DOG poo forms a major part of the diet of red foxes living in pine forests in the Scottish Highlands, a study has found.

The research has found that foxes living in wooded areas of the Cairngorms mountain range actively “hunted” dog faeces – most likely left behind by walkers out on rambles with their pets – when their wild prey was scarce.

The academics have found for for the first time that dog faeces makes up a significant part of foxes’ diets, and contains roughly the same amount of calories as wild prey.

But the researchers say the poo is much easier to "hunt" - with the foxes feeding on it especially when wild prey is scarce.

The scientists at the University of Aberdeen’s School of Biological Sciences, the Laboratory of Alpine Ecology at University of Grenoble Alpes in France, Forestry and Land Scotland and the land management partnership Cairngorms Connect believe it is also the first time such a connection has been detected between the two species, and provides fresh evidence of the impact of human behaviour on wild animals.

The study had initially set out to examine the diets of foxes and pine martens, which have very similar eating habits, but resulted in an unexpected discovery instead.

Using a technique known as “metabarcoding”, which is based on DNA identification, the researchers found that domestic dog DNA was the second most frequent species in fox stool samples, making up nearly 40 per cent.

Several theories were considered as to why this was the case, including a possible confusion between fox and dog DNA since the two are closely related.

The Herald:

The authors of the study concluded that dog faeces has become an important food source for foxes to fall back on in times of scarcity, and shows the knock on effect of human activity in wild parts of the UK – in this case, dog owners walking their pets.

Cristian Navarro, a PhD student from the University of Aberdeen’s School of Biological Sciences, who co-authored the study, which was published in the journal Ecology and Evolution, said: "The fact that foxes consume dog faeces in the amounts we have found is unprecedented.

“Rabbits and other related species are well known to consume their own faeces, but consumption of the faeces of another species has seldom been documented and likely represents an overlooked interaction among wild animals.

“This phenomenon would be undetectable through traditional diet study methods, but by using DNA-based techniques, our study has revealed this interaction for the first time, leading to important questions about how human activities are affecting wildlife.”

They researchers warned that the availability of dog faeces and its consumption by wild animals creates risks of disease and parasite transmission, and of introducing new pathogens.

Another of the study’s co-authors, Professor Xavier Lambin, added: “Just like how bird feeders in gardens benefit some species of birds while others are displaced, dog faeces may benefit foxes over their competitors or prey species.

“In addition, the availability of dog faeces and their consumption by wild animals creates risks of disease and parasite transmission, and of introducing new pathogens.

“This highlights the need for a holistic management approach, including the need for measures to help ensure the appropriate use of outdoor spaces by dog walkers, given the potential impacts.”

According to the Scottish Wildlife Trust, the foxes in the uplands tend to be larger than the rest of the UK.

Most foxes weigh between 12-15lbs and the largest fox ever recorded – found in the Scottish Highlands, weighed a whopping 26lbs.

It is believed that upland foxes are larger than lowland foxes because higher latitudes in Scotland and Scandinavia have long winter nights. Because foxes are primarily nocturnal it allows for a longer hunting period.

If a fox can hunt more they will inevitably catch more and thus grow larger.