Posts Tagged ‘invasive species’

I love Kentucky Afield, but I have some problems with the terminology in this clip.

The hunter in this video calls the coyote an invasive species in part because it killed some cats.

Now, cats clearly are an actual invasive species. They exist at much higher densities than any native mesopredators, and the truth is that anything that keeps cats numbers down or keeps them scared out of their minds to leave the house is a good thing for many small birds, mammals, reptiles, and amphibians.

The genus Felis is not native to any place in the Americas. Had Europeans never come over here, we would have our native cat species, which would exist at numbers that were controlled through competition with other native predators and the fluctuating numbers of prey species.

If any animal that has been introduced since the time of colonization has caused ecological chaos, it is the domestic cat.

This is what ecologists say, but cats have good publicity.  They have a fan club. I can’t say that I’m in it, but I can see why some people like them. They are like a mentally deficient dog that doesn’t require walks or much training, but they are far more intelligent than guinea pigs and better company than Syrian hamsters.

The same cannot be said for the coyote. Those of us who live outside the proposed original range for coyotes tend to think of them as a Western species that came into the East, but the truth is we have fossil evidence of  Pleistocene coyotes in the East, including in West Virginia.

We also have accounts of anomalous wolves. For example, John Smith described the “wolues” around Jamestown as not being much larger than English foxes. It is usually suggested that these Jamestown wolves were red wolves. Ignoring the real problems about what red wolves actually are, coyotes fit the description far better than anything we’ve ever called a red wolf.

Henry Wharton Shoemaker also wrote of a small brown wolf that was common in the Susquehanna Valley, which he contended was exactly the same thing as the coyote.

It is very possible that coyotes existed in the East but in far smaller numbers than they do now. The wolf hunters and fur trappers who came into the continent took as many wolves as they could, and they didn’t take great lengths to catalog what they were killing. They just killed them, and they either got their bounty or sold the hides.  And many Native American dogs went with them.

So I think it is possible that there were some coyotes in East, but their big range expansion didn’t happen until the extirpation of larger wolves.

Further, the entire genus Canis has its origins in this continent.  The earliest forms of the genus was Canis evolved in North America 6 million years ago, though they were restricted to the Southwest and Northern Mexico, but coyotes and coyote-like canids were found throughout what became the United States during the Pleistocene.

The genus Felis didn’t appear here until permanent European colonization and settlement.

So this idea that you’re killing the coyote as the “invasive species” to protect the cat is a total perversion of the ecological concept.

It is also interesting that no one ever calls a red fox an invasive species in the United States– with the except of Eastern red foxes that have been introduced to California. The red fox was not found south of the Northern Great Lakes, Northern New York, and Northern New England, but it is now found over most of the Eastern states.

It was originally claimed that it derived from English imports, but recent genetic analysis and historical research have found that red foxes in the East and South descend from those foxes that wandered south from Canada and the northern tier of states.

The red fox took advantage of the clearing of forests, which disadvantaged the gray fox, its main competitor, and came south in large numbers. They introduced themselves to the new territory in the same way that coyotes would later do as the wolves were killed off.

No one seriously considers the red fox to be an invasive species. It also has a record of being in parts of Virginia and Tennessee during the Pleistocene, but it did not exist when Europeans came.

Most states treat it as a proper game animal. Mine has a proscribed hunting and trapping season for them, but coyotes can be killed all year round.

But the “native” status of the two animals is fairly similar, and if these older accounts of anomalous small wolves in Pennsylvania and Virginia describe coyotes, then the coyote has a much stronger native status than the red fox.

“Invasive species” is a term that really does have a meaning to it, but it cannot be allowed to be used in such a way that it means any animal that inconveniences us.

We should use that term to mean animals that were introduced either by accident or intention and that have caused real ecological damage. I am thinking feral hogs here. And cane toads. And marmorated stink bug.

And yes, feral cats.


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It is well-known to readers of this blog that I am ultimately quite contemptuous of the animal rights movement.

And after reading William Stolzenburg’s Rat Island: Predators in Paradise and the World’s Greatest Wildlife Rescue, I’ve become even more so.

Stolzenburg is one of the best writers about ecology who writes for a general audience. His previous book, Where the Wild Things Were, carefully chronicles the scientific discoveries that have shown that large predators are a great asset to ecosystems. In a world where human activities have so severely pared back the ranges of so many large predators and forced some of them into extinction, ecosystems are now suffering great imbalances.  These imbalances include overpopulation of grazing or browsing species– such as the overpopulation of white-tailed deer in North America– and a phenomenon known as “mesopredator release,” when smaller predators are able populate a region in much higher numbers now that they no longer suffer from predation or competition from large predators. These smaller predators target different species than the larger ones do, and these prey species have issues sustaining themselves.  For example, when the Yellowstone ecosystem lost its wolves, coyotes began to increase in number. Coyotes target pronghorn fawns and their mothers, so with more coyotes around, the pronghorn numbers collapsed. Wolves rarely target pronghorns– not enough meat on them– but they do keep the coyotes in check.

But in Rat Island, Stolzenburg examines another perhaps even more severe issue affecting wildlife conservation:   invasive species. More specifically, he examines how invasive species are destroying island ecosystems. Mass extinctions have been occurring on islands all over the world.

And almost all of them can be blamed upon either human profligacy or species that humans introduced.

These islands are less than 5 percent of the world’s landmass, but on them dwells 20 percent of the world’s species.

The peculiarities of island biogeography make them great incubators for relatively rapid evolutionary change. Whenever a population of organisms winds up colonizing one of these islands, it is always small, which means the founder effect version of genetic drift is always evident. Further, because islands are isolated, selection pressures that result from competition from lots of other organisms and from predation are simply not there. Many islands wind up with populations of large flightless birds that derived from ancestors that were blown to the islands as they were flying.

Some places wind up with avian predators, such as the Swamp harrier, the morepork owl, and the New Zealand falcon, but had no terrestrial mammalian predators. One species of parrot, the kakapo, evolved under these selection pressures. It became an enormous flightless parrot, weighing over 8 pounds at maturity. It is the world’s heaviest parrot, and because it had to worry about only avian predators, it evolved to be green to blend in with the foliage. And its entire predator avoidance behavior is simply to stand still.

That strategy didn’t work so well when Europeans began introducing cats, weasels, stoats, and ferret/polecat  hybrids to New Zealand. When they came across the kakapos, the kakapos didn’t recognize the danger, and if they did, they merely froze in hopes the predator wouldn’t see them. Which was great news for these predators!  A big, fat parrot that just stands  there when you come after it is bound to be a choice item on the menu.

And today, kakapos exist in very finite numbers. They are all heavily monitored and guarded from any potential threats.

As man’s commerce has brought him across the planet, he has brought with him a retinue of domestic animals that readily go feral and any number of species that scavenge on the margins of human civilization that are also fairly adept at hitching rides of ships. We’ve introduced cats all over the world, and rats comprising three distinct species have been spread hither and yon.

We’ve also intentionally introduced species to islands. The Russians used to sail by the Aleutians on their way into Alaska and down the Pacific Coast in search of sea otters. To augment their sea otter hauls, which were starting to decline in towards the end of the eighteenth century, they released arctic foxes onto the islands. The foxes would live wild on the islands, feeding on the vast hordes of sea birds, and the Russians would trap them for their fur. The assumption was that the arctic fox would be a self-sustaining population– a sort of free range fur farm.

The foxes proved to be a disaster. They thrived on the islands, but as their numbers increased, they destroyed the rookeries of seabirds and waterfowl.  An endemic subspecies of cackling goose very nearly became extinct, and it was saved only when the foxes were eradicated on some of the islands.  The world’s smallest species of auk, the least auklet, has vast colonies in the Aleutians that are so large that they are very difficult to count or estimate. The foxes also made short work of these birds.

To save these birds and other wildlife, conservationists all over the world have resorted to using lethal force against them.

Arctic foxes have been trapped off of 40 of the Aleutian Islands. A celebrated bobcat trapper used leghold traps and Jack Russells to eliminate feral cat colonies on certain islands off the coast of  Baja California. And in islands plagued by rats, a poison called brodifacoum proved to be particularly lethal.

Stolzenburg writes about the tactics used to kill these invasive species.

And he does include the suffering.

Brodifacoum works as an anticoagulant, and the rat dies from internal bleeding over a period of about week. The rat is in a lot of pain while it dies.

He also includes a discussion of what happened when this poison was used on an island in the Aleutians that English-speakers have always called “Rat Island.”   Tons brodifacoum-laced bait were dumped onto the island just as a major storm began brewing, and the eradication team was forced to leave in a hurry after dropping its bait.

When they returned to the island a few months later, they found that there were no rats on the island anymore, but there are also many dead birds lying around, including 41 dead bald eagles. Toxicology reports showed that all of these birds had ingested the brodifacoum, and it was the cause of their demise.

These animals were collateral damage in this war against invasive species.

But to rid the island of rats would mean that the least auklets, which were now largely free of arctic fox predation,  could now breed up in larger numbers now that they weren’t being massacred by scores of rats. Stolzenburg describes the macabre way in which the rats kil the auklets. They find the little birds in their dens and then bite them through the skull, consuming the brains and eyes before taking the carcass to the rat’s cache, where as many as a hundred or so auklet bodies can be found stashed.

When the auklets and other sea birds return to their former numbers, the predators will have a lot more prey again. Gulls and eagles, the main species that were killed by the rat poison, will enjoy Halcyon days once that happens.

But the moral calculus that says it is justified to poison rats, trap cats, and shoot foxes is diametrically opposed to the animal rights ethos.

Stolzenburg describes animal rights activists becoming livid at those implementing the eradication programs. One individual even drops vitamin K supplements all over an island where brodifacoum baits have been dropped. Vitamin K is the antidote to the poison.

In another exchange, the director of the Aleutian Islands National Wildlife Refuge is contacted by the Sea Shepherd Conservation Society. The Sea Shepherds, which like to claim that they are a conservation organization, were angry that the arctic foxes were being killed.  They suggested to the director that it might be a better if they live-trapped the foxes and sent them to a sanctuary.

The director didn’t much like killing foxes. He got no thrill out of it.

So he decided to call the Sea Shepherds’ bluff. He said that if they’d come to the Aleutians, he’d be happy to have them live-trap the foxes.

The Sea Shepherds never responded to the offer.

As I read these accounts, I became more and more angry at the animal rights movement.

I know that is fashionable among some types to lump environmentalist and animal rights activists together.

But that’s a very shallow reading of what both sides stand for.

Animal rights says that all animals have rights as individuals and that it is morally wrong to kill them.

If one accepts that premise in its totality, then you’ve conceded biodiversity to the animals that we introduce all over the world.

If all animals as individuals have the right to exist, then you cannot implement the proper culling that is necessary to save certain island and island-dependent species from the depredations of invasive species or the habitat destruction that results from their arrival.

The two forces are diametrically opposed to each other.

One cannot be an animal rights activist of this sort and be a conservationist. You can pretend to be.

That’s all you can do.

Life on this planet is dependent upon variation. Within populations, variation is absolutely necessary for evolution. Within life itself, having many different lineages living on the same planet means that if one lineage becomes extinct, an organism from another lineage can evolve to take its place. For example, during the Middle Jurassic, there was a terrestrial crocodile called Junggarsuchus sloani. It was only three feet long, but it had long legs for running down prey. It was essentially a coyote from the crocodile lineage. In Australia and Tasmania, a coyote-like form evolved from carnivorous marsupials known as quolls. The thylacine, as we now call it, was replaced by the dingo on the Australian mainland, but if evolution hadn’t produced the dingo and man hadn’t introduced it, Australia would have become devoid of large predator if the thylacine had gone extinct on its own.

On New Zealand, crickets evolved to fit the niche of moles. A wren evolved to fit the mouse’s niche.  And there was a family of ratites– best known as the moas–that evolved to fit the niche of our ungluates.

If we don’t have biodiversity, life cannot readily deal with extinction. It will be harder for lineages to evolve to fit niches that are opened up by extinction– because the lineages won’t be around anymore.

This is what the animal rights people are conceding. They may be saving individual animals, but they aren’t saving biodiversity.

They’ve turned their backs on it.

Stolzenburg writes about the war against invasive species, but he alludes to one that is much deeper.

It’s the war that exists between the modern conservation movement and the animal rights movement.

Only a superficial understanding of what these two forces stand for sees them as being allies.

Deep down, they are not.  They are bitter foes.

Stolzenburg does an excellent job of exposing this great cleavage.



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I opened up the local online daily newspaper this headline to see this headline: WILL PUBLIC WATER COME TO CALHOUN WITH A GARLIC MUSTARD CHASER?

This particular water line extension has been very contentious. In fact, the money appropriated for it was ear-marked seven or eight years ago. In a very rural part of West Virginia, access to clean and reliable sources of water is a major concern. People have put in long hours on this water extension, and it is very important for this community.

Garlic mustard is a pain. Its full effect hasn’t hit this part of West Virginia yet, but it could be very damaging to our forest ecosystem. The plant is referred to in British parlance as “Jack-by-the-hedge.”

It is an innocuous plant, but its real problem is what it does to the soil chemistry:

Garlic mustard roots put out chemicals that change the soil that have now been proven to kill soil organisms responsible for the germination of yellow poplar, sugar and red maple, white ash and cherry seedlings.

There is also a large and growing list of native flowers and herbaceous plants that are killed by the changes in soil chemistry caused by garlic mustard.

For healthy soil, garlic mustard is the vegetative equivalent of AIDS.

For those of you who are not aware. Calhoun County, West Virginia, is over 90 percent forested. Its timber resources are a major source of wealth and tax revenue.  Healthy forests are key to having anything resembling a healthy economy.

To  make matters worse, it very easily colonizes densely forested land and then can spread very quickly:

Unlike other invasive plants such as Japanese stiltgrass, multiflora rose or autumn olive that move into and become established in disturbed areas like pastures, gullies and roadsides, garlic mustard readily spreads from ditches and roadsides into high quality forests where no soil disturbance has taken place.

A single plant can produce nearly 10,000 seeds and with over 250,000 seeds per pound, garlic mustard seed is extremely small. Each of the two inch long spikes on these garlic mustard plants can hold up to 100 seeds.

A golf ball sized clod of mud can hold hundreds of seeds.

In addition to causing long term damage to soil fertility and woodland productivity, garlic mustard produces seed that will stay viable in the soil for years as a “seed bank”.

The company that has been contracted to put in the water line currently has its equipment in an area where there are large stands of garlic mustard.  The potential risks from spreading garlic mustard could be prevented if the company simply washed its equipment before moving it in.

However, it is under no legal requirement to do so, and it probably won’t.

I do believe that these improvements are necessary to increase the standard of living to people living in this area. It’s just that the risk that garlic mustard poses must be considered in that calculus. It would be simple to mitigate these problems, but it would cost some money.

And, of course, garlic mustard is likely to get here on its own.

But maybe it could be delayed a bit.

I don’t know.

However, I will say that whenever I am out, the multiflora rose, the autumn olive, and the stilt grass have just about taken over the whole understory. That’s great for rabbits and certain songbirds, such as towhees.

Although West Virginia’s state tourism slogan is “Wild and Wonderful,” it is really quite domesticated place.  European man domesticated this garden a long time ago.  The forests that exist here are not the same ones that were here in the late eighteenth century. Very little of the original “forest primeval” still exists here. Most of what is now forest was pasture as recently as forty years ago.

I can’t imagine this countryside without acres and acres of dense forest. Let’s hope that the effects of garlic mustard on our landscape is as minimal as possible, because I don’t think we’re going to be able to stop it.

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