National Park Service
Jan. 17, 2013 -- The invasion of Burmese pythons in Florida's wetlands poses an existential challenge to the state's native wildlife as these apex predators have been known to prey on everything from small animals like raccoons and opossums to larger ones like white-tail deer and even alligators.
How has the state faced the challenge of dealing with 150,000 non-native snake threatening its biodiversity? The answer is a good old-fashioned hunting contest, of course. Florida's "Python Challenge" has drawn some 800 snake hunters, according to a report by the Associated Press. Most of the snake hunters are amateurs, so they're given some instruction: "Drink water, wear sunscreen, don’t get bitten by anything and don’t shoot anyone."
Good advice. But can the state of Florida really shoot itself out of this mess?
State of Louisiana Department of Wildlife and Fisheries
Invasive species might be bad for the environment, but many of them are good enough to eat.
Tiger prawns in the Gulf, Asian carp in the Great Lakes and many other species have been put on the menu in their respective locales in an attempt to thin their numbers.
In fact, there are even books devoted to taking advantage of the potential of using invasive species as a potential food source.
Sometimes, nature will take care of a problem all on its own.
A study published in 2010 in the Journal of Arid Environments sought to document invasive bullfrog populations in the mountains of Mexico's Baja California. To their surprise, the invaders were actually put under severe pressure due to flash floods that occurred periodically in the region that they simply weren't adapted to cope with.
The bullfrogs happen to breed during the hurricane season, making them vulnerable to population swings. Native frogs, on the other hand, fared just fine circumstances they were adapted for.
Just as the environment can help push out an invasive species, so too can a well adapted native on rare occasions.
A University of Georgia study conducted in 2012 found that some native clearweed plants in the Peach State have evolved resistance to garlic mustard, an invasive plant first introduced 150 years ago to the United States from Europe.
The garlic mustard, a noxious plant that spreads rapidly, is evolving a counter-resistance, setting off a kind of chemical warfare among the native and invasive species.
David Pattermore/Princeton University
In some cases, the best policy for dealing with invasive species is just to leave them alone, particularly if they occupy a crucial ecological niche that they or other invasive plants and animals forced another species to vacate.
A study by Princeton researchers in 2011 found that invasive ship rats brought to New Zealand's North Island when Europeans first arrived devastated local populations of birds and bats. As pollinators, the native species were an important part of the ecosystem, but the ship rats have filled that role. As one of the researchers explained in a press release, "the killer stepped in to do the job of its victim."
Furthermore, efforts to eradicate the invader could come at a cost to native species.
Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database / USDA SCS
One common tactic for reducing populations of invasive species is simply to make their importing them from their native habitat illegal.
State fish and wildlife departments monitor the potential introduction of invasive plants and animals from outside their jurisdictions. Alligatorweed, for example, is an invasive aquatic plant that originated in South America and can not only endanger native species, but also put humans at risk by reducing water quality.
Unfortunately, that tactic doesn't seem to have its limitations. Florida, after all, eventually made it illegal to import Burmese pythons, but that hasn't stopped in the increasing numbers of these snakes in the Sunshine State.
One of the world’s most invasive species, the New Guinea flatworm, is on the move and has just invaded six new locations, including the continental U.S. — Florida — according to a new study.
The worm (Platydemus manokwari) is on the “100 worst invasive alien species” list, and is now newly located in New Caledonia, Singapore, the Solomon Islands, Puerto Rico and Florida, according to the study, which is published in PeerJ.
Although the worm lives on the ground, it is able to climb trees to follow and consume prey.
Jean-Lou Justine of the Sorbonne’s National Museum of Natural History and his international team of colleagues identified the dreaded worm at the various sites based on observations, DNA sequencing and other techniques.
Because the worm feasts heavily on native mollusks, threatening their populations, the researchers write that “the newly reported presence of the species in mainland U.S. in Florida should be considered a potential major threat to the whole U.S. and even the Americas.”
Until now, infested territories were mostly islands, and the spread of the species from island to island is limited. In expansive areas that are not islands, the world is this flatworm’s proverbial oyster, ready for takeover.
As its name suggests, the worm is indeed very flat. Its back is a black olive color with a clear central stripe, and it has a pale white belly. Its head is elongated with two prominent black eyes. Its mouth is actually in the middle of its belly.
The molluscs that it eats are local snails, which might sound like a good idea if you’re trying to rid your garden of these slimy creatures, but native snails are critical to their ecosystems. They eat very low on the food chain, often consuming rotting vegetation and fungi.
Snails also serve as food for all sorts of local wildlife, including certain insects, lizards, snakes, salamanders, birds and mammals. Some fireflies, in particular, love to munch on snails.
Such animals would be deprived of their food source if the invasive flatworm gets its way. As for how the worm travels so far and wide, in addition to its own journeys, it “can easily be passively spread mainly with infested plants, plant parts and soil,” Justine and his team write.
Eradication of the worms is challenging, given that other non-invasive species could be harmed in the process, so the scientists continue to study the worms, to better understand their biochemistry and life cycles.