El Hierro giant lizard
Critically Endangered (CR B1ab(v)+2ab(v))·Oviparous
The El Hierro giant lizard (Gallotia simonyi machadoi) is a critically endangered subspecies endemic to El Hierro, one of the Canary Islands. Historically much larger, modern individuals are smaller than their extinct nominate subspecies but can grow larger in captivity. This omnivorous lizard inhabits xeric scrubland on steep cliffs, relying on these protected areas for survival.
Key Facts
- ›Critically endangered subspecies of Simony's giant lizard.
- ›Endemic to El Hierro, the westernmost Canary Island.
- ›Omnivorous diet consisting of plants, insects, and small vertebrates.
- ›Reproduction involves laying clutches of 5-13 eggs.
- ›Primary defense mechanism is to run away, though less agile than other Gallotia species.
- ›Faces significant threats from introduced predators like feral cats and rats.
Simony's Giant Lizard, El Hierro Giant Lizard
El Hierro, Canary Islands
Xeric Scrubland, Steep Cliffs
- Smaller and Less Robust Than the Extinct Nominate Subspecies.
- Top of the Head Is Less Triangular and More Oval.
- Head Is Less Depressed.
- Fewer Dorsal Scales On Average.
- More Temporal Scales.
- Fewer Femoral Pores.
- Fewer Scales On the Sixth Tail Ring.
- Tail Is Approximately 1.4 To 1.7 Times the Length of the Body.
- Plants
- Coleopterans
- Ants
- Small Vertebrates
- Dead Orthopterans Regurgitated By Seabird Chicks
- Diurnal, Active Most of the Day and Year-Round.
- Slight Decrease In Activity and Increased Hiding In Summer.
- Tolerate Lower Temperatures Than Other Gallotia Species.
- Not Territorial, Adults Tolerate the Presence of Others.
- Juveniles Display Hostility To Same-Aged Animals But Ignore Smaller Lizards.
- Defense Includes Running Away, Opening Mouth, and Making Noise .
Common Kestrels, Buzzards, Ravens, Feral Cats, Brown Rats, Herding Dogs
- Predation By Introduced Feral Cats and Brown Rats
- Habitat Loss and Fragmentation
- Competition From Introduced Herbivores
About El Hierro giant lizard
The El Hierro giant lizard (Gallotia simonyi machadoi) is a critically endangered subspecies of Simony's giant lizard, found exclusively on the island of El Hierro in the Canary Islands. This species is an official symbol of the island and represents a significant conservation challenge.
Physical Characteristics and History
Modern El Hierro giant lizards are smaller than their extinct nominate subspecies, with adult males measuring between 120-200 mm and females between 110-160 mm in snout-to-vent length. Subfossil evidence indicates that these lizards were considerably larger before human settlement, with some individuals estimated to have surpassed one meter in total length. The subspecies differs from the nominate form in subtle morphological traits, including head shape and scale counts. Historically, the species was widespread on El Hierro, but human colonization brought about a significant decline due to hunting, habitat alteration, and the introduction of invasive predators.
Distribution and Habitat
Currently, the El Hierro giant lizard is restricted to a small, protected area on the Tibataje crag, a steep cliff face offering refuge from invasive mammals. A second population has been successfully established on Roque Chico de Salmor, a small islet northwest of El Hierro. These habitats are characterized by xeric scrubland dominated by various succulent plants and shrubs.
Diet and Behavior
The El Hierro giant lizard is omnivorous, feeding on a variety of plants, insects, and small vertebrates. They are known to distinguish and recognize the smell of their food sources. These lizards are diurnal, remaining active throughout most of the day and year, though they may seek refuge during the hottest summer months. They are not territorial and tend to tolerate the presence of other individuals.
Reproduction and Conservation
Reproduction occurs in late spring and early summer, with females laying clutches of five to thirteen eggs, which incubate for approximately 61 days. Efforts to conserve the El Hierro giant lizard began in earnest after its rediscovery in the 1970s. A successful captive breeding program has been instrumental in reintroducing individuals to protected areas. Despite these efforts, the species remains critically endangered, primarily due to predation by introduced feral cats and brown rats. Ongoing conservation strategies focus on habitat protection and rigorous control of invasive predators.
Source: Wikipedia ↗
Frequently Asked Questions
What is the scientific name of the El Hierro giant lizard?
The scientific name of the El Hierro giant lizard is Gallotia simonyi machadoi. It is a subspecies of Simony's giant lizard.
Where is the El Hierro giant lizard found?
The El Hierro giant lizard is endemic to El Hierro, the westernmost of the Canary Islands. Historically, it was widespread, but now it is restricted to specific cliff areas and a reintroduced population on Roque Chico de Salmor.
What does the El Hierro giant lizard eat?
The El Hierro giant lizard is omnivorous. Its diet includes a variety of plants, such as Liliaceae, Graminaceae, and various flowers and seeds, as well as invertebrates like coleopterans and ants, and occasionally small vertebrates.
What are the main threats to the El Hierro giant lizard?
The primary threats to the El Hierro giant lizard are introduced predators, particularly feral cats and brown rats, which prey on both adults and juveniles. Habitat changes due to human activity and competition from introduced herbivores have also played a role in its decline.
How large do El Hierro giant lizards get?
Wild adult males typically measure between 120 and 200 mm in length (excluding the tail), and females between 110 and 160 mm. Individuals raised in captivity can reach larger sizes, with males up to 226 mm and females up to 204 mm. Historically, before human colonization, they were much larger, potentially exceeding one meter in total length.
What is the conservation status of the El Hierro giant lizard?
The El Hierro giant lizard is classified as critically endangered by the IUCN. This status is due to its limited range, fragmented distribution, and ongoing threats, despite recent population increases.
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