The Invaders

Axis Deer
Axis Deer
There are now more free-ranging axis deer in Texas than in all of their native India. In some counties, axis deer outnumber whitetails. The reason for this massive population? Texas has good land and no tigers - the axis deer's natural predator.
Photo: Sumeet.moghe
Blackbuck antelope
Blackbuck antelope
Another native of India with high numbers in Texas. Part of the reason for their success stems from the fact that decades ago ranchers looking to expand their hunting operations purchased blackbucks after being told they couldn't jump barbed wire fences. Guess what? They can. Photo: pranav yaddanapudi
pranav yaddanapudi
Nilgai
Nilgai
Yet another native of India, nilgai are the second largest antelope in the world. They can be found along the Texas Gulf Coast in free-ranging numbers estimated at over 30,000. Although hunts for nilgai are generally pricey - two grand and up - it's the best big game hunt this side of Africa. Photo: Andrew C
http://en.wikipedia.org/wiki/File:Boselaphus_tragocamelus1.jpg
Fallow Deer
Fallow Deer
Fallow deer in the United States date back to the 1700's. George Washington had fallow deer on his property until a falling cherry tree crushed the entire herd. Ok, I can not tell a lie. I fabricated the cherry tree part. But George did own a few. Photo: Johann-Nikolaus Andreae
[Johann-Nikolaus Andreae](http://en.wikipedia.org/wiki/File:Fallow_deer_in_field.jpg
Feral Cats
Feral Cats
Feral cats can be found anywhere house cats can be found - which is right outside my bedroom window at two in the morning. These nasty kitties have unleashed untold destruction on birds such as dove and quail. Many landowners shoot them on sight. Photo: Commons
Commons
Feral Dogs
Feral Dogs
Who let the dogs out? Who? Who? I don't know but they shouldn't have. Feral dogs are becoming a bigger and bigger problem in the U.S. When left unchecked they kill deer and other game animals. They also carry disease and, on occasion, attack humans. Think predator calling for dogs is farfetched? Just wait a decade or so. Photo: Kurt Sagmeister
Kurt Sagmeister
Monk Parakeets
Monk Parakeets
These nasty little once-upon-a-time pets displace both song and game birds. They're loud and obnoxious and I can't wait to pop one with a pellet gun down at my mother-in-law's near Corpus Christi as soon as she gives me the ok to put a ground blind up near her bird feeder. Come on Sandra. Please. Photo: Kip Kee Yap
Kip Kee Yap
Sucker Fish
Sucker Fish
Sucker fish do just that - suck. Like carp they suck up fish eggs and just about anything else they can get in their nasty little armored mouths. They apparently can't be caught on hook and line and aren't going anywhere other than across the U.S. soon. It's estimated that there are over 100,000 in Texas alone.
Wikimedia Commons
Snakehead
Snakehead
Coming to a body of water near you - soon! Already found in Maryland, Pennsylvania, North Carolina and possibly Florida, these ferocious predators are estimated to spread across the Southern U.S. in the years to come. I hate to think of what could happen if I encounter one of these terrorist fish while I'm skinny dipping.
Wikimedia
Tilapia
Tilapia
This invasive actually tastes pretty darn good which, I'm sure, is why someone put them into U.S. waters in the first place. Problem is that they breed like rabbits and displace native species such as bass. Photo: Niall Crotty
Niall Crotty
Carp
Carp
Unlike tilapia, carp taste nasty. No. No, don't email me that they taste good when prepared correctly. They don't. They're nasty.
Wikimedia Commons
Monkeys
Monkeys
Free ranging populations now exist in Florida and Texas. Where they'll spread next is anyone's guess but given the fact that some monkeys know sign language and others have flown into space I'm very worried.
dillif
Pythons
Pythons
What is now the scourge of the Everglades is expected to spread across the southern U.S. in the coming decade. Warming temperatures won't help matters. That's just what I want to encounter on my way to the deer blind - a 12-foot constrictor. Photo: Dawson
Dawson
Iguanas
Iguanas
Iguanas can be found in parts of Florida and, like pythons, are expected to move across the south. The fact that they taste like chicken is of no consolation to me.
americanxplorer13
Cobra
Cobra
I know a guy who catches pythons in Florida who caught two cobras just outside the Everglades last year. He swears there are more out there. I have no reason to doubt him … despite what he says about Elvis.
kamalnv
Feral hog
Feral Hog
The king daddy of invasive species. As the saying goes, "There are two kinds of states, those that have feral hogs and those that don't have them yet."
Makro Freak
Swan
Swan
Mute swans are beautiful but given their size - four feet tall on average - and their extreme aggressiveness, most predators give them plenty of room. This has led to out of control numbers of giant birds in many states. Maryland alone has an estimated 4,000 mute swans within its fresh, brackish, and salt waters where they destroy nests of other birds and habitat for crabs and fish. Because of this I predict Remington will be coming out with 12-gauge swan load in the years to come. Photo: Marek Szczepanek
Marek Szczepanek
Rock pigeon
Rock Pigeon
Rock pigeons are nothing more than flying rats. They crowd parks, bridges and seem to attract homeless people. Photo: J.M. Garg
J.M. Garg
Mongoose
Mongoose
Mongoose - mongeese? - are vile little rats totally unlike the Rikki-Tikki-Tavi of the Chuck Jones cartoon. They destroy colonies of birds, kill native snakes, and burrow into the ground. I mostly hate them because they live in Hawaii and I don't. Photo: unununium272
unununium272
Nutria
Nutria
A rat is a rat is a rat. And I ate one of these rats in college and had a stomach ache for three days straight.
Petar Milosevic
feral goat
Feral Goat
Feral goats and sheep are becoming a bigger and bigger problem in the U.S. In some parts of Texas and Hawaii they have all but destroyed the landscape for other animals. Not only that, but feral goats are always bugging me about crossing my bridge.
Peripitus
aoudad
Aoudad
Sometimes referred to as "land carp" because of their ability to spread quickly and dominant an area, aoudad have successfully pushed mule deer and big horn sheep from their native habitat in parts of Texas and New Mexico.
Rei
cymothoid isopod.
THE SPACE INVADERS
Not all non-native species are considered invasive. To earn that label, you have to be a real rabble-rouser. A species becomes invasive only if it replaces an existing lifeform and disrupts an ecosystem. Take the gruesome cymothoid isopod.
Wikimedia Commons
crab
Invaders to our coastline come in all forms--plants, animals, parasites--but they all have one thing in common: By their very presence, they alter the balance of ecosystems that produce some of our most sought-after commercial and recreational species of fish and underwater food. Although estimates vary as to the economic impact of these unwelcome newcomers, some put the cost to businesses as high as $100 billion a year. The mitten crab--which like any good villain has an a.k.a., in this case either the big binding crab and the Shangahi hairy crab--is at the top of the list of invasive species that are an almost constant threat to what we have come to think of as the natural population of our waters.Wikimedia commons
Seaweed
A recent article in the Boston Globe said that scientists know of about 50 non-native species off New England's coast that they probably can't do anything about, including a European seaweed known as "dead man's finger" that arrived in the 1960s and is now being tied to the destruction of cod and sea urchin habitat. That species, codium fragile, takes root in eel grass beds, which are nurseries for juvenile fish and lobsters. Because if a piece breaks off it can regenerate, the codium is out-competing the eel grass and kelp and taking over. So what's the big deal? Seaweed is seaweed, right. No. Because the codium branches are round and spongy and about the thickness of an adult human finger, they inhibit the movement of fish, lobsters and sea urchins and halt their reproductive cycles. That in turn hurts other larger fish that eat the immature ones. No food, no fish. The dead man's finger could be pointing towards disaster.Wikimedia Commons
tongbiter parasite
Known by many as a "tongue biter," this parasite hooks its legs into the tongue of a fish, particularly bluefish and striped bass in the mid-Atlantic states, and eventually the tongue falls out.Wikimedia Commons
parasite
Scientists cannot pinpoint where this parasite originated, but they have not yet found a connection between the tongue-replacing tenants and a decrease in the lifespan of fish. So even though it doesn't get any more invasive that a tongue biter, that doesn't necessarily make it an invasive species.Wikimedia Commons
Asian Crab
The Asian shore crab, first spotted along the New Jersey coast in 1988, quickly became more populous than its green crab cousins in many areas of Long Island and New Jersey and now are the dominant crab found on rocky shorelines. Because of their ability to withstand not only tropical waters but sub-freezing conditions, their breadth reaches from Cuba to Maine. The Asian crab is a more aggressive feeder that the green, so it can bully its way into pre-existing turf, often feeding on the larva of its competitors which include other crabs and even lobsters. Pesticides and global warming have been blamed for the lobster die-off in Long Island Sound, but researchers are quick to point out the corresponding timeline between the ascent of the Asian crab and the descent of the lobster.Wikimedia Commons
sea squirt
Another seemingly innocuous creature that can cause eco-chaos is the sea squirt. These animals that look like plants cling to boats or pilings and suck water in one end and out the other. When they latch onto moorings they create a thick crust that isn't only an aesthetic blight, but because they release a noxious substance as a byproduct of their metabolism, prevents other creatures from mounting to the same form and also discourage predators. It is also an economic nuisance to aquaculture structures used in the farming of oysters and other shellfish. Yet the scariest occurrence of the sea squirts, or tunicates, may by at Georges Bank, where the animal has been seen to reach very high densities, covering large areas of ocean floor like an impenetrable pancake batter and choking it off.Wikimedia Commons
Lion fish
By 2002 the first Atlantic lionfish was captured and today they can be spotted all along the southeast coast of the United States and, depending largely on water temperatures, as far north as New York. Commercial and recreational anglers have been known to hook them, too. Although scientists have been unable to prove that lionfish are reproducing, their quickly-growing numbers strongly suggest that this is the first time that a western Pacific fish has populated the waters of the U.S. Atlantic coast. Lionfish, a popular specimen for aquarium enthusiasts (who are believed to have introduced them into their new waters by dumping), are easily identified by their black and white stripes and their long, dangerous spikes that contain a venom that can kill prey, discourage attackers, and cause severe pain in humans. They sport a voracious appetite that belies their dainty, delicate look, and they feed mostly on small shrimp and larger fishes, including the young of commercially important species such as snapper and grouper that are bred in the same reefs lionfish are starting to dominate. Because there was very little research on the hard-bottom habitats where lionfish have been reported in the Atlantic, it is difficult to determine what the ecological impact of lionfish is on their new ecosystem. "As a result, there is nothing to compare the present situation to," Whitfield wrote. "It would have been nice to be able to do a 'before and after' comparison, but it is not possible." About the only thing that can slow the lionfish spread is temperature. Because they are a tropical fish, they require certain warmths that not all waters provide. But scientists believe that in the warmer waters of the Atlantic, lionfish could soon have a population density that approaches or even exceeds their numbers in their native Pacific.Wikimedia Commons

Invasive and feral species are changing the United States' ecosystem at an alarming rate. Here's a look at what you might be hunting and fishing for a decade from now.