UK Biodiversity Action Plan mammals found at Ruperra include dormouse, greater horseshoe bats and lesser horseshoe bats. Protected species include the badger. Only the dormouse uses the reserve to breed, and the site is part of an important stronghold for this species in the Caerphilly area.

Reliant on semi-natural woodland, the restoration work on the hill will benefit all of these species and surveys will start soon.

In spring and summer, the hum of insects at work is carried far in the air. From the buzzing of the bumble bee in the early months of the year, to the summer flights of beautiful butterflies, the varied habitats of Ruperra provide a home for a terrific diversity of invertebrates.

In March, look out for the brimstone butterfly, with the common speckled wood making its show around April. On the grassy and bracken top, look out, or listen for grasshoppers.