There are 9 species of mice/vole and rat in RCT. Of the mice the wood mouse is abundant and particularly so in the mosaics of lowland woodlands, permanent grasslands, gardens and hedgerows that make up much of the Authority. Many people see wood mice in their gardens or entering houses/outbuildings in the autumn and such they are a familiar species. On the other hand, we have no positive records of yellow-necked mouse. However, this arboreal species is strongly associated with lowland semi-natural woodland sites and as such the well-wooded parts of the County Borough may prove to support populations of ‘yellow-necks’. We are similarly ‘in the dark’ with regards to the house mouse. Again, the assumption is that the house mouse occurs in RCT (it far from an entirely urban species) but we have no recent records. However, there is better luck with the harvest mouse. While placemats on dining tables have cute pictures of harvest mice ‘couples’ living in yellow wheat fields, they really prefer wetland sites and, in RCT, they are found in unmanaged marshy grasslands. Indeed, the Review of British Mammal quotes Perrow’s and Jowitt’s opinions that harvest mice ‘are often the most abundant small mammal in wetlands’. Tussocks of purple moor-grass are important and provide the material for the skillfully weaved, ball shaped nests. An effective way to find evidence of harvest mice is to look for old nests in the winter when they can be easier to see. So far, old harvest mice nests have been found in a several different fields within the Rhos Tonyrefail SSSI, Llantrisant Common SSSI and Llantwit Fardre (as part of searches for marsh fritillary butterfly larval webs): there seem little doubt that the harvest mouse will use similar habitat elsewhere.

The bank and field voles are both common species. The ‘bank’ is supposed to be more strongly associated with woodlands and hedgerows and the ‘field’ prefers ‘tussocky’ grasslands. Rough grassland sites, whether wet or dry, are usually full of vole runs, evidence of vole feeding (piles of neatly cut grass stem) and vole droppings. It can be assumed that the field vole populations of RCT are huge. Although not native, it is impossible not to mention the brown rat; abundant and beautifully adapted to modern life, brown rats rate the highest of high on any list of vermin.

Three species of shrew occur in RCT. Common shrews are abundant and much more frequently heard (shrews are shrill!) than seen alive (dead common shrews are often come across – they live frantic, but short lives). If our ‘shrew’ situation matches the national picture, the pigmy shrew will not only prove to be common but will be more abundant than their bigger cousin on our upland bogs and heaths. The water shrew lives a semi-aquatic life and is found in wetlands with pools and streams. Water shrews have been found on several wetland sites in RCT (sometimes discovered using reptile refuges) and together with harvest mice they are an important part of the small mammal fauna of such habitats.

Originally a woodland species, moles appear to be well established and distributed in RCT, particularly so in lowland areas. The ‘Review of British Mammals’ highlights the importance of soil depth for moles (enough depth is needed to tunnel), so can it be assumed that the thinner valley side soils of our valleys support fewer moles?

The two commonest mustelids are the weasel and stoat. These are assumed to be common and widespread species, but we receive very few reports or records of either species.

Of the ‘rarer’ species, polecats are quite frequently killed on our roads: indeed, polecat is probably one of our better-reported mammal species. Photos of a number of these have been sent to the Vincent Wildlife Trust for verification and those were confirmed to be pure-bred polecats, rather than some ferret or polecat/ferret cross. Occasionally, there are reports of live polecat from farmyards or allotments and young animals have been caught in (and released from) ‘live-catch’ rat traps. The evidence strongly suggests that polecats are well established in RCT and may be common.

In the early 2000s, the Vincent Wildlife Trust co-ordinated a pine martin survey of Wales. This primarily consisted of collating records submitted through a well-publicised poster campaign. The interim survey findings included two (high confidence) records from the Brecon Beacons National Park bit of RCT, just north of Hirwaun. Tantalising, in the early 2000s we received several unconfirmed, but plausible pine martin reports, but nothing since. With the re-introduction of pine martin to Mid Wales, and the connectivity of suitable habitat that reaches into RCT, pine martin may be reported in RCT.

The Badger is a secretive species in RCT. They are present and may be well distributed, but the lack of roadkill and other reports does suggest that they are uncommon. Persecution and disturbance may be a factor in the species scarcity, but the thin valley soils of much of the RCT may hamper sett digging, and in general RCT may just not be a prime badger habitat.