When Animals Invade

WHEN ANIMALS FOREIGN AGENTS-OF THE WINGED, FINNED, AND FOUR-LEGGED KIND-HAVE BEEN QUIETLY INVADING THE U.S. FOR DECADES. MEET TWELVE INVASIVE INVADE SPECIES EATING AMERICA ALIVE. ZEBRA MUSSEL Dreissena polymorpha Not much bigger than a quarter at adulthood, the zebra mussel is making a huge impact. It made its way from the lakes of southern Russia to U.S. waters in the 1980s via ballast water (which large ships carry for stability, and occasionally discharge at ports of call). The zebra mussel attaches to surfaces using "byssal threads," helping it out-compete native species...and clog underwater pipes. The zebra mussel is also blamed for spreading avian botulism that kills wild birds. BY JULIE ROSSMAN AND ROXANNE PALMER ASIAN TIGER MOSQUITO Aedes albopictus Though native to the tropics of Asia, the Asian tiger mosquito has developed the ability, on encountering colder climates, to hibernate throughout the winter. In the continental U.S., the mosquitoes were first noticed in a shipment of used tires in 1985. An aggressive biter of humans in the daytime, the Asian tiger mosquito also carries numerous pathogens, including West Nile Virus and dengue fever. Native to Eurasia (specifically southern Russian lakes) MUTE SWAN Cygnus olor Elegant and beautiful at a distance, mute swans were imported from Europe by posh Americans in the late 1800s to ornament their private estates, but soon you guessed it-escaped into the wild. Mute swans gobble up native wild aquatic grasses (up to 8 pounds a day), and are very aggressive, driving native birds away from nesting sites and feeding areas. Recently, New York state weighed a plan to kill mute swans, but a public backlash forced the Empire State to consider nonlethal methods of control. Native to Asia Native to Europe ASIAN CARP Ctenopharyngodon idella & other species In the 1960s, several species of East Asian carp were imported to clean phytoplankton from retention ponds in wastewater treatment and aquaculture facilities. The carp, which can grow to five-foot lengths and tolerate temperature extremes, have invaded waterways throughout the U.S., and threaten to invade the Great Lakes. Asian carp steal freshwater mussels and snails, plankton, and fish larva from native fish, and, leaping high out of the water, pose a physical risk to boaters. "We're calling it an imminent threat," says Tammy Newcomb, a researcher with the Michigan Department of Natural Resources. "They're doing well in river systems, but we expect them to do even better in lakes." EUROPEAN STARLING Sturnus vulgaris-- In 1890, as part of a plan to introduce all the birds named in Shakespeare's plays eccentric drug maker Eugene Schieffelin released 80 European starlings (from Henry V, Part I) in NYC's Central Park. The lucky birds, which eat practically anything, have since winged and eaten their way across the nation, attacking crops-particularly grapes, olives, cherries and grains-and competing with native woodpeckers, swallows and bluebirds. They carry diseases transmissible to humans and livestock; large flocks of starlings near airports also pose a significant "bird strike" risk to planes. America, Native to East Asia (including waterways of China, eastern Russia, northern Vietnam) Native to Europe & Central Asia ASIAN LONG- HORNED BEETLE Anoplophora glabripennis CRAZY ANT Infested wooden packing materials from Chinese imports in the late 1980s brought us the Asian long-horned beetle. The wood-loving pest-which can also spread via transport of contaminated firewood-has proved tough to eradicate: Developing beetles spend most of the year holed up inside trees, out of reach of insecticides, leaving destroying infested trees the only reliable solution for beating back infestations. The beetle threatens Nylanderia fulva Also known as the tawny crazy ant or the raspberry crazy ant, N. fulvia, believed to be a South American pest that migrated north via a commercial ship, has made life miserable for Texans since the early 2000s. It irritates wildlife, especially nesting songbirds; it caus- es grasslands to dry out by aggravating plant pests (the ants feed on the "dew" these other insects create). Crazy ants don't sting, but their bite causes sharp pain in humans, and they can swarm and asphyxiate small livestock, or cause short-circuits in electrical equipment: Even NASA had to call in exterminators. native hardwood trees including maple, willow, birch, sycamore, and horse chestnut. Native to Asia Native to South America (possibly) KILLER BEE LIONFISH Apis mellifera hybrid Pterois volitans This venomous fish, native to the Western Pacific Ocean, made it to the Atlantic coast in the 1980s, perhaps after escaping or being released from aquariums and private owners, or after its larva drifted across on ocean currents. In addition to crowding out and eating native species, the lionfish is believed to contribute to the destruction of coral reefs in the Atlantic, indirectly, by eating all the herbivorous fish, leaving nothing to control the algae that then over- whelms a reef. Wildlife officials are hoping to control this invader by advocating eating it: Once the venomous spines are removed, the lionfish proves to have tasty, buttery flesh. In Brazil in the 1950s, biologist Warwick Kerr bred African and European honeybees to create an "Africanized" bee he hoped would fare better in Brazil's tropical environment. But a number of these adaptable bees escaped from Kerr's labs and spread north, reaching America in the '90s. The Africanized honeybee is smaller but more aggressive than its Euro-cousins, stinging and swarming more often, killing large animals (and, rarely, humans) they perceive as a threat. With a widę range of possible habitats, they displace hative honeybees and thereby disrupt agriculture. Native to the Western Pacific Ocean Native to Brazil CANE TOAD Rhinella marina TEGU LIZARD Tupinambis Cane toads can weigh more than 3 pounds, and males have a mating call that's been compared to a distant tractor. Native to South and Central America, Mexico, and parts of Texas, the toads were carried into other parts of the U.S. to control pests in sugar cane fields, starting in the 1930s. Bad idea: The toads have a voracious appetite, competing with-and even preying on-native frogs and toads. As a bonus, the toad's toxic skin can kill wildlife and pets. These South American lizards, with their black and white beaded skin, make the ideal exotic pets. But when they start reaching their full length-up to four feet they get a lot less cute. Florida officials have now found colonies of tegus, escaped or released, in three Florida counties in the past few years. "Tegus have become established in multiple areas in Florida because they reproduce quickly and eat a wide variety of food items, including small animals and eggs of many wildlife species," says Carli Segelson, Florida Fish and Wildlife Commission. NUTRIA Myocastor coypus This dog-size South American rodent, also known as the coypu, was brought to America in the late 1800s, first as an alternative to mink for furriers, and later to help control weeds. But the nutria destroys native plants and crops, and can damage marshes and wetlands. Some states encourage hunters to target nutria-Louisiana, for example, offers cash incentives for people that bring in nutria tails. Native to South & Central America, Mexico Native to South America World Science Festival Native to South America worldsciencefestival.com