The Azores archipelago, a collection of nine volcanic islands in the middle of the North Atlantic Ocean, is known for its dramatic landscapes and mild maritime climate. This Portuguese territory is positioned approximately 1,500 kilometers from the European mainland, creating a unique biological environment. The islands are overwhelmingly snake-free, a fact deeply rooted in their remote location and geological history.
The Definitive Status of Snakes
The Azores are officially considered to be free of any known native or established wild snake population. This definitive absence means that no species of snake has successfully colonized, reproduced, and maintained a viable population across the archipelago over time. This fact distinguishes the Azores from many other landmasses.
While the established status is zero, occasional, isolated sightings of individual snakes have been reported over the decades. These instances are almost always traced back to stowaways arriving unintentionally via cargo ships or, in rare cases, escaped or deliberately released exotic pets. Such sporadic arrivals do not constitute an established population, as the animals fail to find a mate or suitable conditions for long-term survival and reproduction.
Factors Contributing to Snake Absence
The primary reason snakes have not established themselves is the extreme geographic isolation of the archipelago. The islands formed from volcanic activity on the Mid-Atlantic Ridge and were never physically connected to any continental landmass. All terrestrial life that reached the Azores had to cross vast stretches of open ocean.
Snakes are generally poor oceanic dispersers compared to organisms like birds or insects. Successful colonization of a remote island typically requires a rare event called “rafting,” where a creature is washed out to sea on vegetation or debris. For a terrestrial reptile to survive this long journey, find a mate upon arrival, and establish a breeding colony is an event with extremely low probability, especially across the immense distances separating the Azores from Europe or North America. The immense barrier of the Atlantic Ocean has effectively filtered out these types of terrestrial reptiles.
The Native Reptile and Amphibian Population
While snakes are absent, the islands are home to a modest herpetofauna consisting entirely of introduced species. The most commonly seen reptile is the Madeiran wall lizard (Teira dugesii), which was accidentally introduced via shipping trade. This small, non-venomous lizard is the only land reptile to have successfully naturalized across all nine main islands.
The amphibian population consists of a few introduced frog and newt species that have found suitable habitat in the islands’ numerous lakes and wet areas. Examples include the Iberian green frog (Pelophylax perezi), introduced in the 19th century, and the Italian crested newt (Triturus carnifex), which established itself on São Miguel Island. These small creatures are harmless to humans.