Wednesday, March 28, 2007

Rabbits, toads, nutria and other ideas gone horribly wrong

Next time anyone considers smuggling some non-native critter into another state or country, hopefully that person will think twice about the consequences.

Often agriculture has ended up being negatively impacted by what can go wrong when these pets, game targets or science experiments run wild.

Check out ponds or waterways in Oregon, and chances are you’ll soon spot a familiar sight: nutria swimming among the ducks, walking on the muddy banks, or off searching a nearby field for a tasty treat.

If you’re not from the West, the first time you see it, you wonder what is it: beaver? Muskrat? Otter? For those who know it well, the nutria is described in one word: pest.

According to, nutria means otter in Spanish, and when it first was brought here from South America in the 1930s, people thought it would be a good thing for the state and the fur industry.

According to Oregon’s Department of Fish and Wildlife, “Many hopeful investors started small captive colonies in many locations in the United States, Canada, and many European countries. Many of these farms, however, did not succeed and the animals either escaped or were intentionally released to the wild, which resulted in the wild populations present today. Wild nutria were first reported in Oregon during the 1930s.”

Again, for those of you not in the West, here’s what it looks like, according to ODFW: “A nutria is smaller than a beaver but larger than a muskrat; unlike beavers or muskrats, however, it has a round, slightly haired tail. Nutria have large incisors that are yellow to orange-red on the outer surface. The dense grayish underfur is overlaid by long, glossy guard hairs that vary in color from dark brown to yellowish brown. The guard hairs are long and coarse on the back and finer on the side and the belly. The forelegs are small compared with its body size. The forepaws have five toes; four are clawed and the fifth is reduced in size. The claws are used to groom and to excavate roots, rhizomes, and burrows, and are used in feeding. The hind foot consists of four webbed, strongly clawed toes and one unwebbed toe. The hind legs are large compared with the forelegs; consequently, when moving on land, the nutria's front end is lower than the back end and it appears hunched.

“Nutria are approximately 24 inches long. Their round tail is from 13 to 16 inches long. Males are slightly larger than females; the average weight for a male is about 12-20 pounds, and average weight for a female is approximately 10 to 18 pounds. The ears are small and the eyes are set high on the head.”

Perhaps one of the most important things to note about nutria is this: “Nutria appear to breed throughout the year. Females sometimes give birth to their first litter when they themselves are only 8 or 9 months old. Each adult female produces two or three litters a year. The number of young per litter ranges from 2 to 11 and averages about 5.”

Not to forget: “Nutria are especially fond of alfalfa, clover, root crops, and garden produce (cabbage, carrots, sweet potatoes, etc).”

The department goes on: “Burrows can weaken roadbeds, stream banks, dams, and dikes, which may collapse when the soil is saturated by rain or high water. Rain action can wash out and enlarge collapsed burrows and compounds the damage.

“Nutria depredation on crops is also well documented. Crops that have been damaged include corn, sugar and table beets, alfalfa, wheat, barley, oats, various melons, and a variety of vegetables from home gardens and truck farms. Nutria girdle fruit, nut, deciduous and coniferous forest trees, and ornamental shrubs. They dig up lawns when feeding on the tender roots and shoots of sod grasses.

“At high densities and under certain adverse environmental conditions, foraging nutria can also significantly impact natural plant communities.”

Suddenly those fur-bearing animals don’t seem so lovable anymore. Actually, they’re sort of cute from a distance, but get close to one and as soon as they flash their yellow teeth, the cuteness disappears. Okay, so they are still cuter than opossums…

Lane County in Oregon is one of the places that has had enough of nutria.

According to an Associated Press story, these 20-pound nutria have been bothering people in Eugene and have become nasty.

“They're huge, and they look like a beaver with a rat tail,” resident Jim Hayes was reported as telling the media. “Not only that, but if you corner them, they can get nasty. They rear up on their hind legs and hiss.”

Some areas in Eugene have contemplated even putting in special fences to try to keep the nutria away, but these fences can be expensive and not an option for a lot of people fighting nutria.

And, of course, while the nutria might be stopped from burrowing underneath, the opossums might still find a way to climb into yards.

What to do if that opossum is in the yard? According to ODFW, ( be prepared: “When threatened, the opossum may bare its teeth, growl, hiss, bite, screech, and exude a smelly, greenish fluid from its anal glands. If these defenses are not successful, the opossum may play dead.”

Fortunately, most people in Oregon already find these critters in the latter state — only very dead — and usually quite flat, because often they’re roadkill.

Again, these animals were introduced here, carried from the Southern states by people who probably didn’t think they would become a problem someday. They were just supposed to be something for them to hunt, like they did in the good ol’ South.

These are just two examples of animals that are brought into a new place and there are dire consequences later. People don’t always consider what will happen: how fast do they reproduce? What special needs do they have? Will their diets lead to damage to agricultural crops in the area? How controllable are they? What natural predators are there? Do they spread diseases, cause damage to buildings, maybe harbor secret ambitions to dominate the world someday?

Which brings us to the topic of European rabbits and what they did to Australia.

Wild rabbits are more than just a nuisance there: it’s estimated that each year it costs $600 million in control costs and production losses. First introduced in the late 1700s, most of the problem appears to have originated in 1859 when rabbits were brought in and released as a target for hunting.

Obviously, killing rabbits isn’t as easy as the hunter thought. They began so spread rapidly in the country: soon millions of them were killing off native plants, and competing with livestock for food. Ten rabbits will eat as much grass as one head of sheep.

The Australians have tried everything from a rabbit fence 1,833 kilometers long to trying to introduce viruses to kill the rabbits. Each time there is some success with the viruses — in the 1950s, the virus successfully killed off 99 percent of the infected rabbits — but the population continued to jump back again.

Talk about your hare-raising situation.

In 1990, a cattle rancher in Australia was questioned what it was like when rabbits were at their worst when they attacked his farm. The rancher paused, then lifted his arm towards the horizon. He described what it was like to watch what seemed like a cloud of white slowly move towards him over the hills and through the valleys. He said the rabbits were unstoppable and ate almost edible everything in their path. He reckoned that was what locusts were like in other parts of the world.

As researchers continue to hop to conclusions on how to battle the curse of the rabbits in some parts of Australia, another part of Australia is fighting yet another problem that someone brought into the country.

After the problem with rabbits, surely people should have become more wary of bringing non-native wildlife into Australia.

However, a recent Reuters story said that in 1935 cane toads were brought to Australia from Hawaii to battle native cane beetles. Not only did the toads fail to do that, but they also increased to being 200 million toads.

Probably somewhere out there are the skeptics who first heard about and protested shipping toads into the county and they all exclaimed: “Toad you so!”

So how big is the toad problem?

According to the Reuters story, someone has captured a cane toad the size of a small dog: 8 inches long and just under 2 pounds, about twice the normal size of those toads.

When not scaring people, these poisonous toads have “ led to dramatic declines in populations of native snakes, goanna lizards and quolls, which are cat-sized marsupials,” said Reuters.

So where does this all leave us?

We probably will never truly learn our lesson, as long as there is international travel and people ignorant or stubborn enough to carry creatures from one place to another, for whatever the reason.

And never underestimate how determined people can be.

Last week, according to AP, guards at the Gaza-Egypt border stopped a woman who had three 20-inch long baby crocodiles strapped to her waist under her robe. Apparently, she was part of a smuggling ring that valued each crocodile as potential to earn $500.

The story explained that when the woman was searched, “At first there was a lot of screaming, but a spokeswoman for the European observers who run the crossing says people actually admired the woman who was able to ‘tie crocodiles to her body.’”

The lesson learned: the smuggling world is not all it’s croc’ed up to be.

Now, how cute are these quolls, can they scare off the nutria, and how can they be smuggled here?

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