Flora and Fauna of Ons Island
The flora on Ons island is mainly scrub: heath, blackthorn, ferns, broom, Retama broom (Cytisus insularis) and gorse. The trees that can be found are mainly willows and alders in the small watercourses, and to a lesser extent, eucalyptus, pine and Pyrenean oak trees. Ons is currently deforested, but in the past, it was covered with native species such as Pyrenean oak (Quercus pyrenaica), cork oak or the white crowberry (Corema album) in its sandy areas.
You will find it interesting to know that on both this island and Sálvora Island, there is an endemic “xesta” or Retama broom species called “xesta de Ons” (Cytisus insularis”). Its stems and branches are more upright and stiff and its leaves are unifoliate, with its fruits flattened and a greater number of seeds per fruit. It is classified by the IUCN (International Union for the Conservation of Nature) as “endangered” because it is only found on these two islands of the National Park. Despite the fact that this species is in a good state of conservation on Ons, it is less so on Sálvora, which is why it raises certain concern.
In terms of fauna on the island, the marine environment is best represented in the Park.
In rocky areas, you can find organisms such as goose barnacles, limpets, mussels, barnacles, etc. In the intertidal zone, there are sea urchins, anemones, winkles, crabs, gobies or octopuses. In sandy bottoms you can find: razor shells, cockles or clams, turbot, cuttlefish or hermit crabs. The abundance of marine organisms supports nesting populations of seabirds such as the yellow-legged gull and common shag, which have very important colonies worldwide, and to a lesser extent, the lesser black-backed gull and European storm-petrel. These resources are also used by wintering or migratory birds such as the great cormorant, Northern gannet, Balearic shearwater, razorbill and common guillemot. In areas with less marine influence, birds such as the peregrine falcon, amphibians such as the salamander, reptiles such as Bedriaga’s skink, or insects such as the hard-to-find harlequin butterfly can be found.
Discover this natural paradise
You can go on Starlight trails, hike, swim in its crystal-clear waters, enjoy some lovely octopus tapas, lose yourself in the sound of the sea…