We refer here to woods made up of broad-leaved oaks: Pedunculate oak (Quercus robur), Sessile oak (Quercus petraea) and Pyrenean oak (Quercus pyrenaica).
These mainly spread over the so-called Humid Navarre of the north, north-east and the heads of the Pyrenean valleys. Pedunculate-oak woods occupy the bottoms and low slopes of the region?s Atlantic valleys and valleys in the mountainous areas of the north-west. The other types of oak appear at mid-slope level; the Pyrenean oak, in contrast to what one might imagine, avoids the Pyrenean area, where the Sessile oak flourishes.
Over history, these woods have been used by the traditional timber trade in a fairly balanced manner, though their very accessibility has led to large ruptures, the oak woods now remaining being but a mere shadow of their former selves.
In general, these are fairly open, heterogeneous woods with a wide range and good coverage of underwood, favouring the existence of varied layers of vegetation and thereby creating numerous niches of interest. As they mature and age, oak trees develop numerous hollows and holes which provide excellent refuges for birds and other organisms.Birds:
The great heterogeneity of the landscape and structure of these woods favours varied, fairly high-density bird communities of between 80 and 120 birds/10 Ha. The abundance of hollows in the oak trees means that a great proportion of the species present are birds which nest in holes and cracks.
The characteristic birds to be found in these woods include the Great Spotted Woodpecker, Wren, Robin, Blackbird, Song Thrush, Blackcap, Short-toed Treecreeper, European Nuthatch, Blue Tit, Great Tit, Marsh Tit, Common Chaffinch. Less common, but also habitual are the Common Cuckoo, Iberian Green Woodpecker, Lesser Spotted Woodpecker, Firecrest, Spotted Flycatcher, Iberian Chiffchaff, Bonelli?s Warbler, Mistle Thrush, Long-tailed Tit, Common Starling and Common Bullfinch.
Birds of prey are represented by the European Honey-buzzard, Black Kite, Red Kite, Eurasian Sparrowhawk, Northern Goshawk, Common Buzzard, Booted Eagle, Short-toed Eagle and Hobby. Nocturnal birds by the Barn Owl, Tawny Owl and Long-eared Owl.
Rarer are the Woodcock, Common Woodpigeon, Golden Oriole, European Nightjar, Middle Spotted Woodpecker, Wryneck, Pied Flycatcher, Common Redstart and Garden Warbler.