AnnouncementsApril 4, 2011
Program in Ecology, Evolution, and Conservation Biology
Bradley Cosentino"Metapopulation dynamics and spatial genetics of the tiger
salamander”
Wednesday, March 16, 20114:00 P.M.
B102 CLSL Auditorium
Invasive Species
Lecture Objectives:
1. Be introduced to biological invasions
2. Know several examples of invasive species
3. Learn what you can do to stop the spread of invasive species
Python Explodes After Eating AlligatorOctober 5, 2005 MIAMI, (AP)
Alligators have clashed with nonnative pythons before in Everglades National Park. But when a 6-foot gator tangled with a 13-foot python recently, the result wasn’t pretty. The snake apparently tried to swallow the gator whole — and then exploded.
The gators have had to share their territory with a python population that has swelled over the past 20 years after owners dropped off pythons they no longer wanted in the Everglades. The Asian snakes have thrived in the wet, hot climate.
Percentage of threatened or endangered species in the U.S. imperiled by:
Why are species declining?
Disease - 3%
Overexploitation - 17%
Pollution - 24%
Invasive species - 49%
Habitat degradation and loss - 85%
Dave Wilcove et al. 1998 BioScience
Introduced (non-native, exotic) - species introduced deliberately or accidentally from somewhere else
Definitions:
Domestic/Feral (released pets, livestock and game animals) - can spread disease, compete with native species
Human commensal or subsidized (out of control natives) - native species that benefit from our land use (disturbance)
Invasive species - species that spread subsequent to establishment usually at some cost.
Transport of Invasive Species
Introduced deliberately:
•naturalization societies
•Shakespeare fans
•game animals
•domestic animals
•plants for agriculture
Accidental:
•ballasts of ships
•unprocessed wood
•fruit shipments
•by-pass natural barriers
•escapees (from zoos)
Snake Escape Makes Zoo SquirmMARCH 28, 2011
An Egyptian cobra was still on the loose at the Bronx Zoo Sunday after slithering out of its enclosure Friday afternoon.
Zoo keepers shut down the Reptile House "until further notice" to look for the venomous 20-inch snake. Officials said the cobra's reclusive nature meant it posed little danger to the public.
Ballast Tanks
Movement of/ increased exposure to exotic species includes pathogens!!
• Emerging Infectious Disease – never known before or absent for 20 years • Schistosomiasis, AIDS, SARS, etc.
“Forecast and control of epidemics in a globalized world.” Hufnagel et al. PNAS 2004
There are tens of thousands of introduced species in the USA
including: over 5000 plant species, 150 ant species
Why study biological invasions?
Unique opportunities for basic researchcommunity ecology
animal behaviorevolution
Consequencesthreaten biodiversity
costlywidespread
Estimated annual costs associated with non-native species:
Group costs (in millions)Plants (purple loosestrife, weeds) 34,000Mammals (feral pigs, rats) 37,000Birds (pigeons, starlings) 2,000Fishes 1,000Arthropods (ants, termites, other pests) 19,000Mollusks (zebra mussel, asian clam) 1,200Microbes (plant pathogens, animal disease) 41,000
All organisms over $136 billion per year
Source: Pimentel et al. 2000 BioScience
•First successful introduction was 60 European starlings released in Central Park, NY. in 1890, by fans of Shakespeare
European Starling
•slippery sidewalks
–competes with bluebirds, woodpeckers
Birds
European Starling
•The House Sparrow was introduced into Brooklyn, New York,
in 1851.
House Sparrow
•Competition from the House Sparrow for cavity nests can cause decline of some native species.
InsectsAfricanized Bees
• In 1956, African Honey Bees were imported into Brazil
•In 1957, 26 African queens escaped
•Reached US in 1990
•More aggressive than European Honey Bees, have killed 1,000 people
•Impact honey and pollination industries
Insects
• Crop pests– boll weevil, corn
borer
• Culex mosquitos– carry avian malaria
and pox– driven 20 Hawaiian
bird species extinct
Adult boll weevil
Insects
• Asian Long-horned Beetle– attacks and kills many
native trees
Found in Chicago in 1998
• Gypsy moth
•Introduced in 1860s
•Originally brought to the US for silk production
•now defoliates entire forests
Insects
The red imported fire ant
Insects
Why worry about introduced ants?• Ecological pests - ecosystem level effects
Reptiles and Amphibians
Cane toad – native to Central and South America
•milky secretions are highly toxic. Kill dogs, cats and small native animals
•Introduced world-wide to control insects
Monster cane toad found in AustraliaWed Mar 28, 2007 SYDNEY (Reuters) - A huge cane toad the size of a small dog has been captured in the Australian tropical city of Darwin, startling environmentalists who are fighting to stop the poisonous amphibians spread across the country.
"It's a monster toad," said Paul Cowdy from FrogWatch which captured the cane toad on Monday night. "We've never seen a cane toad this big," he said on Tuesday. "It's a male and normally females are bigger."
Mammals• Goats and pigs
– in Hawaii wiped out native plants
• Horses in Grand Canyon– causing erosion
• Game animals– “Texotics” “Texotics” Oryx
Photo: Dr Mike Hill
Mammals• Cats
– Outdoor cats and feral cats
– Recreational hunters
– Can cause declines in native small mammals, birds and lizards
PlantsKudzu
•kills other plants by smothering them under a solid blanket of leaves
•Introduced into the U.S. in 1876 at the Philadelphia Centennial Exposition
•promoted as a forage crop and an ornamental plant until 1953
PlantsGarlic mustard
Buckthorn•garlic mustard outcompetes native plants by monopolizing light, moisture, nutrients, soil and space.
•Not as good food for herbivores as many native species
•poses a severe threat to native plants and animals
Northern Snakehead(Channa argus)Found in Maryland in 2002
Giant snakehead (Channa micropeltes) found in Wisconsin in 2003
Fish
Laurentian Great Lakeswww1.ncdc.noaa.gov/pub/data/images/ great-lakes-ice-avhrr.gi
Superior
Mic
higa
n
Huron
Erie
Ontario
Mills et al. 1993
Over 140 exotic species
Many fish species were (and continue to be) released intentionally
Many other exotics have entered the lake accidentally:
Escape from captivity
Canals
Bait buckets, live wells and gear
Ballast water
Welland Canal
Begun in 1829
Niagara Falls was the major obstacle to an uninterrupted waterway
Sea Lamprey (Petromyzon marinus)
Invaded the Great Lakes after the opening of the Welland Canal
Devastated native fish stocks, especially lake trout
Other fish (>25 species)
Alewife (1873)(Alosa pseudoharengus)Canals
Coho salmon (1933)(Oncorhynchus kisutch)Deliberate release
Round goby (1990)(Neogobius melanostomus)Ballast water
Chinook salmon (1873)(Oncorhynchuys tshawytscha)Deliberate release
Asian Carp in the Great Lakes? This Means War!By Bryan Walsh Tuesday, Feb. 09, 2010
There are illegal immigrants on the loose in the Midwest. Originally hailing from Asia, they're about 3 ft. (90 cm) long and weigh up to 100 lb. (45 kg), and are known to resist capture. Once they establish residency, they can eat you out of house and home.
They're called Asian carp, and they emigrated to the lower reaches of the Mississippi River in the 1970s. Now they're knocking on the door of the Great Lakes, threatening to destroy one of the most valuable aquatic regions in the U.S., unless the often fractious Great Lakes states manage to pull together and keep them out. The situation is so serious that the White House convened an "Asian carp summit" on Monday to work out a defense plan.
Exotic mollusks (> 14 species)
Asiatic clam (1980)(Corbicula fluminea)Aquarium release
Quagga mussel (1990s)(Dreissena bugensis)Ballast water
ZEBRA MUSSEL — Dreissena polymorpha
Found in 1988 in Lake St. Clair (Lake between Huron and Erie, just off of Detroit, MI).
Likely came to North America in ballast water
Up to 70,000 individuals per m2
Also attaches to boat hulls, docks, locks, breakwaters and navigation aids, increasing maintenance costs and impeding waterborne transport.
One of the most expensive exotic species
Will biofoul and restrict the flow of water through intake pipes (drinking, cooling, processing and irrigating water)
How to prevent the spread of aquatic nuisance species?
Empty all water before leaving site
Never dump bait buckets!!
Before leaving site, inspect gear, boats and trailers for exotics
Let equipment dry for several days (does not work for species with resting eggs)
Rinse your boat and equipment with high pressure hot water, especially if moored for more than a day
How do we control invasive species?
• In urban and agricultural areas pesticide use still common
• Natural enemies - Biological Control
• Manage the landscape to minimize disturbance– Turn off the water; landscape with native
plants
Results of pesticide use
• Kills native competitors
• May select for resistance
• Health risks for people
The controversy over DDT
Biological Control:
The use of one species to control another.
Usually a specialist predator or parasite of an invasive species.
Needs to be species specific or could cause even worse problems.
Prevention
• Education is key• Research is still needed - generalities?• Monitoring programs - early detection• Prevent establishment - quarantine• Increased communication among agencies• Increase regulations
What can you do to stop the spread of exotics?
http://www.invasivespeciesinfo.gov/
•Why should we be concerned about, invasive species. How are they often introduced?•Be able to recognize common introduced species in the U.S. and Laurentian Great Lakes•What is biocontrol?•Know how individuals can help prevent the spread of invasive species.
Points to know