One of the perennial problems for some hikers is off-leash dogs on the trail. It’s bad for wildlife, they say. Others say it’s no big deal.
So what do we know about off-leash dogs and their impact on wildlife? It turns out that it can be surprisingly difficult to pin down specifics, but experts tend to agree on some general points.
Dogs attacking wild animals
In general, it seems true that domestic dogs can pose a threat to wild animals.
“Some dog owners will characterize it as, ‘oh, they’re just having fun,'” says Mike Weston, a conservation biologist at Deakin University in Australia. “But if we can put ourselves in the perspective of the wild animal […] if he doesn’t escape effectively, he’s probably dead or injured, right?”
Experts also say it’s common to hear even well-trained dogs suddenly and unexpectedly rush after an animal. Dog feces can also spread diseases or parasites.
Even if a dog doesn’t directly harm or make wildlife sick, it turns out that just their presence — the sound of their barking and their smell, for example — can affect wildlife.
Domestic dogs increasing wildlife stress
In 2008, a group of researchers showed that deer, squirrels, rabbits, and prairie dogs stayed off trails in areas where dogs were allowed. others studies found that the presence of dogs can increase stress levels in wild animals.
This can cause problems as stressed animals may have trouble finding food or breeding and raising young. This is particularly worrying if the species’ population is already struggling.
“Many species are severely limited by the amount of habitat they have available. So if we take chunks out of it and make it less suitable, that could be a big deal for the population,” says Courtney Larson, a US-based conservation scientist. Nature conservation which studies how recreation and conservation can sometimes be at odds.
Weston in Australia has also seen how recreation can build habitat.
Some Australian beaches are home to the nesting grounds of a dainty little shorebird known as the hooded heart. Authorities would like to protect the birds, but they often put them down in a tussle with local dog walkers.
Dogs can scare and even kill birds. In 2019, Weston and his colleagues did research involving the use of GPS trackers to see what kind of beach a dog would walk on.
“The amount of beach left for animals that weren’t around a dog was very, very small,” says Weston.
Of course, specific impacts can vary widely from place to place, as not all animals may react in the same way. Deer, coyote and bird can react differently to nearby dogs, Larson says.
However, there may be good reasons for conservation authorities to try to limit the presence and impact of dogs in an area.
A dog on a leash strikes against a relaxed dog
Still, questions remain about how much worse off-leash dogs are than leashed dogs in the wild. This was harder to measure with hard science.
Few studies exist on the topic, and those that have been done present mixed conclusions. Some studies suggest that leashed dogs are particularly impactful while others found that dogs tend not to stray as far from their humans when off-leash.
Oddly, part of the reason for this paucity of data may be due to people walking dogs off-leash. In many areas, a large number of people ignore the leash regulationswhich can make it difficult for researchers to find what you might call “clean” data sets to compare with each other.
Unfortunately for dog walkers, this lack of compliance can eventually come back to bite them, warns Weston. This is because the alternative to a “leash only” regulation could be a “no dogs at all” regulation.
Weston points to one park in Australia where, after about 20 years of trying to run off-leash dogs, the authorities eventually banned dogs altogether.
“I would consider this a bad outcome for all parties, including dog walkers and especially responsible dog owners who were actually on a leash,” says Weston.
Other reasons to leash your dog
Dog owners may want to keep dogs on a leash for other reasons as well.
While many animals may perceive dogs as predators, there are some that may perceive them as prey. This could include black bears, mountain lions and coyotes – or even hunters of people who mistake it for a domestic dog for an animal they are chasing.
Some public lands allow hunters to set traps for animals that can catch a dog. And dogs can potentially get hurt or sick from things like running into cars or drinking contaminated water.
Many parks may also want to keep dogs out of certain areas due to construction, fragile vegetation (even in deserts) or restoration projects. Some people on the trail may also be afraid or allergic to dogs.
Ultimately, experts recommend that people who want to walk their dogs look up and know the regulations ahead of time and follow them. Some places will allow dogs to roam freely. Others may not be.
“While there are many national parks for people and little ones to explore, it’s important that visitors check to see if they can bring their dog along on their adventure,” said Cynthia Hernandez, spokeswoman for the US National Park Service, which also pointed out online map of national parks that allow pets.
Ultimately, we need more data on the effects of running a dog off-leash, and there may be places where this is good. But there are also very good reasons to keep them with you on a hike. “We have to be careful,” Larson says.