Cats can impact local wildlife. As planting designer Nigel Dunnett says he wouldn’t have a cat, we look into whether cats are detrimental to a wildlife garden

By Molly Blair

Published: Tuesday, 11 June 2024 at 08:32 AM


According to a 2021 study by Cats Protection, there are almost 11 million pet cats in the UK. Considering this number doesn’t reflect stray cats, the actual number of cats is possibly much higher.

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An on-going debate around cat-ownership is our furry-friends’ impact on local wildlife. In an upcoming episode of Talking Gardens, the Gardens Illustrated podcast, planting designer and professor Nigel Dunnett told Stephanie that cats would never be allowed in his fantasy garden.

He said: “The one thing that’s banned from my gardens is cats.

Cats are killers and they take songbirds, and they take mammals, but they also deter and scare things away. So I really, don’t have cats myself, but I would really want my dream garden to be a cat free zone just to let other life exist without being eaten, chased or scared away.”

Is this opinion about the impact cats have on wildlife widely shared?

Given that cats are such popular pets, we decided to ask our followers on Instagram what they thought about cats and their impact on ecosystems.

Many people mentioned that cats had kept mice and rats that were causing problems for them under control


 
Of people that responded to our survey, 49 per cent were cat owners. 51 per cent said that they worried about the impact cats have on wildlife and 49 per cent said that their cat killed things in the garden.
 
One respondent told us: “I’m constantly compromised by my love of cats and wildlife. Hugo has a massive frilly collar and a bell.”

Domestic cat sitting in grass © David Tipling/Education Images/Universal Images Group via Getty Images


 
Another person said: “A menace. No other purpose than to kill wildlife and messy up the borders.”
 
Lots of people shared the opinion that cats killed birds, but several others mentioned that cats had kept mice and rats that were causing problems for them under control. Lots of people suggested that cats should wear bells on their collars or be kept indoors.
 
Fifty five per cent of people told us that they owned an indoor cat, and 49 per cent thought it was fair to keep cats inside. Lots of people responded saying that they thought restricting cats’ access to the outdoors or only taking cats out on a lead was one way of mitigating the negative effects of allowing cats to roam.
 
One person said “Indoor or supervised is the way to go.” While another responded: “Cats should be kept indoors, for the threat they pose to wildlife and for their own safety.”
 
With lots of the results coming in close to a 50/50 split, it’s clear that the debate on cats divides the crowd. 

What impact do cats have on wildlife?
 

A 2023 study published by the journal Nature Communications identified that globally, house cats eat 2,084 different species, with birds, reptiles and mammals making up around 90 per cent of the species consumed.

We don’t hear so much really about the damage that cats do from nature conservation organisations like the RSBP


 
Another study, published in the journal Landscape and Urban Planning in 2022 concluded that cats may kill between 160-270 million individual animals per year in the UK. It also suggested that more research was needed to determine the exact numbers and understand the full impact.

National conservation charities often come under fire from some who suggest that they don’t campaign against the impact of cats on wildlife to avoid alienating supporters.

This view has often been contradicted by organisations that say they are focused on wider scale problems affecting wildlife such as climate change and habitat destruction.

We asked the RSPB for their opinion on cats in gardens, and this is what their spokesperson said: “We know cats do kill large numbers of birds in UK gardens. Given the many pressures on our garden bird populations, from loss of habitat to the effects of climate change, we try to advise the public on ways to help reduce predation from domestic cats.

If you want to garden solely for the benefit of wildlife then not having cats should be something to consider

This includes fitting bells to quick-release collars and keeping cats inside overnight, as some of the simple ways cat owners can reduce the number of wild birds and other wildlife that their pets catch. We also encourage garden owners to help support birds and other wildlife through more nature-friendly gardening. For example, planting dense fruiting shrubs like holly and hawthorn can provide food and nesting sites for garden birds, as well as offering protection from cats and other predators.” 

It is undeniable that free-roaming cats kill wildlife, and if you want to garden solely for the benefit of wildlife then not having cats should be something to consider. Cat owners should certainly be taking steps to limit the amount of access their pets have to outdoor areas and habitats. However, this is a problem without a simple solution, and it’s a debate that is likely to continue for a long while to come.

Here’s more on why we need invertebrates in our gardens