Introduced Species
Loss to
habitat-destroying exotics
Native = indigenous
Endemic species
Exotic organism = non-indigenous species = Introduced organism
Feral animal
Invasive species.
Invasive exotic
Currently about 4,000 animal and 2,300 plant species in US
42% of endangered species due to exotics in some way.
Pathways for invasions:
produce - vegetables and fruits
container
traffic
ballast water
air traffic
agriculture
forestry
aquaculture
ornamentals
pet trade
horticulture/ornamentals and their dirt or packing materials
Consequences of invasions
outcompete natives for resources
interrupting food webs
displaying natives
preying on natives
introduction of diseases
smother natives
Usually have no predators nor diseases nor competitors in new habitat.
Exotic species
(introduced species)
Mammals:
house cats and feral
cats - Cats and wildlife - Indoors and
neutered only! Also, dogs, pigs, goats.
Birds:
Fish: Map
Pathways
for fish introductions
Snakehead
fish Mobility Dead Map
Invertebrates:
imported red
fireants or visit this site: http://fireant.tamu.edu/
stings,
mounds,
on water,
Texas
counties with quarantine, as
predators, impact on
wildlife
Africanized Honey Bees: http://honeybee.tamu.edu and Map
zebra
mussels: - Map and WOW! Economic
damage
Plants
Chinese tallow trees: http://www.usgs.gov/invasive_species/plw/cogongrass.html and http://tncweeds.ucdavis.edu/alert/alrtsapi.html
Kudzu - the vine that ate Georgia: http://www.maxshores.com/kudzu/
Solutions
1.
prevention - cheapest alternative - strict laws, strictly enforced
2.
control/eradication
In some
cases, control may be achieved via biocontrol, that is, using a
natural enemy, parasite, disease, or herbivore to control an exotic. In
biocontrol it is imperative that the control agent be proved to specialize on
the target species without ever expanding to alternative host species. Because
of this requirement, biocontrol agents are always insects, bacteria, or
viruses.
Don't
release unwanted pets!
Don't
plant invasive plants!
