Red squirrel conservation in Clocaenog forest

 

The grey squirrel, sciurus carolinensis, became common throughout Wales by the early 1960s having gradually displaced the red squirrel, sciurus vulgaris, from much of its former range.
The red squirrel is now confined to a few conifer plantations in north and south Wales. Clocaenog Forest in North Wales is believed to have the largest population of red squirrels in Wales and is probably their last stronghold. However, this 5,000 ha conifer plantation also has a small (<100) resident population of grey squirrels. Because of the concern over the decline of the red squirrel throughout the UK, a project was set up in November 1992 in an attempt to determine the status of the red squirrel population in Clocaenog Forest and the influence that the grey squirrels were having on this population.

One theory, concerning whether greys will replace red squirrels, is that red squirrels may be better adapted than grey squirrels to living in large conifer forests - especially if few or no broadleaf trees are present. If this were supported by the research in Clocaenog, then it would have an important bearing on the management of forests for red squirrel conservation.

The project consisted mostly of live trapping and radio tracking squirrels over a six year period. This gave an indication of the density of squirrels present in certain areas and the habitat preferences of the two species. Both species of squirrel are very much dependent on conifer cone seed in coniferous forests and so cone transects and canopy photographs were used to determine food availability within the forest and this information was also used to complement the habitat preference data from radio tracking. Two sites were selected for detailed studies that differed in tree species composition  (especially in the presence of broadleaves), location within the forest and initial presence of grey squirrels.

The red squirrel population size was found to fluctuate with conifer seed availability but generally remained relatively stable over the study period. The density of red squirrels was low, averaging about one squirrel every three to four hectares, similar to that found in several studies in other conifer forests.

Grey squirrels were resident in part of the forest containing broadleaves but were found to be transient in areas of pure conifer (Sitka and Norway spruce), only being present in years of high food availability. This backs up the theory that red squirrels are capable of surviving better in conifer forests (assuming the right tree species are present to provide a food source). The presence of grey squirrels did not directly affect the red squirrels, but it appears that the breeding success and survival of juvenile red squirrels over their first winter declined in areas where grey squirrels were also breeding.

Both species were found to have similar food preferences, favouring conifer seeds of Scots pine and Norway spruce, and Japanese larch when available. Neither species favoured Sitka spruce although grey squirrels appear to utilise this species more than red squirrels. Beech was the predominant broadleaved species found in Clocaenog but it was only present in a few small areas. Beech produced a mast crop once during the study and the grey squirrels were found to significantly use this food type. Red squirrels were also observed feeding in beech but not to the same extent as the grey squirrels.

Red squirrels were found to adapt to forestry work such as thinning by shifting their home ranges to adjacent suitable areas. They returned to their original home range area once the work was complete, providing the area was still suitable for the squirrels (e.g. not over-thinned).

The future of red squirrels in Clocaenog Forest is still very much in the balance. It is a commercial forest and timber crops have to be managed as such. A series of management guidelines were produced from the results of this project that have been implemented by the Forestry Commission.
Research on the red squirrel population is continuing, the area to the west of Llyn Brenig is being surveyed to determine the extent of the red squirrel population and to compare this population genetically with that in the main forest block. There is also constant surveillance of the grey squirrel population to ensure that it does not increase to the detriment of the red squirrel.
Hopefully with the right management techniques the red squirrel is here to stay in Clocaenog Forest.

Dr Sarah Cartmel

The following publications are available to view on-line;
Red Squirrel Conservation
Practice Note 005 - Sep 1998
Practical Techniques for Surveying and Monitoring Squirrels  
Practice Note 011 - Sep 2001