Download PART III

INVASIVE or NON-NATIVE
SPECIES
A MODERN-DAY CAUSE OF
COMPETITION AND
EXTINCTION
What Are Native Species?
• 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.
What Are Invasive or Non-Native
Species?
• Species that
migrate into an
ecosystem or are
deliberately or
accidentally
introduced into an
ecosystem by
humans.
Africanized Honeybee (Killer Bees)
• 1957 African honey be crossed with native
honey bee to produce an overly aggressive
bee in Brazil which escaped.
• Displaced the native honeybee through
competitive exclusion and migrated
northward at a rate of 200 miles per year.
• Northward migratory rate 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.
Geographic Distribution of
Africanized Honey Bees in USA
Fire Ants
• Late 1930’s introduced by accident in Alabama
in shiploads of lumber and cargo.
• Interspecific competition 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
south.
Fire Ants
• Interference Competition – fire ants consumed
food and invaded habitat of native ant species
(competitive exclusion principle).
• They release sulfuric acid when they bite and
can kill deer fawn, lizards, birds, livestock, pets,
and human babies.
• Fire ants have invaded trucks and caused
roadside accidents when drivers have been
attacked.
• Chew through underground cables and disrupt
electric and phone service and have started
electrical fires in the south.
Fire Ants
• They are pesticide resistant
(Directional Natural Selection
of r-strategists)
• USDA (US Department of
Agriculture) has 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. CHAOS!
$$$$$$$$
Fire Ant Distribution in the USA
(Degrees Celsius)
Brown Tree Snake
• 1950’s arrived in Guam
in wheel wells of
airplanes
• Drove 85% of native
forest birds to extinction.
• Highly aggressive
nocturnal snake.
• No natural predators.
• Eats domestic animals,
even small human
babies.
Native Range of Brown tree Snake
Distribution of Brown Tree Snake in
USA
Kudzu Vine
• 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 a subsidy to grow kudzu vine.
• Problems: No natural predators, very prolific
reproduction. Costs USA 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 Vine Distribution in USA
Invasive Species on Long Island
• Gypsy Moth – 1869, a French
naturalist imported gypsy
moths to Boston in an attempt
to breed them with silkworms.
• Gypsy moth caterpillars
escaped during the experiment.
• They eat the foliage of many
hardwood trees, especially
oaks and cherries.
• They continue 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!
Asian Longhorned beetle
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The beetle is native to China.
1996 Found in New York City and Amityville, Long Island.
Believed to have come over in cargo pallets from China.
Target trees: Norway, sugar, silver, and red maple.
Will also feed on horsechestnut, poplar, willow, elm, mulberry, and
black locust.
Eradication: Must cut down, chip, and burn the trees.
New Method: Central Park, New York City Parks Department injects
“birth control” via hypodermic needles into the base of hardwood
trees so that females will become sterile as they feed. This has
significantly reduced the population in Central Park
Problem: Cost lots of $ and requires many employees to administer
and monitor populations.
New York City Parks department exists on a shoe-string budget!
Asian Longhorned Beetle
Invasive Species in Green’s Creek
Watershed
Common
Reed
Phragmites
australis
Purple Loosestrife
Lythrum salicaria
Japanese Knotweed
Polygonum cuspidatum
Oriental Bittersweet
Celastrus orbiculatus
Garlic Mustard
Alliaria petiolata
Bamboo
What Is Our Future?
• “ By reducing and degrading life’s support
systems (Earth 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?
What Can You Do?
• 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