“My heart is broken in the face of the stupidity of my species.” Joni Mitchell 1 Native species are those that normally live and thrive in a particular community. They occupy specific habitats and have specific niches in their native environment. They have natural predators that help to keep their populations in check. Species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem by humans. Can cause significant ecosystem damage, due to having no natural predators in their new ecosystem Some Harmful Nonnative Species in the United States Fig. 9-11, p. 200 Deliberately Introduced Species Purple loosestrife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Marine toad (Giant Water hyacinth toad) Japanese beetle Hydrilla European wild boar (Feral pig) Fig. 9-11a, p. 200 Accidentally Introduced Species Sea lamprey (attached to lake trout) Argentina fire ant Brown tree snake Eurasian ruffe Common pigeon (Rock dove) Formosan termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Fig. 9-11b, p. 200 7 In 1957, attempts were made in Brazil to cross African honeybees with native honeybees in order to produce an overly aggressive bee – hoping this would increase honey production Several African honeybees escaped Eventually, the native honeybees were displaced through competitive exclusion and migrated northward at a rate of 200 miles per year. The bees’ Northward migratory rate is slowing down due to climate (frost). Will global warming allow their migration to move northward over time? Problems: They are so aggressive, they not only out-compete native bee populations, but pose great health threats to humans. 10 In the late 1930’s , red fire ants were introduced by accident in Alabama The ants were in shiploads of lumber and cargo that were imported from South America Interspecific competition (for resources) reduced native ant species by 90%! Fire ants are very aggressive and through direct combat, reduced native species. Since there are no natural predators, they produced more colonies than native ants and increased their population density significantly in the South. Interference Competition – fire ants consumed food and invaded habitat of native ant species (competitive exclusion principle – 2 species competing for the same resources cannot coexist sustainably). Fire ants release sulfuric acid when they bite and can kill deer fawns, lizards, birds, livestock, pets, and human babies. Fire ants have invaded trucks and caused roadside accidents when drivers have been attacked. Fire ants chew through underground cables and disrupt electric and phone services, and have started electrical fires in the South. Fire ants are pesticide resistant (Directional Natural Selection of r-strategists) In an attempt to control the fire ants, the USDA (US Department of Agriculture) introduced a non-native parasitic fly that deposits eggs on the fire ants. When the larvae develop, they eat the heads of the fire ant. ANARCHY! (Degrees Celsius) In the 1950’s, the Brown Tree Snake arrived in Guam in the wheel wells of airplanes from Australia One of the snake’s staple diets is birds. Eventually, the snake drove 85% of native forest birds to extinction. These snakes are highly aggressive, nocturnal predators. There are no natural predators of the Brown Tree Snake in Guam. These voracious eaters even consume domestic animals, and even small human babies! 1930’s - imported from Japan and planted in the southeastern USA to help combat soil erosion following the Dust Bowl. 1940’s – US Soil Conservation Service (federal agency) paid farmers subsidies to grow kudzu vine. Problems: No natural predators, very prolific reproduction. Presently, it costs the US government $500 million/year to eradicate! Possible Commercial Uses: Chemicals produced in the vine are used in Japan to combat diseases. USA found chemicals in vine may reduce alcoholic cravings. May be a source for paper products! Kudzu Taking Over an Abandoned House in Mississippi, U.S. Fig. 9-12, p. 201 In 1869, a French naturalist imported gypsy moths to Boston in an attempt to breed them with silkworms. Gypsy moth caterpillars escaped during the experiment. These moths eat the foliage of many hardwood trees, especially oaks and cherries. They continued to “hitch hike” rides via cargo into the USA. The current gypsy moth population can eat all of the leaves on 13 million acres of trees in 1 growing season! The beetle is native to China. In 1996, the beetle was found in New York City and Amityville, Long Island. They were believed to have arrived in the US from cargo pallets imported from China. Target trees: Norway, sugar, silver, and red maple. Will also feed on horse chestnut, poplar, willow, elm, mulberry, and black locust. Eradication method: Must cut down, chip, and burn the trees. New Method: in Central Park, New York City - the Parks Department injects “birth control” via hypodermic needles into the base of hardwood trees so that when beetle females feed on the trees, will become sterile This has significantly reduced the population in Central Park Problem: Costs a lot of $ and requires many employees to administer and monitor populations. Presently, the New York City Parks department exists on a shoe-string budget! Common Reed Phragmite s australis “ By reducing and degrading life’s support systems (Earth Natural Capital), we could make our own species more vulnerable to extinction, or at least to a massive population crash”. If we are the most “intelligent” species on Earth, why can’t we follow the simple laws of nature? Education Participate in local groups to conserve the biological integrity of ecosystems Promote local economic growth while thinking globally Refuse, Reduce, Reuse, Recycle Shop locally, think globally (be an educated consumer) GET INVOLVED AND TELL A FRIEND What Can You Do? Controlling Invasive Species Fig. 9-14, p. 203 34