TNVR: Protecting Scottish wildcats from interbreeding with feral cats

The Saving Wildcats partnership is carrying out crucial work to restore Scottish wildcat populations at a landscape-scale.

An essential part of this project involves the protection of Scottish wildcats from interbreeding with feral cats, which the Saving Wildcats team carries out through a humane and non-lethal program called Trap-Neuter-Vaccinate-Return (TNVR). In this article, Lara Semple (In-situ Project Officer at Saving Wildcats) explains why an effective TNVR programme is essential for the project, describes the TNVR process, highlights the critical role of trail cameras for this work, and shares some of the unique challenges the team faces, such as the complexities of running TNVR in urban environments.

The Saving Wildcats partnership is dedicated to Scottish wildcat conservation and recovery, aiming to prevent the extinction of wildcats in Scotland by breeding and releasing them into the wild, while also mitigating the threats that they face. Wildcats are now on the brink of extinction in Scotland following widespread population declines after centuries of persecution and habitat loss. More recently, the dwindling wildcat population has become increasingly threatened by genetic extinction caused by interbreeding (also known as hybridisation) with domestic feral cats. Interbreeding produces ‘hybrid’ cats that have both wildcat and domestic cat DNA. To address this threat, Saving Wildcats has begun a programme of Trap-Neuter-Vaccinate-Return (TNVR).

Lara holds two traps used for the Saving Wildcats TNVR programme 

What is TNVR and why is it important?

TNVR is a humane and non-lethal method for controlling the expansion of feral cat populations. The TNVR work the Saving Wildcats team carry out is important to reduce the risk of hybridisation and disease transmission from feral cats with Scotland’s wildcats.

A small, healthy population of neutered and vaccinated feral cats may help to protect wildcats from hybridisation by maintaining a territory and keeping unneutered feral cats out of it.

Could you describe the TNVR process?

Saving Wildcats identify targets for TNVR work through extensive on-the-ground outreach with local communities, followed by door-knocking and leafletting to try and establish whether a cat is owned or not.

Once the Project Officers are satisfied that the ‘target’ cat is not owned and likely to be un-neutered, a humane and cat-specific trap is deployed with permission from the landowner. Food or valerian root (which is a scent cats love) is put into the traps to encourage them to come in. The Saving Wildcats team have a specific licence from NatureScot that allows us to carry out TNVR of feral cats. This licence is a requirement for releasing feral cats (a non-native species) in Scotland.

After a short period of pre-baiting, the traps are set overnight and checked early in the morning. If the target cat has no signs of ownership or previous neutering on inspection, it is quickly and carefully transported to our dedicated veterinary facility at the Royal Zoological Society of Scotland’s Highland Wildlife Park.

The vets will check the cat again for any signs of ownership. If they are happy to proceed, they will quickly inject the cat through the carrier to sedate it. This means that we don’t need to handle the cat while it’s still awake. The vets will perform a full examination of the cat and treat any minor conditions or mild injuries that may be helped with a single treatment. The cat will be neutered, vaccinated and given a spot-on parasite treatment.

After neutering a small piece (1cm) of the left ear tip is removed as this is the internationally recognised identification of a neutered cat. This heals quickly and ensures a feral cat is not trapped for TNVR multiple times.

After the neutering surgery, the cat will be placed in a warm and quiet recovery room. The vets will monitor the cat and, once happy it is recovering well, they will let the project officers know when it can be returned to its outdoor home.

Scottish wildcat x feral cat hybrid with tip removed from left ear for identification

Would you TNVR a wildcat-hybrid cat?

Wildcats can be distinguished from feral domestic cats based on their markings and appearance. Saving Wildcats project staff are trained in identification of potential wildcats based on a visual assessment using an established method called ‘Pelage Scoring’ including a distinctive bushy tail with black rings and a blunt tip.

Hybrid cats are treated in the same way as domestic cats and neutered, vaccinated and returned to where they were caught. This ensures that the wildcat genetic pool is not diluted with domestic cat genes, improves the welfare of hybrid cats and prevents further unwanted hybrid kittens.

Do you use wildlife trail cameras for TNVR work?

Yes, trail cameras are vital to our TNVR work. After a feral cat is reported to us by a member of the public, we place a trail camera on site to capture images of the individual. This helps us decide whether TNVR is necessary, as if we see a removed ear tip or a collar we do not need to proceed further.

During the pre-baiting and live trapping phase, we monitor all the locations using trail-cameras and GPRS cameras to confirm the trap has been triggered, to identify all the cats visiting the location, and to make sure no other species are trapped accidentally.

A Scottish wildcat x feral cat hybrid enters a TNVR trap

What kind of challenges do the team face with running the TNVR programme?

Unfortunately, TNVR is becoming more complicated with the number of unowned cats thought to be increasing. The sharp rise in demand for cats and kittens during the Covid pandemic, coupled with the lack of veterinary resourcing for neutering, led to the number of abandoned pets rising by 24% in 2022. On top of this, the cost-of-living crisis is currently seen as the most urgent threat to pet welfare in the UK according to RSPCA and SSPCA.

TNVR becomes much more complicated within an urban setting compared to a rural farm environment. This is mainly because there are generally more domestic cats and more likelihood of finding pet cats. Saving Wildcats work extensively with the local community to locate any pet cats surrounding the initial report of a feral or stray cat. We actively work to avoid trapping pet cats by alerting owners of the nights we’ll be trapping. We recommend that owners place a collar on and microchip their pet or keep their pet indoors during specific nights of trapping.

Another challenge is “trap happy” and “trap shy” cats. It is always the “trap happy” cats that you trap multiple times, which can mean there are fewer chances of trapping “trap shy” cats within the same location. ‘Trap happy’ cats quite like the free snacks they can find in our traps…To mitigate this, we always place multiple traps at each location, use different types of bait to attract different cats and practice a lot of patience!

Identifying different individual cats can also be challenging. We collect trail camera footage daily to identify cats visiting the site while pre-baiting. We add all new cats to our ‘Cat-a-logue’ so we can identify them in the future, which can be difficult with many cats at one location with similar markings.

Thank you to Lara and the team at Saving Wildcats for sharing these fascinating insights into the importance of TNVR for Scottish wildcat conservation.

Learn more about Saving Wildcats on our Project Pages.