Exotic Species

Mrs. Black Horse, Cheyenne Nation, and dog travois

American Chestnut

Cracking From Chestnut Blight

Exotic Species

• Conservation biologists typically call introduced species “exotic species” - species which live outside their natural range

• Botanists typically refer to exotic plants as alien species

• Other terms you may see include biological invaders, introduced species, invasive species, non-indigenous species, non-native species (my preferred term)

Cattle EgretCame on its own – not exotic

How or Why Do Exotic Species Get Dispersed?

1. Stowaways

2. Subsistence and Commerce

3. Recreation

4. Whimsy or aesthetics

5. Science

6. Biological Control

Norway Rat as ship rat

Nightcrawler Earthworms (Lumbricus terrestris) and pre-exotic distribution

Cars transport seeds via mud stuck to car

Ballast Water Discharge

Commerce and Subsistence

Commerce and Subsistence

Monterey Pine

Blue Gum Eucalyptus

Feral Pig - Florida

Recreation - Brown Trout

Ring-necked Pheasant

Chukar

Red Deer – New Zealand

Whimsy or Aesthetics – European Starling

House Sparrow

Multiflora Rose

Tree of Heaven - Ailanthus

Light blue – counties where Ailanthus is present

Scotch Broom

Walking Catfish

Bighead Carp

Carp Jumping

Cherry Headed Conures in San Francisco

Monk Parrots – Chicago, Harold Washington Park and Hyde Park

Science - Gypsy Moth

Africanized Honey Bees

Movement of Africanized Honey Bees

Movement of Africanized Honey Bees

Biocontrol

Klamath Weed – aka – St. John’s Wort

Chrysolina beetle

Prickly Pear Hedge - Tunisia

Prickly pear in Australia – before control

Cactoblastis cactorum

Prickly pear – same location after control

Red Fox - Australia

With native Bobuck possum

Red fox - Australia

Impact of Exotic Species

Predators and Grazers – Stephen Island, New Zealand

Stephen Island Wren

Brown Tree Snake

Many Brown Tree Snakes

Brown Tree Snake on Guam and Beyond

Decline in cichlid species due to Nile Perch in Lake Victoria

California Channel Islands

Sheep grazing – Channel Islands

Channel Island Coreopsis

Emerald Ash Borer

Parasites and Pathogens16th Century Drawings of Native

Americans with Smallpox

Chestnut blight canker and fungus

Spread of Chestnut Blight

Dutch Elm Disease – The Way to Knox

Dutch Elm Disease – The Way to Knox

Elm Bark Beetle

Elm Bark Beetle Galleries

Avian Malaria and Hawaiian Native Birds like Scarlet Honeycreeper

Avian malaria occurs in areas below white line on Island of Hawaii

Avian Malaria and Abundance of Native Birds

Gray line – mosquito abundance; solid black line – prevalence of avian malaria; dashed line – native bird adundance

Competitors – Purple Loosestrife

Purple Loosestrife

Purple Loosestrife Distribution

Control of Purple Loosestrife

Expansion of Water Hyacinth from Native Brazil

Water Hyacinth in India

Kudzu flower

Kudzu vines

Kudzu Car

Kudzu Distribution

European Starling and Eastern Bluebird

Starling and Bluebird Competition

Honeybee – Apis melliflora and native Bumble-bee - Bombus vosnesenskii

Honey Bee – Colony Collapse

Hybridization – Cordgrass – Spartina alterniflora

Spartina Hybridization

A = Spartina alterniflora

B = S. maritima

C = S. x townsendii

D = S. anglica

Invasive Spartina anglica in San Francisco Bay

Ecosystem Effects - Blue Gum

Charles Elton - 1927