a decades-long commitment.

### How many tortoise species are there?
Depending on the taxonomic authority, the family Testudinidae contains approximately 40 to 60 recognised living species across 11 to 16 genera. The number fluctuates as molecular studies reveal cryptic species or synonymise previously separate taxa. Well-known species include the Galapagos giant tortoise (Chelonoidis niger), the Aldabra giant tortoise (Aldabrachelys gigantea), the radiated tortoise (Astrochelys radiata), the Russian tortoise (Testudo horsfieldii), and the leopard tortoise (Stigmochelys pardalis).

## Sources
- [IUCN SSC Tortoise and Freshwater Turtle Specialist Group Red List](https://iucn-tftsg.org/red-list/)
- [Global assessment of current extinction risks and future challenges for turtles and tortoises — Nature Communications (2025)](https://www.nature.com/articles/s41467-025-62441-2)
- [Global assessment of current extinction risks and future challenges for turtles and tortoises — PMC full text](https://pmc.ncbi.nlm.nih.gov/articles/PMC12318056/)
- [IUCN SSC Tortoise and Freshwater Turtle SG Report 2024–2025](https://iucn.org/sites/default/files/2025-04/2024-2025-iucn-ssc-tortoise-and-freshwater-turtle-sg-report_publication.pdf)
- [Tortoise | Britannica](https://www.britannica.com/animal/tortoise)
- [Testudinidae — Animal Diversity Web](https://animaldiversity.org/accounts/Testudinidae/)
- [CITES Appendices — U.S. Fish & Wildlife Service](https://www.fws.gov/international-affairs/cites/cites-appendices)
- [Global Conservation Status of Turtles and Tortoises — USGS](https://www.usgs.gov/publications/global-conservation-status-turtles-and-tortoises-order-testudines)

---
Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/tortoise