Dogs as a danger to wildlife


Domesticated dogs tend to be widely loved as companions and I am no exception to this feeling. Hence I was startled to learn that feral and free-roaming dogs may be responsible for the extinction of a large number of animal species.

There are now an estimated 1 billion domestic dogs across their near-global distribution.

Domestic dogs include feral and free-ranging animals (such as village and camp dogs), as well as those that are owned by and completely dependent on humans (pet dogs).


We found that dogs are implicated in the extinction of at least 11 species, including the Hawaiian Rail and the Tonga Ground Skink. Dogs are also a known or potential threat to 188 threatened species worldwide: 96 mammal, 78 bird, 22 reptile and three amphibian species. This includes 30 critically endangered species, two of which are classed as “possibly extinct”.

These numbers place dogs in the number three spot after cats and rodents as the world’s most damaging invasive mammalian predators.

Aside from simply killing animals, dogs can harm wildlife in other ways, such as by spreading disease, interbreeding with other canids, competing for resources such as food or shelter, and causing disturbances by chasing or harassment. For example, contact with domestic dogs increases disease risk for endangered African Wild Dogs in Kenya.

Part of the problem is that when wild animals perceive dogs as a threat, they may change their behaviour to avoid them. One study near Sydney found that dog walking in parklands and national parks reduced the abundance and species richness of birds, even when dogs were restrained on leads.

I am glad to report that Baxter the Wonder Dog has not killed any animal, though he does vigorously bark and chase after squirrels, rabbits, and birds that come to our garden.

Comments

  1. says

    These numbers place dogs in the number three spot after cats and rodents as the world’s most damaging invasive mammalian predators.

    So that should actually be the number four spot? They seem to have left the obvious number one invasive mammalian predator off their list.

  2. kestrel says

    Wow – that’s pretty interesting. I knew that dogs were killers of livestock but did not realize that their impact includes wild animals as well.

    I myself was nearly killed by dogs. They had packed up and were killing my livestock; when I ran out there to protect the livestock, the dogs began to stalk me. If I had not had my rifle with me that day, I would not be typing this now. They were all pet dogs; every one had a collar and one was even sporting a nifty bandana. About three weeks after I had that experience (which was pretty harrowing) a woman in Colorado was killed by dogs when she went out to visit her horse at a boarding barn out in the country.

    I think we tend to forget that dogs are very efficient predators and can bring down an animal larger than they are.

  3. Mano Singham says

    kestrel @3,

    It is shocking that caregivers of the dogs would let them roam so freely if they were so aggressive.

    There was a woman in my neighborhood who was killed by a pit bull that had been allowed out without a leash. This led to a move to have the city ban the keeping of pit bulls as pets but that was defeated.

  4. efogoto says

    @4 Mano: Various family members of mine have dogs. When two of my siblings visited my mom’s house, they brought along their dogs and put them in the back yard with my mom’s dogs. The bunch of them set on my mom’s cat, who until that time had gotten along fine with mom’s dogs … but darn near got killed then, incurring a hefty vet bill. Individually, nice dogs that all got along with the cats in their homes. As a pack, they were vicious.

    “It is shocking that caregivers of the dogs would let them roam so freely if they were so aggressive.” Individually, they probably weren’t aggressive.

  5. Santwana Tewary says

    Wow!! Who will mention the species topping the list?
    Humans are the most notorious and invasive of all and still their research points out poor innocent cats, rodents & dogs……..mind boggling actually.

  6. kestrel says

    Must agree with efogoto, #5: the dogs were perfectly ordinary pet dogs. They were not “monster” dogs – just as a human who attacks another is not necessarily a “monster” although we like to tell ourselves that… Many, many people allow their dogs to roam free, not understanding dog behavior and having some kind of odd, Disney-esque idea that all animals should be free to roam as they will. Unfortunately this can, and often does, end in tragedy.

  7. jazzlet says

    Lofty
    Humans are never dog pack leaders, dogs know perfectly well that we are a different species. Besides that the original work that lead to the ‘Pack Leader’ theeory was done on a constructed wolf pack, not a natural wolf pack, and has been entirely discredited, as well as repudiated by the researcher that published the original study. Natural wolf packs are based on the family unit.

  8. jrkrideau says

    @ 2 kestrel

    I knew that dogs were killers of livestock but did not realize that their impact includes wild animals as well.

    Where I grew up, the game wardens were always hunting Skippy the family pet in the winter. Heavy snow slowed down and exhausted the deer. There are few (no?) domestic animals more than 100 metres from the barn so they are usually safe.

    My sister and husband who live in the same place where I grew up have seen packs of as many as 6–8 dogs go by, a bit too fast or too far away for my brother–in–law to get a decent shot.

    And like your pack these were pets. We even know where they come from but could not identify the specific dogs in the village for the Wardens to seize, and no one has gotten a clear shot at them as they lope by.

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