Walkies, the seemingly innocuous duty of exercising the dog, has been identified as a huge threat to wildlife.

While it is held to be good for the health of owners by ensuring a daily dose of exercise, dog-walking can spell disaster for birds.

Numbers of birds in areas where people took their dogs for a walk were found to plummet by more than 40 per cent, according to a scientific study. Researchers also found that the range of bird species in dog-walking areas slumped by 35 per cent, especially among the easy-to-disturb ground-nesting varieties.

Cats, which are estimated to kill 27 million birds every year in Britain, are the traditional hate figures for bird lovers, but the research suggests that dogs could be just as big a threat.

Domestic dogs rarely succeed in catching birds, yet the study shows that they can devastate avian populations just by scaring them off. The researchers believe that birds recognise the dog as a top predator.

The “dramatic reduction” of the bird population was observed for up to 250 metres on each side of where the animals were being walked, and those bird species that remained in the area kept at least 10m (30ft) away from the paths.

The presence of people alone was recognised as a factor in disturbing birds but the impact was a fraction of that when the humans were accompanied by dogs. “Dog-walking caused a 41 per cent reduction in the numbers of bird individuals detected and a 35 per cent reduction in species richness,” the researchers reported in the journal Biology Letters.

“These results reveal that even dogs restrained on leads can disturb birds sufficiently to induce displacement.

“That the effects of dogs occurred even where dog-walking was frequent suggests further that local wildlife does not become habituated to continued disturbance.

“Ground-dwelling birds appeared most affected; 50 per cent of the species recorded in control sites were absent from dog-walked sites.”

The researchers, from the University of New South Wales, said the findings supported the idea that dogs should be banned from sensitive conservation areas.

While recognising the popularity of owning a dog and the “diverse benefits to human and canine health” from a walk, they said that their findings had detrimental implications for tourism.

“The dramatic reduction in bird diversity and abundance in response to dog-walking has immediate implications to other popular recreational activities pursued by humans,” they said.

“This includes bird-watching and ecotourism, where visitor satisfaction shows a strong relationship to numbers of species seen.”

The study was carried out in woodland on the outskirts of Sydney, Australia, but ornithologists said that the same effects took place in Britain. Research in Britain has shown that stone curlews, which are ground-nesting birds, abandon areas up to 400m from where dogs are walked.

John Clare, of the Royal Society for the Protection of Birds (RSPB), said that the Australian research “chimes in” with observations of bird behaviour in Britain where dogs are present.

“If you are walking your dog in a sensitive area for biodiversity, clearly it is having an impact,” he said.

In some circucmstances, he added, dogs can be more damaging to birds than cats. While cats catch millions of birds, they “aren’t a conservation issue” because they tend to kill young and sick specimens whereas dogs can disrupt avian breeding behaviour.

Dogs are banned from some RSPB reserves during the breeding season, but Mr Clare denied that the organisation was against the animals.

“It’s a widely held suspicion that the presence of dogs can be a disturbance,” he said. “We are not anti-dog. Many of our members have dogs, but we do restrict access to our land — we are a conservation charity.”

A spokesman for the Dogs Trust said: “It is possible that during breeding season ground-nesting birds could be disturbed and nests disrupted by uncontrolled dogs. Outside of this season the problem should be minimal as dogs are not generally known as birdcatchers.”

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