Invasive species and the environment

When it comes to discussions about the environment, it’s almost always either reducing and recycling pollution (often plastic but sometimes cardboard and paper) or saving endangered species from humans. What I feel is lesser known is that animals can contribute to the extinction of a species or at least its endangerment, it could be the American mink but it could also be the humble housedog. Methods of culling are also controversial, that is if that invasive species is charismatic among many people like dogs and cats for instance.

American minks are creatures introduced to Europe and South America (especially Argentina and Chile) through the fur trade, which means they’re bred and domesticated for their fur. However they turn out to be rather adaptive to their new environments even to the point of wrecking havoc on native wildlife such as Britain’s water vole for instance. To worsen matters, some people deliberately release American minks thinking they’ll be freed from a life of misery, even if they make life a misery for other species like the water vole as we’ve mentioned before.

When it came to reintroducing the European mink (an animal more closely related to polecats and ferrets) to one Estonian island, people had to exterminate the American mink to make way for this animal and its population. Now supposing if we were to eliminate dogs from a certain island so that they won’t prey on seals, while this is good for the seal it’s a cause of anger for other people as they have a strong emotional attachment to dogs that seeing them as the invasive species they really are bothers them.

It’s already the case with cats when it comes to birds, it wouldn’t be any different if it were invasive dogs vs endangered seals and otters. But it’s also proof that humans aren’t the only animals rendering other species extinct and endangered, since cats and dogs have done similarly whether through predation (dogs have contributed to 11 extinctions and 188 species endangered) or disease transmission which can reduce a vulnerable species’s population either way.

There’s also some awareness of invasive species among pupils, at least in New Zealand where a teacher has taught them to identify and exterminate invasive predators off of some New Zealand locales. But I do wish there would be more of it to educate more people about the problem with invasive species and why they wreck havoc on the environment. Let’s not also forget that cats and dogs emit a lot of methane so cows and sheep aren’t entirely to blame either but not many people will admit this.

One such obstacle to minimising the impact of invasive species on the environment is that some people have a profound emotional attachment to their animals that they can’t see them otherwise or else they’ll get angry if you point them out that. That might be why accepting dogs as an invasive species is hard for other people, they can’t see them as that even when there’s evidence that they do wreck the environment through pathogens and predation.

There are also other ways invasive species can be introduced to the environment, it could be through trade and immigration like with cats and dogs (especially when they’re bought for hunting, guarding and pest control). It could also be due to cartoons and television like with raccoons in Japan, which sounds odd but that’s really how they ended up there. We need to discuss more often about invasive species so that we can educate more people about them and what to do with them at all in the future.

A sequel to what the fox doesn’t say

As I said before, fox domestication doesn’t entirely deconstruct dog domestication but mostly because dogs and cats aren’t commonly used for their fur the way foxes and minks are. That’s not to say there aren’t any people owning foxes and minks as pets or have them for practical uses like hunting and pest control, but then again Joseph Carter the Minkman might just be one of the very few people who use minks for pest control and hunting.

Let’s not also forget that despite their forcefulness, people who lead plant-based diets aren’t in the majority and fewer people still forgo use of animals other than pets altogether (there’s one self-proclaimed vegan on Reddit who admits to eating invasive animals so they’re not entirely animal free and they’re even a biologist in training). The number of pet fox and mink owners would be rather small, smaller than those who own ferrets and that’s saying.

To put it this way, globally speaking while ferret aren’t exactly one of the most popular or commonly owned pets in the world they’re still way ahead of foxes and minks in some regards. Much like cats and dogs, ferrets are also used for hunting and pest control. In fact, ferrets are used to flush out rabbits from their warrens. Dogs are also used to hunt rabbits and cats were also brought in Australia to get rid of rabbits (ferrets were deployed the same way in New Zealand).

While foxes are genetically and physically closer to dogs, in terms of anthropogenic usage foxes have more in common with minks (which they’re distantly related to, along with dogs and ferrets as they’re all caniforms), chinchillas and lynxes as they’re are used for fur. In fact, the usage of foxes for fur has been there before though the best documented case is in Canada where they’re used in commercial fur farms. That might be changing due to the growing ban on fur.

But then again, foxes aren’t that commonly kept for pest control and hunting the way cats, dogs and ferrets are.

What the fox doesn’t say about dog domestication

When it comes to a study on Prince Edward Island foxes, they were already exhibiting traits that were observed in Mr Belyaev’s study albeit a few decades ago and possibly older than that as foxes were domesticated for their use in fur farms in the late 19th century. I also think the other reason why this model of domestication doesn’t explain well for dogs in that many owned dogs in other countries are allowed to roam freely and while dogs can be and have been used for their fur, it’s not that common compared to what foxes go through.

The most common uses for dogs throughout history is that they’re kept alive and are used for hunting, pest control, herding and guarding. Even today, it’s still like that with many countries and communities to varying degrees. While dog meat does exist in some countries, even then most locals don’t necessarily eat dogs there (I’m Filipino and I don’t eat dogs myself). Dog meat is a thing in Ghana and Cameroon, but not all locals necessarily eat dogs and many more keep them for either hunting or guarding.

Likewise, many Chinese keep dogs for guarding and fighting and hunting to a lesser extent especially with regards to the history of Shar Pei dogs in China and Hong Kong. Actually it’s more parsimonious to say that dogs have more in common with cats and to some extent, monkeys than they do with foxes despite being more biologically related to them. For instance, cats, dogs and monkeys are commonly kept alive for things like pest control and hunting.

(Not only do macaques lead commensal lives where they thrive from being in close contact with humans without being deliberately domesticated but also one macaques species is domesticated to catch coconuts in farms.)

At some point in medieval Ireland (and was so in recent memory with Bodacious), cats were even kept for guarding livestock. It’s not that common but it did exist. Also both cats and dogs are even allowed to roam freely, they do so whether in the countryside (at least in Europe) or in slums, villages and farms as it is in Africa and Asia. Farm foxes are more commonly kept indoors, for want of a better word, though that’s not to say they’re allowed to roam freely just not to the same extent that dogs go through.

I even have a feeling that the very first dogs were practically semi-domesticated wolves in that while they were made to hunt prey by their owners and were fed by them, they also spent a good amount of their time left to their own devices when roaming and scavenging so I’m meeting the Coppingers halfway this way. I think there’s a reason why the Coppingers challenged Belyaev in his studies of domestic foxes (if they can be called such) is that foxes in Canada were already being domesticated for their use in the fur industry.

So these behaviours, physiological changes and mutations were already there if these surviving photographs and documentations are any indication. They could’ve been there earlier than that if foxes were deliberately domesticated for their fur, but it still proves their point that fox domestication was already a thing before Belyaev did his studies and he got them from fur farms so.

Not to mention, if fox domestication’s not a good model for dog domestication you’d be better off observing stray dogs which’s what the Coppingers did anyways even if they made mistakes in their research.

What is an invasive species?

An invasive species is pretty much any introduced species that has a negative impact on the environment, whether by competing with native wildlife for the same resources, predation, pathogens or interbreeding. They can be fur farm escapees as with American mink in Europe and parts of South America but they can also be common household pets like cats and dogs where with the latter, it’s been charged with endangering 188 species and rendering 11 more extinct.

(Dogs are considered an invasive species not only in Brazil but also in Russia and India despite being there in those countries for a far longer time than in Brazil, at least to my knowledge.)

Of all the animals used in the fur industry, only a few have become invasive to their new environments such as the Arctic fox and the American mink, both of which have been targeted by some hunters and conservationists for preying on native wildlife that with the former they were exterminated in some Alaskan islands and the latter got exterminated in one Estonian island. This is very controversial among animal rights activists, even if it’s needed to keep their numbers down to ensure the survival of others.

All invasive species are introduced but not all introduced species are invasive. Case in point would be the chinchilla, a mammal that’s also used in the fur industry but unlike the American mink it never became anywhere as invasive. While cats and dogs are both invasive species, hamsters and guinea pigs despite being introduced never became that invasive.

This is just a summary of what an invasive species is and can do to the environment, whether by predation, pathogens or competing with native wildlife over the same natural resources.

Endangered species and speciesism

I do think when it comes to endangered species, there’s also the unspoken element of speciesism in that some animals get saved because they’re considered cute, charismatic or well-favoured among humans and sometimes there’s a tendency to ignore animals that are even more endangered. The Ethiopian wolf population has declined significantly and down to the hundreds so there’s going to be a loss of genetic diversity but there are millions of dogs out there and most of them are mongrels so genetically and numerically speaking, they’re doing fine.

In fact, dogs are the third worst invasive species and if invasive species do outcompete native wildlife (the Ethiopian wolf’s only found in Ethiopia but dogs are all over Africa), then this has dire consequences for conserving Ethiopian wolves at all. Dogs are invasive in that not only do they hunt endangered species and risk endangered several others (African striped weasels in South Africa, Barbary macaques in Morocco and vervet monkeys in Uganda) but also spread diseases that kill other animals (lions and hyenas in Tanzania). This makes the situation of the Ethiopian wolves even more precarious.

As for striped and spotted hyenas, these two are nearly universally linked to witchcraft throughout Africa and South Asia that impedes whatever attempts at conserving their populations. Dogs and cats are also linked to witchcraft in Africa but only to a degree in tandem depending on the country and ethnicity (cats are linked to witchcraft in Southern Nigeria but tolerated and owned in Northern Nigeria due to religious differences), though many cats and dogs are owned in several African countries sometimes for practical purposes like pest control and some pest animals turn out to be endangered species so this complicates matter.

To put it this way, cats were brought to Cyprus for pest control this had noble intentions but who knows if a certain snake species went extinct because of that. Likewise with dogs, they could also be brought in for pest control but also risk rendering another species extinct at their expense. Dogs are beloved, certain snake species aren’t even if they’re more ecologically innocent in that they never become invasive and are relentlessly persecuted by humans. So there’s a better argument for speciesism, especially if some snakes have a worse reputation than dogs do.

The same could be said about amphibians, where some of them do inspire revulsion (as my father put it) and that complicates any attempts at conserving their populations when thought about this way. The mascot of World Wide Fund is a panda, not an endangered toad. That shows you the power of the charismatic megafauna, which can be detrimental to less cute species but there are attempts at addressing this when it comes to the Ugly Animal Preservation Society.

To summarise, some animals get prioritised not just for their closeness to humans but also their cuteness whereas others are despised for being pests even if they’re highly endangered and some are stigmatised for it, which complicates conservation efforts.

Good intentions ruining things

When it comes to the introduction of American minks in Europe, they were introduced for the purpose of providing fur to people. While I don’t necessarily approve of using animals for fur, the problem is that when these creatures are freed they wreck havoc on the environment by endangering native species through predation. The water vole, a semiaquatic rodent, is Britain’s most endangered mammal and some minks are small enough to hunt them down.

Freeing American minks from fur farms is a nice goal, but this also has them destroying the environment through predation that I think it’s much more sensible to not bring them over to Europe in the first place. It might be possible to use American minks for more practical and less destructive ends such as making them hunt vermin as one man (Mink Man and his minkery) does. But then again, mink ownership’s not that popular and ferret ownership’s already not that popular either.

The only real difference’s that ferrets have a longer history of being domesticated especially in the Mediterranean where they’re used for not only hunting but also pest control. That doesn’t mean ferrets are more saintly as they’re known to be an invasive species in Ireland and New Zealand, wrecking havoc on native wildlife and reproducing there (though I think dogs are even more destructive than ferrets because there’s more of them around).

If I’m not mistaken, ferrets were introduced with the goal of hunting down rabbits but they ended up hunting native birds so you have attempts at culling them in New Zealand. New Zealand aims to be predator free in 2050, so it’s finding ways of exterminating vermin. But if I’m not mistaken, there are people who think that ferrets are unfairly targeted which complicates some people’s goals of having a predator free New Zealand.

Likewise, I think the major barrier to realising that dogs are an invasive species is probably people’s own emotional attachment to them even when there’s plenty of evidence that dogs do negatively impact the environment through pathogens (this killed off lions and hyenas in some African countries) and predation. You have dogs killing wildlife, eating sea turtle eggs and giving diseases to endangered species such as Ethiopian wolves.

With Ethiopian wolves, there’s not a lot of them around whereas there are far more dogs out there so the argument that dogs are an invasive species in the entire African continent makes the most sense. They’re deliberately introduced by humans from trade with Israel and used for good purposes like pest control and guarding, but they got out of hand whenever they prey on native wildlife such as African striped weasels, Barbary macaques and vervet monkeys.

They even spread diseases that endanger lions, hyenas and Ethiopian wolves so the argument’s strong in this one. Many of the same things can be said of domestic cats in Europe and Asia, being introduced from Africa and Anatolia. These two are the most commonly owned and used carnivorous mammals and they’re very destructive to native wildlife.

There’s even a case study by Karen Lupo where hunting dogs ended up attacking animals other than game so the potential to be an invasive species is there despite the good intentions. When it comes to introducing invasive species, sometimes the road to hell’s paved with good intentions that gets out of hand.

Why dogs are an invasive species but not horses

As to why dogs are an invasive species and the third most destructive after cats and rats but not horses has to do with that not only have dogs preyed on 191 species and rendered 11 more extinct but also transmit diseases and pathogens to endangered animals such as lions and Ethiopian wolves and also compete with native wildlife over the same prey where there are cases of dogs stealing prey from lynxes and one recorded instance of a snow leopard guarding its prey from the dog. While horses are introduced, their impact on wildlife’s either unknown or minimal compared to that of dogs.

There’s actually a growing body of studies showing that dogs do have a detrimental impact on wildlife, though I wish many more people are aware of the damage they do to wildlife if only more knew about it. Though I’m afraid only some people and some countries take this seriously, either because they still have feral dogs or because they’re more aware of it on some level as to dedicate studies about this. (I tried talking about this on Reddit but I think with countries like Brazil and Argentina, not only do they have more stray dogs or rather owned dogs roaming freely but also a greater awareness of their predation.)

If Brazil and Argentina are more aware of dog predation, it would make sense that they’d prey on more endangered species there than they would in Canada and America which their effects on wildlife aren’t that extensively studied to that extent. It’s also highly possible there are Canadians and Americans who’re aware of dog predation but not a lot to publicise their findings the way the Brazilians and Argentinians do, but there’s a growing awareness of it and why dogs are invasive but not horses.

On feral animals and predation

When it comes to some feral predators and their impact on the environment, there are cases where they can drive some species seriously endangered and others extinct. In the case with dogs, they caused 11 species to go extinct and when one of my former dogs hunted and ate frogs, my father said that they’re at risk of becoming extinct or something like that. It’s not speciesism if dogs and cats are invasive species, that’s calling a spade a spade when it comes to their impact on the environment. There are also other ways they invade the environment is through transmission of diseases such as dogs transmitting rabies and distemper to Ethiopian wolves.

(That’s why I think dogs are practically an invasive species in Africa: they’re not native to the continent, spread diseases to an endangered canid and prey on endangered species themselves.)

Consider this: if humans are murderers for hunting endangered species, wouldn’t the same thing be said of cats and dogs? If humans are guilty of genocide, then so are cats and dogs. You shame one but ignore or excuse the other two. Actually there have been some humane attempts at addressing cat and dog predation of wildlife, whether if it’s by keeping them indoors or feeding them right (as in one Chilean study). This also applies to other invasive mammals like ferrets and foxes, which are both invasive to New Zealand and Australia respectively and are guilty of murdering wild animals as humans do.

Then again, when it comes to the deliberate introduction of invasive animals it’s paved with good intentions. Ferrets were brought into New Zealand for pest control, but this got out of hand when they became vermin themselves hunting native birds wherever they went and reproduced. It’s likely the same with cats and dogs especially when they’re brought in for pest control and guarding where in some cases this worked to their advantage but in other cases they ended up hunting vulnerable species.

There’s a Chilean study stating that the owners whose dogs strayed said that they hunted native (Chilean) hares, but it does worsen matters when native wildlife are seen as vermin to some people when it comes to their livelihoods that they’re going to use cats and dogs against these animals they hate. Now here’s a better argument for speciesism, especially when it comes to endangered species being maligned by the public. Something like certain bats being maligned by people whereas dogs are considered beloved. These bats might have their numbers lowered, but the dog’s not in danger of becoming endangered and moreso for mongrels.

(If most dogs are mongrels, there’s still a lot of genetic diversity to be thankful for.)

The Ethiopian wolf’s something one should be worried about, not only is it the rarest canid but also the one with the greatest risk of inbreeding (this could’ve happened to the cheetah at one point). Dogs aren’t in danger of losing their numbers, mongrels especially have great genetic diversity and many reproduce a lot. Ethiopian wolves, however, risk being endangered by dogs whether through genetic dilution or transmission of diseases and pathogens as well as competing for the same prey.

If a dog hunts at will, there’s the risk that it can endanger species especially if their numbers get lowered that it’s a cause for alarm and fear when a dog does it at all though the same thing can be said of the cat.

An honest talk about invasive species

When it comes to invasive species, it’s not just that they’re non-native to the environment but also negatively impact the environment whether through predation, pushing species to extinction in general or spreading pathogens and diseases that scientists are currently trying to please some people through more humane means of pest control. They are already bending over to the whims of people who don’t want certain animals getting killed, whether if it’s keeping pets indoors (actually they should do the same to dogs as they negatively impact wildlife through hunting and general disturbance) or sterilising/neutering them.

There are practically two ways invasive species become this way, first are those who’re deliberately introduced sometimes for noble reasons like pest control where ferrets in New Zealand were brought in to kill rabbits before killing native wildlife themselves. Second are those that are accidentally introduced and wreck havoc on wildlife like with mice and rats for instance, especially whenever humans travel by boat or if they’re released by accident. When it comes to a country like Germany, that’s one of the European countries where raccoons and raccoon dogs were introduced however for their fur but once something got bombed that’s when their populations started exploding and when they wreck havoc on native German wildlife.

New Zealand’s another country where you have not one but three mustelids wrecking havoc on native wildlife, you have stoats, weasels and ferrets brought over there sometimes for pest control and they ended up becoming pests themselves. Ferrets were at some point raised for their fur but they quickly became major pests that not only kill native New Zealand wildlife but also spread diseases to cows. As for cats and dogs, they’re the most common invasive mammals to date where they’re noted to prey on wildlife and spread diseases to endangered species like the Ethiopian wolf. There’s even a growing body of work about the damage dogs do to wildlife, whether through predation, general disturbance or disease.

(Though I still wish people would keep dogs indoor to keep them from disturbing and hunting wildlife, however some people like some German hunters are aware of this to some extent.)

Not all nonnative species necessarily become invasive as with cows, sheep and horses but those that do render species severely endangered and compete with native wildlife. Feral goats are an invasive species for rendering some plants endangered, wrecking havoc on the ecosystem and there are attempts at culling or hunting them to keep them from spreading. Feral hogs not only destroy the ecosystem through their habit of rooting but also hunting native wildlife and that they emit a lot of carbon dioxide and methane. You already have people attempting to hunt these creatures, or cooking them as meat. There are people who try to turn some invasive species into food, the best they can do about it.

But the fact remains that some species do wreck havoc on wildlife through their interactions with them (general disturbance, hunting, rendering native plants extinct or endangered, sharing pathogens).

Types of invasive species

When it comes to invasive species, it’s practically any introduced species that has a negative impact on native wildlife and ecology. They could be the accidental variety such as rats (both brown and black) and mice as well as zebra mussels, but they could also be intentional as is the case with cats, dogs, foxes, ferrets and rabbits. If I’m not mistaken, when it comes to Australia foxes were brought in to be hunted down by people and in New Zealand ferrets were brought in to hunt down rabbits but both became invasive species themselves. The most successful invasive mammals are practically cats and dogs, which are both common companion animals and have hunted down some species to extinction or rendered at risk for extinction.

(My father had to install fences because one of my former dogs was killing frogs a lot to the point where he said that he’s making them extinct or something and said that he’s destructive.)

Of all the canids and caniforms in Africa, only the dog’s not native there and to give an idea of their negative impact on wildlife not only do they transmit rabies and distemper to Ethiopian wolves in Ethiopia but also prey on vervet monkeys in Uganda and Barbary macaques in Morocco. As an invasive species, not only did the domestic dog compete with the brown bear in North Africa but also spread more rapidly as much as the brown bear found itself extinct in the 19th century. That’s why the dog spread to throughout all of Africa but the brown bear went extinct in North Africa, if invasive species do outcompete with native wildlife this does have grim implications for conservationists trying to preserve any native species left.

This is also why the domestic cat spread throughout Eurasia and Africa, though at least one landrace’s native to Africa while its wild relatives declined in numbers and there’s a paper somewhere about cat predation of amphibians in Cameroon. As to why these two are the most successful invasive mammals has to do with their close association with humans, especially whenever humans travel and trade that’s when cats and dogs spread to Eurasia and Africa for better or worse. At other times, the elimination of native wildlife might even be deliberate especially when cats and dogs are used for pest control that’s when things get murky.

In the case with ferrets in New Zealand, their introduction was paved with good intentions when it comes to regulating rabbit populations. However, this got out of hand when they started preying on native wildlife (a good number of them are flightless birds) that you have ferrets getting banned as pets in 2002. They’re also an invasive species in Ireland, where a feral population has been established and noted to prey on native wildlife as well. As for raccoon dogs, they’re one of those invasive species that were introduced for fur but got out of hand when released (whether independently or by people) that they wreck havoc on native wildlife as well.

The only difference between them and cats, dogs and ferrets is that the latter three all have any real practical use and value for centuries (since all three of them are used for pest control such as rats) that they could easily be rehomed and given human owners but since raccoon dogs are only used for fur, culling feral populations is the only option around. Admittedly, culling’s very controversial among animal rights groups because that involves killing animals especially when they get out of control. As for the accidental invasive species, these are the rats and mice of the world.

They go with humans whenever they sail by boat (that’s the case for centuries) and wreck havoc on native wildlife, whether if it’s eating hatchlings or competing with native rodents and wildlife. That’s practically the same thing with zebra mussels and other accidental invasive species, especially when dogs accidentally open up opportunities for them to invade native wildlife. You have the category of intentional invasive species, especially when they’re brought in by trade and immigration when it comes to noble goals like pest control but become pests themselves as well as the accidental variety when humans go and move about.