Population
Monitoring
The red squirrel is one of the most threatened of native UK mammals and one of the important recommendations of the red squirrel SAP is to carry out long-term monitoring to assess population trends in different areas and the effects of interaction with the grey squirrel. It is also important to monitor populations to assess the effects of conservation management on local populations.
There are six existing methods for monitoring red squirrels, but all the methods have problems and only two of the methods can differentiate between red and grey presence (Gurnell et al., 2004). Transect walks noting sightings of red squirrels, accompanied by distance sampling if appropriate, is problematic because of very low encounter rate in low density populations, giving sample sizes too small to allow statistical analysis. An indirect method, using hair-tubes to assess presence/absence could be adapted to assess abundance but only one study has tested this possibility (Garson & Lurz, 1998). There are additional problems associated with red squirrels not entering hair-tubes when greys are present (Cartmel, 2000), and the possibility of encouraging interaction between the two species and the spread of poxvirus, which is a fatal disease for red squirrels.
A review of all the methods and relevant studies has been carried out by Gurnell et al. (2004) and recommendations have been made for further work to develop monitoring methods for this species.
A consortium of organisations is carrying out a two-year scoping study to investigate all the potential options and develop a protocol for a comprehensive surveillance and monitoring scheme for red squirrels across the UK. The scheme should be able to detect population trends and distribution changes and should be able to differentiate between red and grey squirrels in areas where both occur or in the interface between populations of the two species. The scheme will also be able to monitor the rate of grey incursion into red squirrel areas. A report on the work is expected in 2007.
In Northern Ireland the Environment and Heritage Service recently commissioned a study into changes in red
squirrel distribution, following a previous study that estimated red squirrel population size in Northern Ireland
(O'Teangana,1999). The report (O'Teangana et al., 2000) showed that grey squirrels are continuing to expand and long
term red squirrel survival is now only likely in large conifer woodlands.
Legal status
As the red squirrel is still widespread and common throughout Europe, with the exception of northern Italy, it is not protected by the Habitats Directive and is listed as Lower - risk, not threatened in the IUCN red data lists. However, the red squirrel is vulnerable in the UK and is therefore fully protected under UK legislation. This provides protection for both the animals themselves and their dreys.
For more information on legislation for red squirrels see the advice note Red Squirrels and the Law.