WildCRU’s Scottish Wildcat project began in the 1990’s following observations that hybridization with domestic cats was affecting legal protection of the wildcat. We studied ecological, evolutionary, morphological, reproductive and genetic differences of wild-living cats. Using our data combined with spatial modelling we have generated habitat maps to help guide conservation actions. We aim to positively contribute to conservation actions of the wildcat in Scotland by collaborating with organizations carrying out conservation work and using existing and emerging techniques to further our knowledge on the wildcat.
CONSERVATION CONTEXT
The European wildcat is the last remaining native felid in the UK, becoming restricted to northern Scotland in the early 1900’s after intensive hunting, persecution and habitat loss across the UK. Dwindling numbers of wildcats crossbred with unneutered introduced domestic cats which, descended from African wildcats, are genetically distinct to the European wildcat but closely related enough to produce fertile hybrid offspring. Consequently, the Scottish wild-living cat population comprises a “hybrid swarm” where individuals have a mixture of domestic and wildcat genes and morphologies but only wildcats are legally protected making protection and monitoring of the wildcat complicated.
The population in Scotland was classified as Critically Endangered in 2022. Our early research focused on whether any morphological, genetic or ecological differences existed between wildcats, hybrids and domestics. In 2004, we published the first Action Plan for conservation of the wildcat and directly contributed to the development of a pelage and genetics identification tool for monitoring the species. We pioneered the use of camera trapping as a survey method and carried out the first large scale camera trap survey across Northern Scotland generating new population density estimates and highlighting the widespread risk of hybridization. We have obtained detailed ecological data using VHF and GPS radio tracking contributing to our general knowledge of wildcats and hybrids. In addition to trialling field-based techniques, we utilised novel landscape modelling techniques to produce habitat suitability maps for the wildcat. Research outputs from the Wildcat Project have directly contributed to national conservation actions for the species.
APPROACH
Identification tools
Between 1993-1997 we assessed a range of morphological criteria of 333 wild-living cats across Scotland and identified Group 1 cats (with wildcat type pelage, longer limbs, larger skull size and shorter intestines) and Group II cats (with a range of non-wildcat type pelage, shorter limbs and longer intestines) which were genetically closer to domestic cats.
In collaboration with Dr. Andrew Kitchener (National Museums Scotland), we developed a pelage identification tool to identify wildcats from hybrids and domestic cats based on 7 specific coat (pelage) patterns (Kitchener et al., 2005). This is currently the primary method for identifying wildcats in the field in Scotland.
We carried out a genetic and phylogeny assessment of 629 wild-living cats, resulting in the development of a mitochondrial DNA (mtDNA) test that identified significant differences between domestic cats and European wildcats (Driscoll 2011; Driscoll et al., 2011). This mtDNA test is part of a suite of genetic tests currently used by researchers to manage both captive and wild-living populations in Scotland (see Senn et al., 2019)
Wildcat and Wildcat Hybrid ecology
In 1997 we radio tracked 31 wild-living cats to examine ecological and reproductive differences between Group I cats (wildcat type pelage) and Group II cats (non-wildcat type pelage) within the same habitats (Daniels, 1997). In general, we found no significant differences in home range sizes, habitat use and activity patterns suggesting wildcats couldn’t be differentiated from other wild-living cats based on ecological behaviour. The reproductive status of 185 carcasses and the 31 individuals radio tracked showed a peak of reproduction occurring in spring/summer with Group I females showing more seasonality in oestrous.
Between 2010-2015 we carried out wide scale camera trap surveys across parts of northern Scotland to examine current distribution and habitat use of wild-living cat populations, generating new population density and home range size estimates (Kilshaw 2015) and highlighting the importance of landscape heterogeneity and prey availability (da Silva et al., 2013). We found wildcats were at risk of hybridization across much of their current distribution from feral cats and/or hybrids with hybrids more likely to occupy much of the same habitat as wildcats than feral cats. Scat surveys found that wild-living cats were eating predominantly rabbit and vole species (Hobson, 2012), supporting other studies.
Between 2013-2014, funded by the Peoples Trust for Endangered Species, we trialled GPS tracking collars on wild-living cats to examine their behavioural ecology (Campbell 2015), expanding our previous work and providing the first detailed look at landscape use. We found cats with wildcat pelage showed a preference for broadleaved woodland and habitat ‘edges’ indicating habitat mosaics are important.
Between 2018 – 2023, as a partner in the government led Scottish Wildcat Action Conservation Plan, we used GPS collars to monitor wildcat hybrids in 4 of the 6 Wildcat Priority Areas. Appearing to fulfil the wildcat niche, we provided new information on rest site use, home range size and habitat use, demonstrated the importance of windthrow and gorse for rest sites, use of linear features to cross the landscape and larger than previously reported home range sizes (Kilshaw et al., 2023). In addition, risks potentially affecting wildcats were identified (e.g. use of farm buildings emphasised the importance of neutering feral farm cats, difficulties identifying dens and rest sites in relation to current legislation).
Since 2023 we have been assisting with the GPS tracking and data analysis of released captive-bred wildcats. This project is run by Saving Wildcats (www.savingwildcats.org.uk) and is the first translocation of captive bred wildcats into the wild in Scotland.
Monitoring methods
We carried out the first camera trap survey in Scotland for the wildcat and showed that the method could successfully detect wildcats and other wild-living cats and that individuals could be identified by their pelage allowing for population density estimates. We showed that baiting the camera traps also improved detection rates (Kilshaw et al., 2010). Camera trapping is now the main method used by practitioners across Scotland to survey for and monitor the wildcat.
We also showed that carrying out surveys with camera traps prior to live trapping (used for practical conservation such as trap-neuter-release, health screening and GPS collaring) greatly reduced overall trapping effort and that using remote cameras to send MMS images over the GSM/GPRS telecommunications network could be used to monitor cage traps remotely (where network coverage allows). This allowed researchers to respond quickly to individuals trapped and reduced overall disturbance to the trap (Campbell & Griffiths, 2015). This method is now widely used to improve trapping success rates for wild-living cats.
Landscape Ecology
Using the GPS data from wildcat hybrids we developed a habitat suitability map for wildcats which was validated with three independent datasets including the camera trap data, we are currently in the process of validating this with data from released captive bred wildcats. The next stage is to generate landscape connectivity maps to help focus conservation actions.
IMPACT HIGHLIGHTS
Our large-scale survey, deploying 930 camera traps across 23 different sites in Northern Scotland for a combined survey effort of 38,753 trap nights, captured 44 wildcats, 62 hybrids and 96 domestic cats on camera. We found that feral domestic cats and hybrids are widespread throughout the wildcat’s potential range in Northern Scotland and that hybrids in particular presented a significant risk to wildcats through occupying much of the same habitats. We generated new population density estimates (~160-300 wildcats) and suggested its current status of Least Concern at the time should be reviewed.
Camera trap survey data was used to help select the six Wildcat Priority Areas which were the focus of conservation actions undertaken by the government led Scottish Wildcat Conservation Action Plan (SWCAP) between 2013 -2019 and in the assessment of the current status of the species by the IUCN.
Our GPS tracking of 33 hybrids (ranging from 23% to 74% wildcat) and 7 domestic cats provided the first detailed look at habitat use by wild-living cats and expanding on our earlier work highlighting the importance of certain features in the landscape. We demonstrated how the difficulties in identifying rest sites (protected by law) is negatively affecting the abilities of land managers to effectively survey for (and therefore protect) the species. The GPS data has also been used to generate an updated map of potential habitat suitability for wildcats across Scotland.
Our early research morphologically assessing 333 wild-living cats and radio tracking 31 wild-living cats highlighted the complexity and difficulties of using conventional taxonomy or ecological behaviour as a means for distinguishing a wildcat and led to the first Scottish Wildcat Conservation Action Plan in 2004 and the pelage assessment tool in 2005. Genetic assessments of 629 wild-living cats led to the development of the mtDNA test in 2007.
PROJECT MEMBERS
WildCRU’s David Macdonald founded the programme; Dr. Kerry Kilshaw currently coordinates the programme and carries out the field work and data analysis, Dr. Sam Cushman and Dr. Zaneta Kaszta lead the spatial modelling.
Post-doctoral alumni; Dr. Nobby Yamaguchi and Dr. Roo Campbell. PhD alumni; Dr. Mike Daniels and Dr. Carlos Driscoll. Co-supervised MSc Alumni; Dr. Andre Silva, Dr. Keziah Hobson, Katheryn Cockle, Jenna Griffith, Victoria Standing, Katarzyna Ruta.