Lots of local invertebrate species from the territory of NySzTT are discovered and described by scholars that characterise the Western mountains.
There are three groups:
The most specific species are the Drimeotus and the Pholeuon troglobionts in the Western mountains, because of their limited spread. There are almost fifteen Drimoteus (Bihorites) races and subspecies' live in this territory. Between these races the Drimotheus (Fericeus) and the Drimoteus (Trichoparis) constitute a specific subspecies. Another local subspecies the Pholeuon (s.str.) among the Pholeuons. There are almost 22 representatives of this race in this territory.
There are 18 (Duvalius) species and subspecies in the Bihar mountains despite of the race of Duvalius is non-specific in Romania, so this is an important scientific achievement. These beings are live under the ground in caves all over the park’s territory. Their freqency is really limited, because of their living coditions: it is a very vulnerable race and a slightly change (for example cave visiting) can modify their lifestyles. (Oana Moldovan, ISER Cluj-Napoca, 2006)
The Valley of Aranyos and the most of its affluents are rich in fish and that's the reason why it is so popular.
Rich in fish shows different picture in every period of the river:
The Salmo irideus and the Salvenilus fontinalis is naturalized by humans in this territory.
In this area there are almost every kind of mountain birds.
In conifer forests:
In deciduous forests, on glades and ranges:
Near by rivers:
Raptorial birds protected by national and international laws:
The world of the forests consist of deciduous and coniferous wood's ordinary animals (besides ibex, that is setting at the upward period of Boga and Köves-Körös, but nowdays found in Rozsda-hole, and near by Csodavár and Scăriţa.).
There was a re-settling movement in 1970s and 1980s, when capercaillie was re-settling. The reason was the poaching completely exterminate the whole livestock.
According to local specialist of forestry and the Research Institute of Brasov indicate that approximately 26 wolfs live inside the territory of NySzTT. This data shows harmony: the characteristics of this race and the situation of living places are in connection. Wolfs live in flocks: 2 flocks (with 10, and 5 wolfs) in Kolozs county, 1-1 flock (with 6 and 5 wolfs) in Bihar and Fehér county were registered in 2005.
Another favourable thing is the number of lynx in the park: there are 20 lynxes (8 in Kolozs county, 4 in Bihar county and 8 in Fehér county).
Unfortunately bear’s situation is really bad: the ecosystem could be fit out more bears, but only 21 registered according to surveys: there are 7 bears in Bihar county, 12 bears in Kolozs county and 2 bears in Fehér county. This bear population isolated from the other groups living in Carpathians, so the genetic change can’t materialize. This missing genetic base could be dangerous, maybe this race will die out despite of provisions.
The otter protects by national and international laws. This species live near by rivers, isolated from human beings. Some flocks were settling next to upward period of Meleg-Szamos, Gârda Seacă and Bélis.
There are 10 races of murines; some of them expressly important.
Insectivorous mammals are really prevalent: 8 races are registered in this territory (without bats).