Nature Park of Alvão the moist lands along the riverfront. The Olo River is rich in trout and is populated by the Eurasian otter ("Lutra lutra"). Throughout the region, bird populations are diverse and include nesting pairs of Golden eagles. Mammal populations are marked by the presence of Wild boar ("Sus scrofa"), Roe deer ("Capreolus capreolus"), European badger ("Meles meles"), Granada hare ("Lepus granatensis") and European rabbit ("Oryctolagus cuniculus"). Among reptiles in the area are the Iberian emerald lizard ("Lacerta schreiberi") and the Latastei viper ("Vipera latastei"). No less important to the region is the traditional architecture of the nature park region, especially in
Meles (genus) has been much discussion as to whether it is a single species or three distinct species. There are geographical differences between individuals from different parts of the range in skull structure, morphology of the first premolar teeth, and facial markings. Some authorities advocated placing European and Asian badgers in separate species, "Meles meles" and "Meles leptorhynchus" (Milne-Edwards, 1867), the boundary between the two being the Volga River. Others considered there to be three subspecies, "M. m. meles", found west of the Volga, "M. m. arenarius-leptorhynchus", found between the Volga and Transbaikalia, and "M. m. amurensis-anakuma" from the Amur region and