The Navarran Pyrenees is characterised by a large natural variety and diversity, which offers beautiful and surprising landscapes. The mountain range gradually flattens from east to west: from the imposing escarpments of the Larra massif, through the large expanses of beech woodland in the Irati Forest, or the depth of the Arbaiun gorge to the rolling hills and green meadows of the Atlantic Pyrenees. To the far west, the karst landscapes of the Aralar mountain range and the Urbasa-Andia Natural Park mark the natural ending point of this mountain range.
Hence the flora and fauna found here is very diverse, and are particularly conditioned by altitude. In any case, the sharp relief causes the geographic proximity of ecosystems to be very different.
Depending on the altitude, there are 3 main zones.
1.- Lowlands: corresponds to the lowest area and is located on the two extremes of the Pyrenees. The southern part of the eastern area is Mediterranean in nature and is composed of holm oak varieties, dry pastures and other shrubs. The far west is Atlantic in nature, with oak forests and mixed deciduous woods.
2.- Middle mountain: is the area that covers between 500 to 1700 metres. It is divided into two levels: lower or sub-mountain, of sub-Mediterranean type, covered with oaks, gall oaks, boxwood and blue aphyllanthes; and the higher or mountainous part, with deciduous woods (beech, firs) and common pine.
The forests in both levels have a rich and varied fauna:
On the one hand birds such as blackbirds, thrushes, great tits, blue tits, robins, hedge sparrows, finches and the noisy jays, and on the other hand, nocturnal birds of prey such as the long-eared owl and the tawny owl, or day-light hunters such as the buzzard, the bald eagle and the red kite.
We can also find a large amount of wild boar, deer, roe deer, foxes, squirrels, martens, common genets, rabbits and hares, among other mammals. And beneath the trees there is another beautiful inhabitant: the wildcat. Regarding the largest of all the mammals, the brown bear, specimens can only be seen very sporadically.
There are also numerous rodent species in the woods, such as the Pyrenean muskrat and the eye-catching grey dormouse and the garden dormouse, and another mammal that is perfectly adapted to the aquatic environment, the otter. Among the bird species linked closely to rivers and streams are the evasive kingfisher and the dipper.
The grass frog and the Pyrenean frog thrive in mountain lakes and cold-water streams, a space they also share with another flourishing Pyrenean species, the Pyrenean mountain newt. Of course, the common trout is present in the majority of the rivers in this area, as can the rainbow trout, which can only be found in high-mountain waters.
Among the most representative reptiles are the European asp, the most dangerous of all European vipers. The large diversity of climates and vegetation means there is an extraordinary variety of butterflies.