Cats are amazing animals who have stolen the hearts of the nation. They are the second most popular pet in the UK, with an estimated 31% of UK households owning a cat. Cats may be popular with people, but several reports suggest they are causing harm to British wildlife – are they really that bad for wildlife?
The short answer is yes: some cats can have a significant negative impact on wildlife populations around the world, including the UK, and we will spend the rest of this article exploring why that is, and what we can do to change that.
Some cats? What do we mean by that?
Not all cats cause direct harm to wildlife. Whether a cat is an issue for wildlife depends mostly on whether they come into contact with wildlife, directly or indirectly. Indoor cats, or cats using an enclosed outdoor space such as a ‘catio’ pose very little harm to wildlife, as they are generally not able to access wildlife easily and their faeces are contained in a space that wildlife can’t easily access. As a general rule, cats that do not have direct access to the outside and cannot roam freely without supervision are much less likely to cause harm to wildlife.
How do cats cause harm to wildlife?
There are two main ways that cats can be harmful to wildlife:
1) through causing injury to wild animals by catching them and biting, scratching or killing them
2) through spreading disease via their faeces, which wildlife then come into contact with indirectly when it’s left in the environment through contaminated water sources or vegetation, even if they haven’t been in contact with the cat
How do cats cause injury?
Cats are known for predating birds and other small mammals. It is a natural instinct for cats to hunt and stalk small mammals and wild birds – if they didn’t have people to bring them food every day, this is how they would feed themselves as obligate carnivores. It is not something we can or should penalise cats for, but as their owners we do need to be aware that this behaviour can do significant harm to wildlife populations.
It is estimated that cats kill more than 200 million animals annually, including more than 40 million birds. Sadly, these numbers are just the tip of the iceberg, as it is not just the animals that are killed that are the issue – thousands of injured wild animals end up in wildlife rehabilitation centres every year due to cat attacks, with cat bite injuries being one of the most common reasons for a wild animal to be admitted to a wildlife rehabilitation centre.
The animals that are killed vary from newly fledged birds to adult birds trying to feed a nest of birds, where their death, or removal from the wild if they enter a rehabilitation centre, can result in a whole nest of baby birds going unfed and ultimately succumbing to starvation. The same is true for small mammal and rodent casualties.
In some populations, especially those where species numbers are low or declining, a single death can lead to the loss of a whole litter or nest, or the breeding adult of a pair of endangered species, which can put an already struggling population under significant pressure.
Another important factor that is often overlooked is that cats can carry harmful bacteria in their mouths. This is why if a person is bitten by a cat, they always need to be checked by a doctor. In our wild animals, cat bites frequently result in severe infections, which sadly, can rapidly result in death of these individuals if they are not found and treated quickly.
What diseases can cats spread to wildlife?
The main disease that cats spread in their faeces that is of concern to wildlife is toxoplasmosis. Cats are the definitive host for this protozoan parasite which they shed in their faeces. Toxoplasma is a zoonotic organism, meaning it can cause disease in people, especially those that are immunocompromised or pregnant women, but importantly it can also be transmitted to wildlife.
Red foxes ingest the parasite when they come into contact with cat faeces in the wild through contaminated water sources, vegetation or prey, such as rodents infected with the parasite. The parasite can be carried asymptomatically by many foxes, but in some individuals, it can cause neurological changes which can make them behave strangely and, in some cases, appear tame or behave unusually around people and environments which they should be fearful of. Similarly, European badgers can also ingest toxoplasma oocysts in the wild, and in some cases, this can lead to disease in these individuals as well.
How can we be kind to cats but also protect wildlife?
Cats are important members of many households in the UK and providing them with an enriching stimulating life is important for their health and welfare. Equally, wildlife is critical for maintaining a healthy biodiverse ecosystem, and with many species in decline, it is vital we do everything we can to protect it. Cats are certainly not the only or main factor causing a decline in British wildlife species – there are many other factors that are negatively impacting their populations. However, they can cause harm to a large number of species, and if we can limit the harm they cause, this can help improve population numbers, especially in those species that are already under great pressure from other factors such as habitat loss and climate change.
So how do we find a balance?
1) Supervise cats when they are outdoors
As discussed above, indoor cats or those using an enclosed ‘catio’ pose very little harm to wildlife. If your cat has direct access to the outdoors supervising them so you can intervene if they try to attack wildlife, or using a harness or enclosure such as a ‘catio’ can be useful ways to reduce the impact your cat has on wildlife
2) Model hunting through play
Playing with cats using specially made toys such as feather, bird and mouse toys which can be used inside the house to stimulate the chasing and hunting behaviour can satisfy this natural instinct in cats without them needing to act out the full behaviour on live animals
3) Limit the time your cat is allowed outdoors
Wild birds and mammals are often very active at dawn and dusk, with lower activity in the middle of the day. The exception to this is the breeding season where some species of wildlife, particularly garden birds, are often more active during the day than normal, as they try and find food sources for their nests. Limiting your cats outdoor time to the middle of the day and avoiding giving unsupervised outdoor activity in the times when wildlife is most active, such as the breeding season, can help in reducing the impact your cat has on wildlife.
4) Spay and neuter your cats
Feral cats are some of the biggest hunters of wildlife, as they rely on wildlife as a food source. Reducing the number of feral cats in the population is one of the best ways we can reliably reduce the impact of cats on wildlife. Many feral cats emerge when previously owned cats have unwanted litters, and those animals end up feral and breeding themselves. Neutering your cat will reduce the chance that they impregnate another female cat or become pregnant and have an unwanted litter.
Summary:
- Cats are the second most popular pet in the UK with an estimated 30% of UK households owning a cat
- Cats can cause significant harm to wildlife by causing injury or spreading disease
- Indoor cats or those that use a ‘catio’ system are much less likely to cause harm to wildlife
- It is possible to minimise the impact of cats on wildlife by making adjustments to the way we keep and care for our cats including adjusting the type of play they have access to, supervising outdoor time and neutering our pets
- Protecting British wildlife is essential to preserve a healthy diverse ecosystem and prevent species declining further and being lost altogether
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