The physical environment and climate of Gran Canaria, which for most of its existence have facilitated the development of a varied and exuberant plant cover, are key factors in enabling countless animals to find conditions that have allowed them to settle and survive in isolation.
The trade winds and the Atlantic exert a greater or lesser effect, conditioned by the rugged terrain, producing a host of micro-environments; this factor increases the chances of finding a suitable habitat and facilitates the phenomenon of adaptive radiation, through which the evolution of one species can give rise to many others.
La Aldea is currently the habitat of thousands of species of invertebrates, hundreds of fish, dozens of mammals, at least six reptiles and more than a hundred birds, which have arrived on their own and have established themselves sporadically or permanently, both on the surface and under the water.
The endemic birds are deserving of special interest; they prominently include the Canary Islands chiffchaff (endemic to the archipelago), the blue chaffinch (endemic to Gran Canaria) and the pelagic birds that nest in the ravines and on the cliffs: Cory’s shearwater, Bulwer’s petrel and the European storm petrel. Other noteworthy birds are the populations of Eurasian stone curlew, trumpeter finches and rock sparrows, which find one of their last refuges on the island in El Valle.
The degree of endemicity is particularly high within the group of invertebrates. The three endemic terrestrial reptiles — the Gran Canaria skink, Boettger’s wall gecko and the Gran Canaria giant lizard — appear well distributed over the municipality. There are two known species of bats, the European free-tailed bat and Savi’s pipistrelle, which are the only native terrestrial mammals. And the coastal strip is very important for many of the 30 species of cetaceans (whales, dolphins, porpoises) sighted in the Canary Islands, sea turtles and many invertebrates and fish, including some of the most endangered sharks on the planet.
In view of their importance to certain animals, special consideration must be given to the cliffs of Andén Verde and Guguy, the coastal strip bordering the municipality to the west and the expanses of seaweed present there, which constitute the last “great” refuges for seabirds to breed and feed and an important place for dolphins, whales and sea turtles. The beach of La Aldea is a sanctuary for the angel shark, and the wetland area of Las Marciegas is a wintering and migratory site for many waders, anatids (ducks, geese, swans), swallows, swifts and other small passerine birds.
In the interior, the pine forests are inhabited by numerous species and subspecies of endemic woodland birds, the Inagua massif is the main area of distribution for the blue chaffinch and the rocky ravines and precipices are crucial for birds of prey, most of which are also endemic subspecies. Herons, egrets and occasionally other rarities winter on the reservoirs of Barranco Grande.
Practically any spot is important for invertebrates. And the terrestrial molluscs are particularly prominent, with a very high percentage of endemic species. This is not to downplay the significance of the other groups that inhabit both land and water and represent the great bulk of the animal biodiversity.