The El Hierro giant lizard
If you've been to the Canary Islands, you've seen lizards. They bask on terrace walls and stone walls, and by the time you look, they've already vanished into a crack.
El Hierro is home to a relative of theirs that, for much of the 20th century, was written off as gone. This is the lagarto gigante de El Hierro, the El Hierro giant lizard.
If you want to see one, don't look for it on the cliffs. Its only known wild population lives on almost inaccessible cliff faces, and the islet where it was successfully reintroduced can only be visited for scientific or conservation purposes. You can see the giant lizard at the recovery centre that is part of the Ecomuseo de Guinea, in the municipality of Frontera. Check visiting arrangements and prices on the operator's website, because the operator itself warns that the schedule may change.
But this story is not only about a lizard. It is also about how science can lose a species while a handful of people know all along where it lives.
A lizard thought to be extinct
Archaeological finds show that the giant lizard once lived across almost the whole island, except in the misty mountain forests, where it was too damp for it to regulate its body temperature. Radiocarbon dates from remains found at La Dehesa suggest that it was still relatively abundant in the second half of the 19th century, which is why the 2026 recovery plan says the impact of the island's aboriginal people may have been merely token. The drastic decline began with the arrival of Europeans in the 15th century, mainly because of introduced rats and cats.
Science first came across it in August 1889, when the first specimens were collected on the Roque de Salmor, a rocky islet off the coast. That same year Franz Steindachner described the species and named it after his student, the Austrian geologist Oscar Simony (1852-1915), who had caught the specimens. Today its scientific name is Gallotia simonyi.
Then the Salmor population disappeared. According to the 2002 edition of the Spanish Red Book, this happened around 1935; according to the 2026 plan, by the 1940s. Both blame collectors. We don't know the exact year, but we do know the consequence: the species was considered extinct.
Plasticine droppings in a matchbox
Some people, however, knew it was not extinct. At the southern end of the Risco de Tibataje, on the Fuga de Gorreta, a small population lived on that only the goatherds knew about. Its existence came to light through enquiries made by the researcher A. Salvador in 1971.
In 1974 Werner Bings, a German architect and reptile breeder, set off for El Hierro, building on Salvador's data and the shepherds' knowledge, to find out whether the species was still alive and, if so, to catch a live pair he could breed in Germany.
According to a 2000 book by the Canary Islands Government and the Cabildo, Bings brought just one clue: a plasticine replica of the lizard's droppings in a matchbox, along with a photo of the Gran Canaria lizard. The shepherd Juan Machín recognised it, and Bings hired him to catch the lizards.
While Bings was away, Juan Machín and his grandson, Juan Pedro Pérez, caught a pair at a spot on the Fuga de Gorreta that the book calls Paso el Pino. The plan was to take them abroad, but that never happened: the government's representative on the island, Celestino Guillén Martín, and the head of the forest rangers, Zósimo Hernández Martín, stepped in. According to an account quoted in the book, the two lizards were taken back and released on the cliff.
The following year, Bings and Wolfgang Böhme, head of the herpetology section at the Museum Alexander Koenig in Bonn, announced that a small relict population was living on the Fuga de Gorreta. Their paper appeared in 1975 in the journal Salamandra.
That is why some sources give 1974 as the year of the rediscovery and others 1975. The simplest way to put it: in 1974 a shepherd and his grandson caught a pair, and in 1975 science confirmed it.
Perico, the shepherd's grandson
The grandson's name was Juan Pedro Pérez Machín, known on the island as Perico. He stayed with the lizards: a 2026 scientific paper, whose first author is the head of the breeding centre, thanks him "in memoriam" for his daily work with the giant lizards kept at the centre. The breeding centre, the Parque Zoológico, now bears his name.
On 23 March 2026, the Cabildo de El Hierro presented his family with a telegram from King Felipe VI praising Perico's work to protect the giant lizard. On the same day, the species' new recovery plan was published in the Canary Islands' official gazette.
What we know for sure about the giant lizard
The only known wild population lives on the Fuga de Gorreta, on the almost inaccessible cliffs in the north-west of the island, roughly between 80 and 400 metres above sea level.
Adults can exceed 500 millimetres in length, tail included. It is a stocky, brownish-black animal with two rows of yellow spots along its flanks, which are not always visible. It is mainly herbivorous and eats only a small proportion of animal food.
On the Roque Chico de Salmor, an unusual association has been observed: the lizards pick grasshoppers out of the food regurgitated by yellow-legged gulls and out of their pellets.
Females lay their eggs between June and July, an average of 8.8 in captivity; the hatchlings emerge at the end of summer and reach sexual maturity at 3 to 4 years of age.
Its close relatives are the giant lizards of La Gomera and Tenerife, and scientists call the three together the "simonyi group". On the island, it shares the role of El Hierro's symbol with the sabina juniper. Both the Canary Islands catalogue of protected species and the Spanish catalogue of threatened species list it as "en peligro de extinción", that is, in danger of extinction.
Breeding, a mudslide and reintroduction
Captive breeding began in 1985 at a temporary station in Frontera, led by Carlos Naeslund, and a year later it was already a success. In 1995, co-funded by an EU LIFE project, the breeding and research centre was set up, and it has been open to visitors ever since. The first recovery plan was approved in 2004.
In January 2007, torrential rain set off a slide of mud and rocks that buried part of the Guinea breeding facility. A total of 184 lizards died. In 2013 new terraria were built at El Matorral, further away from the cliffs.
According to the 2026 scientific paper, 1267 hatchlings were produced between 2006 and 2024, in the years covered by the data. In 2024, 98 hatchlings emerged from the eggs of 15 females, and one female set a record with 19 eggs. Before release, the young lizards are taught to recognise their predators, birds of prey and feral cats.
According to the 2026 plan, the first reintroductions went to three sites: the Roque Chico de Salmor, La Dehesa and El Julan. It only worked on the islet, with 21 lizards in 1999 and 15 a year later, 36 in all. The Roque Chico de Salmor is a tiny rock islet about 40 metres high, 0.8 kilometres off the coast, and according to the plan it is completely free of introduced predators. At La Dehesa 110 lizards were released and at El Julan 248; by the 2007 survey, roughly 2 and 4 were left, respectively. The plan puts the failure down mainly to cats.
At the end of 2013, 32 lizards were released at Punta de Agache in the north and 35 at Punta de Arelmo; at the end of 2016, 46 went to Punta de Miguel in the south-east; and in November 2020 another 50 went to Agache. According to RTVC, another 71 lizards were released at Agache in November 2024, the first release in four years.
What we don't know: how many giant lizards live in the wild
There is no precise answer today, and the researchers themselves say so.
The figures in the sources cannot be compared, because they were produced with different methods, in different areas and in different years, so we only give them together with their source and year. The 2026 plan's reference estimate, citing Trujillo's 2008 work, is 345 lizards on 15.25 hectares of the Fuga de Gorreta, but its uncertainty range runs from 143 to 738. The 2026 scientific paper gives 354 lizards for the Risco de Tibataje in 2007 and 834 in 2019, and states in the same place that the surveys are not strictly comparable, so the size of the population and its trend cannot be determined precisely. In 2002, the Spanish Red Book put the number at about 250 individuals, based on the two reliable surveys available at the time.
The most recent survey of the Roque Chico de Salmor cited by the plan dates from 2007: 126 lizards, with an uncertainty range of 62 to 254, and 58.33 percent of the animals caught were unmarked, meaning they had already hatched on the islet. We have not found a more recent one.
Large droppings have been seen at Agache and Arelmo, but according to the plan there is no information at all on the state of these two possible populations. According to the scientific paper, a survey was scheduled at Agache for 2026, which had not been possible earlier for lack of funding and resources. At the time of writing, we had not found any published result. At Punta de Miguel, no trace of the lizards could be detected by 2018.
The number in captivity is not clear either. The plan mentions 312 at the end of 2021, based on ATAN's 2021 data, and 185 based on the 2022 work by Bohórquez and Molina; the 2026 scientific paper gives 216; and in May 2026 the Canary Islands Government spoke of more than 60 adults and 93 hatchlings. We don't add these up, and we don't read a trend into them.
The plan also admits that the genetic diversity and structure of the wild and reintroduced populations are unknown.
Cats, according to two sources
According to the plan, cats are the greatest threat, and the archipelago's best giant lizard populations live where cats cannot reach. Because the giant lizard is large and matures late, it is more likely to fall prey to a feral cat before it breeds.
According to the 2026 scientific paper, campaigns on El Hierro trapped 472 cats between 2001 and 2024, including 139 on the Risco de Tibataje, 182 at La Dehesa and 143 at El Julan. The campaigns were halted in 2024 because of restrictions in Spain's animal welfare law.
The 2026 recovery plan calls for continuous, high-priority cat control in and around the lizard's habitats, using selective live-capture traps. What happens to the animals caught is decided case by case: adoption, relocation to a cat colony or, where unavoidable, euthanasia.
We don't know whether trapping has resumed since the plan was approved.
Why this matters today
The species' new recovery plan, Decreto 40/2026, sets a target of at least five stable populations in the wild, including the existing ones, and designates three critical areas: the Fuga de Gorreta, the stretch of coast at Arelmo and Agache, and the Roque Chico de Salmor. Its estimated cost is 1,991,187 euros, although the plan itself says this is only an indicative figure.
According to preliminary analyses by the authors of the scientific paper, not yet published, a release has a better chance of success if it starts with at least a hundred lizards.
According to the plan, most of the pressures remain, and some, such as the number of cats breeding unchecked on the island, have grown considerably. The greatest natural threat on the Fuga de Gorreta is the cliff itself: a rockfall could wipe out the only wild population.
In 1974 the fate of the species hung on a matchbox, a shepherd's memory and the decision of two officials. Today it has a recovery plan, a breeding centre and decades of data behind it, and yet its wild population still lives on the same cliff that only the goatherds knew about back then. The knowledge that led to the rediscovery did not come from a book, but from the people who were out on the cliff with their goats every day.
What is there around you that only someone who passes that way every day knows, and that nobody has ever written down?
Where to see the giant lizard
The giant lizard recovery centre is part of the Ecomuseo de Guinea, in the municipality of Frontera, in the El Golfo valley. The guided tour starts in a lava tube, continues at the recovery centre with several lizards, and ends in a village whose houses evoke different centuries. You'll find opening times and prices on the operator's website.
Nearby, on the coast at Las Puntas, stands the Hotel Puntagrande. The Mirador de la Peña and the Mirador de Jinama look down over the El Golfo valley. You can still visit the sites of the two failed reintroductions today: at La Dehesa stand the wind-twisted junipers of El Sabinar, and at El Julan the Mirador de El Julan and the Parque Cultural de El Julan are waiting for you. In Frontera, the municipal market is also worth noting down.
To go with the island's museums and the full El Hierro guide, we recommend: What to see in El Hierro and Beaches and natural pools in El Hierro.
Sources: Decreto 40/2026, de 17 de marzo, Plan de Recuperación del Lagarto Gigante de El Hierro (Boletín Oficial de Canarias, no. 56, 23 March 2026); M. Á. Rodríguez Domínguez and co-authors: El Lagarto Gigante de El Hierro (Gobierno de Canarias and Cabildo de El Hierro, 2000); M. A. Rodríguez-Domínguez and co-authors, Animals 16(12):1869 (2026); Atlas y Libro Rojo de los Anfibios y Reptiles de España (MITECO, 2002); Cabildo de El Hierro, news (2024, 2026); Gobierno de Canarias, news item on the new plan (2026); RTVC (2024); Turismo de Islas Canarias (elhierro.travel); E.I.S. Meridiano, Ecomuseo de Guinea.
Cover photo (cropped): El Hierro giant lizard (Gallotia simonyi) at the recovery centre, El Hierro. Jose Mesa, CC BY 2.0, via Wikimedia Commons.