FNR 240 Lec 16

#1

Native species:

a species that, other than as a result of an introduction, historically occurred or currently occurs in that ecosystem

Alien (Exotic/Non-native):

any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem

Invasive species:

means an exotic/alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.

Introduction:

the intentional or unintentional escape, release, dissemination, or placement of a species into an ecosystem as a result of human activity

Feral:

Animals or plants that were at one time domestic that have been released or escaped and now survive in a more wild state

Feral Hogs Population

Around 2 million of them

Non-native species are always invasive when introduced to a new system.

False

Impacts of invasive species

IMPACTS:

 Second most significant impact to T & E (and all) species next to

habitat loss.

 Decrease native biodiversity

 No co-evolution

 Hybridization

 Decrease function of ecosystems and ecosystem services

 Displace native plants that wildlife and fish depend on for food

 Diseases

 Cost - one estimate on mitigation - $123 Billion/year

Unintentional alien species

Pets released/escaped, ships/boats, wood, travel, and recreation

Intentional alien species

Agriculture, hunting, make feel more like home, and biological control.

Characteristics of invasive species

R-selected, generalists, natural pressures are missing, and degraded habitat

Asian carp, rabbits, cane toads, kudzu, grey squirrels, killer bees, starlings, northern snakehead, zebra mussels, and Burmese python

Top ten invasive species

Zebra Mussels origin

Eurasia and brought by ballast water of ships

Feral Cats

Bring disease, declined bird pops, unneeded effective predator, and humans like them so they can be controlled like usual.

Non-invasive exotic species

Pheasants and exotic ungulates

Costs of invasive plant infestation

around $120 billion

How to reduce invasive plant species

Mechanical control (hunting, culling, capture/trapping, pulling), Chemical control (pesticides, poisons), education/awareness, legal control, and biological control

Culling

Reduction of a wild animal population by selective slaughter

Biological control

Control of invasive plants and insects by insects quite safe and often
effective.

Biological control etc.

Cane toads were introduced as a form of biological control but failed and became invasive and in general vertebrates are bad for biological control

Generalists

Species that preys on many different of things

Specialists

Mostly insects and species that only feed on one or few other species good for biological control

Specialists etc

Invasive species can be controlled by predators from their own area and its hard to get approval to release a biological control without a lot of testing/approval

Eradication of an invasive species is most effective when public

True

Zebra mussel feed

Use filter water to feed and one can filter a quart of water per day

Zebra Mussels eggs

Reproduce extremely quickly and larvae are microscopic so they spread fast

Zebra Mussels Costs

Clog pipes/machinery in power plants, water treatment plants and cleaning/preventing costs are millions of dollars

Retrofitting

Adding special filters or coatings to equipment

Native mussels dissapearance

Getting cooked by Zebra mussels

Zebra Mussel risk

Can cut and injure people’s feet mostly swimmers

Texas

Hunting on private ranches became a big business

Mammals introduced exotic

Aoudad sheep, Axis deer, Elk, Sika deer, Fallow deer, Blackbuck antelope, Nilgai

antelope, Russian boar, (&Feral hog)

Birds introduced exotic

Emu, Ostrich, Rhea, Cassowary, Pheasant

Regulations for exotic animals

No limits on how many exotic animals (like axis deer, aoudad sheep, or pheasants) you can hunt or keep on private land, and there’s no closed season — you can hunt them year-round.

Regulations for exotic animals reasons illegal

• Hunt without a valid hunting license — you still need proper licensing.

• Hunt on public roads or rights-of-way — for safety and legal reasons.

• Hunt without the landowner’s permission — you must have permission if it’s private land.

• Possess an exotic animal or carcass without the owner’s consent — you can’t take or keep someone else’s animals.