The continued presence of humans in Parnon, combined with relatively easy access, has led to the gradual extinction of several species of fauna and especially of large mammals.
Generally, the endemic, endangered, rare and protected species of fauna are distributed as follows: 12 mammal species, 53 bird species, 2 fish species, 20 reptile species, 6 species of amphibians and 17 species of invertebrates.
The wild mammals living in Parnon are mainly nocturnal species, small and medium-sized. In mount Parnon exist the usual throughout Hellas species, such as hare, fox, badger, marten, mink, jackal, some rodents and bats. Of these species, rare and endangered can only be considered the jackal, whose populations are steadily decreasing in Hellas, while it does not appear in another EU country.
The wild mammals that are encountered in Parnon can not be compared either in number of species or populations in the mammals that once lived here. Considering that in the entire Peloponnese have been found, in earlier times, species that have been lost, it can be assumed with some certainty that in Parnon lived in the past these types of mammals:
Brown bear (Ursus arctos) – It disappeared after the 15th century.
Lynx lynx – It disappeared in the early 20th century.
Wolf (Canis lupus) – It disappeared around 1925.
Deer (Cervus elaphus) – It disappeared in the last period of the Ottoman Rule.
Roe (Capreolus capreolus) – It disappeared in the early 20th century. Some individuals were “re-entered” recently.
Bobcat (Felis sylvestris) – It is unknown when it disapperead exactly. Probably during the 20th century.
Unlike mammals, avifauna in Parnon is extremely rich. While Parnon has a large variety of birds, the wetland of Moustos is used as food and rest station for many rare migratory bird species.
The avifauna of Parnon includes 217 species, some of whom live permanently in the region, others come in summer or winter, and some appear passing the region.
Of these species, 53 are endangered and / or protected. The most rareappear in mount Parnon, and some in Moustos wetland.
Even though the tops of Parnon have a low bush vegetation, and little species diversity, they are of particular interest because of the existence of birds specially adapted to this environment.
The forest mountainous area of Parnon (about 800-1.500 m.), with the mildest climate and the rich forests of black pine and fir, maintains very dense populations of birds. It is interesting that these birds do not occur only at sites in mountainous area, but throughout the region, a relatively rare phenomenon in the mountains of the hellenic mainland.
The semi-mountainous and wooded brushy area (about 600-800 m altitude) also presents great ornithological interest, not only on the density of the populations of species but also in their diversity. In this area are built several of the villages of Parnon. The deciduous or mixed forests and small fruit or vegetable fields that surround them, offer a wide variety of habitats. In addition, the current existence of water near several of these villages has significantly improved living conditions and reproduction for tens of species of birds, so that (around such villages) there have created literally small «ornithological havens».
Finally, the semi-mountainous hill area with shrubs of evergreen and broadleaf plant species(from the coast up to about 700 m altitude) presents no special ornithological interest compared with other regions of Greece. And in this, however, the variety of species and density of the population is remarkable.
The wetland of Moustos, based on the presence of a large number of endangered species to a limited extent, is emerging as an area of utmost importance for avifauna throughout Parnon. Although relatively small, however, it includes a wide variety of habitats, like coastal lagoon, canals, reed beds, etc. and thus its great variety of species.
Moreover, Moustos is the largest and the only worthwhile size wetland in the eastern Peloponnese, and the first to encounter migratory birds that follow the eastern coast of Greece to the north. The next (big) wetland is that of Sperheios. The broader therefore importance for aquatic birds concerns the use of the wetland as a rest and food stop during migration. In addition, some endangered species maintain some nests.
The birds are a special group of animals, very important in the ecology of a region because:
These characteristics, combined with the relatively easy observation and recording, make them excellent environmental indicators. This means that, recording the birds that exist in a region, one can assess the ecological situation. The greater the diversity and density of avifauna in a region, the greater its ecological value.
Immigration is a seasonal movement, from areas where living conditions are difficult in areas with favorable conditions. From the world of bird species, nearly half spend their winters and summers in different areas, crossing long distances during spring and autumn.
How are they oriented? During the day, they often use the sun as a compass, and during the night they are driven by the stars. Every 24 hours the stars rotate around a fixed point. It is noteworthy that the birds have the ability to identify a specific point and to combine the position of the moon and the magnetic field of the earth. Also, very often, migratory birds set their course (during the day) using landmarks, as rivers or coastlines. In some areas, millions of birds use as a guide strechy capes before crossing the sea. It is also believed that young birds, driven by their parents, memorize large parts of the route, taking as reference points the most characteristic features of the areas from where they cross.