The Rat, Cat, and Dog Problem

Semi-feral dogs are increasingly disrupting ecological systems in nature preserves all over the world, threatening vulnerable and endangered wild animal populations by killing livestock and transmitting disease.  From The Washington Post:

How the dog became one of the world’s most harmful invasive mammalian predators is as much a global story as a Brazilian one. Over the last century, as the human population exploded, so did the dog population, growing to an estimated 1 billion.

That has been great for people — and even better for dogs — but less so for nature, according to a growing body of academic research implicating canines, particularly the free-roaming ones, in environmental destruction.

The global impacts of domestic dogs on wildlife are grossly underestimated,” researchers concluded in a 2017 study published in the journal Biological Conservation. The researchers, based in Australia, convicted dogs in the extinction of 11 species and declared them the third-most-damaging mammal, behind only cats and rodents....

It was found that the closer humans lived to a nature preserve, the more likely dogs had penetrated it.

But perhaps most striking? The dogs were neither feral nor domestic — but somewhere in between.

“All the dogs we detected had an ‘owner’ or a person that the animal has a bond with,” Paschoal said. “The species population increases following human populations, exacerbating their potential impact on wildlife.”

In short, the quasi-feral dog problem is the same as the feral cat and brown rat problem -- two other species rarely found far from humans, but which decimate wildlife wherever humans penetrate forest and field.

We poison rats, and now we are engaged in wholesale poisoning of feral cats in Australia and New Zealand. Can dogs be far behind? Why should they be an exception?

One thing seems obvious:  killing dogs alone will not stop the problem as dogs breed rapidly and new dogs will simply be acquired or move into an area.  Fencing, combined with poison and free spay-and-neuter laws, however, will not be a quick fix. 

In the US and Europe, when we faced similar problems, we turned to dog catchers who were paid a bounty, and these catchers were paired with rapid-kill systems (drowning dogs in cages, gassing, shooting). 

If you think that system is not still in place today, I urge you to visit your local dog pound.