Our pets are devouring biodiversity but a few changes in EU law could make all the difference

Around 44% of EU homes have at least one pet, of which over 90% are cats or dogs. While we’ve been bringing more and more pets into our lives in recent decades, the trend really shot up during the COVID pandemic. Europe’s pet population rose by an estimated 11% in 2022 to reach 340 million in total, primarily cats (127 million) and dogs (104 million). As people take in more and more pets, they are increasingly concerned with protecting their welfare. At the same time, falling wildlife numbers mean we are also increasingly preoccupied with preserving biodiversity. These two concerns are not always easy to reconcile. While there is some overlap between wildlife preservation and animal welfare, there is a clear bias when it comes to weighing up the needs of domestic and wild animals – especially when the two interact. Miguel Ángel Gómez-Serrano My recent study identifies the key points of conflict between animal welfare advocates and nature conservationists. It analyses the ways in which the EU could reduce the impact of companion animals on wild animals. A feline colony on the outskirts of a village near Valencia city. The cats’ location and freedom of movement means they often interact with wildlife. Miguel Ángel Gómez-Serrano Conflicting legal frameworks The European Union has robust environmental legislation, with the Birds and Habitats Directives playing a particularly important role in protecting wildlife. In contrast, animal welfare legislation – especially that relating to companion animals – is much more recent, and effectively still in its infancy. Naturally, animal welfare only covers domestic species, leaving wild animals under environmental legislation. This imbalance has created a significant regulatory gap, particularly when it comes to the question of what happens when pets cause damage to wildlife. Read more: Good boy or bad dog? Our 1 billion pet dogs do real environmental damage Pets in the wild Pets that have the biggest impact on wildlife are those that become feral. Abandoned or escaped animals can form self-sustaining populations in the wild, with serious consequences for native species. Parrots that escape from homes are a good example of this. Species such as rose-ringed parakeet or the monk parakeet have established colonies in many European cities. Although there is a clear consensus that they are invasive species, their management presents a complex socio-environmental conflict. There is no doubt that parrots compete with native species for nesting sites and resources. But since they are a charismatic species, beloved by the public, measures to control their numbers often cause controversy. Monk parakeets (Myiopsitta monachus) nesting in the city of Valencia. Miguel Ángel Gómez-Serrano However, the feral pet that is the biggest source of concern is the domestic cat. Considered one of the most harmful invasive predators on the planet, it is responsible for around 25% of recent extinctions of reptiles, birds and mammals worldwide. Despite the evidence, there is still considerable resistance across Europe to recognising feral cats as an invasive species. This limits the legal options for managing their impact. Pets on the prowl Many domestic pets spend part of their time unsupervised outdoors. In the case of dogs, the impacts mainly take the form of preying on wildlife and disease transmission. Cats who come and go as they please are also predators, even when they are well fed. They particularly affect bird and small vertebrate populations in urban and suburban areas. Images from a camera trap showing a black-winged stilt chick (Himantopus himantopus) in its breeding habitat and, shortly afterwards, a cat in the same place, originating from an illegal cat colony located within a reserve area of Valencia’s Albufera Natural Park. The pair of black-winged stilts lost three of their four chicks in a few days at this location. Miguel Ángel Gómez-Serrano A particular case is that of cat colonies. Control of stray cat populations is usually the responsibility of EU Member States, resulting in widely varying approaches that range from the removal of animals to trap, neuter and return (TNR) programmes. Although TNR is socially accepted, scientific evidence shows that, in most cases, it is not an effective way to reduce cat populations or their short-term impact on wildlife. Government campaigns can reduce the impacts of feral cat populations. Here, a sign reading ‘do not feed the cats’ in a reserve area of the Albufera Natural Park, Valencia. Miguel Ángel Gómez-Serrano Dog walking Walking dogs in nature is a popular way to spend free time, and its growing popularity has led some areas to create designated dog beaches. This type of management is likely good for the health of pets and their owners, but not for wildlife. On natural beaches, for example, dogs can seriously affect ground-nesting birds such as Kentish plovers. Even when there is no direct predation, the mere presence of a dog can cause birds to abandon their nests or reduce incubation time, harming their breeding success. Above: A female Kentish plover flees her nest as a dog approaches, leaving her eggs unattended. Below: A pair of Kentish plovers stand by a dune protection fence while dogs walk along the beach. These dunes are a bird breeding area where pets are prohibited. Miguel Ángel Gómez-Serrano Animal welfare and conservation As biodiversity declines and the number of pets in European households increases, wildlife conservation and animal welfare advocacy are increasingly at loggerheads. We urgently need to reconcile these different perspectives and align their respective legal frameworks. The EU has legal scope to act. Environmental directives already force Member States to prevent damage to protected species, which could translate into clearer restrictions on the free roaming of pets, especially in protected natural areas. At the same time, the development of new animal welfare legislation offers an opportunity to reinforce owners’ responsibility, while also reducing the impact of freedom of movement and preventing them from being abandoned or becoming feral. The authorities need to get serious about the need to regulate the impact of pets, and pet owners need to be involved in preventing this impact. Only by doing this can we avoid a world where the only wild animals we see on our walks in nature are our own pets. A weekly e-mail in English featuring expertise from scholars and researchers. It provides an introduction to the diversity of research coming out of the continent and considers some of the key issues facing European countries. Get the newsletter!