Invasive species (class 13) Flashcards
(44 cards)
How many organisms have invaded the Antarctic continent in the last 200 years? Why/how?
About 200 plants, animals, inverts, and microbes. Human assisted species dispersal!!!
Give an example of an invasive species to the Antarctic and why it can survive there?
The king crab can survive in the Antarctic because of warming water temperatues
What did the study by Chown in 2012 of Antarctic visitors upon vacuuming their belongings?
People carried seeds on their clothes or gear. Scaled to everyone, there is 7,000 seeds being brought in anually
What percentage of the foreign plant material that reaches Antarctica are cold adapted species that can withstand & colonize in extreme conditions?
49-61%
Define “exotic species”
species occuring outside of their natural ranges because of human activity
Why do most exotic species not become established?
The environment is not suitable of they have not arrived in sufficient numbers
Define “invasive species”
species that become established outside their natural range and spread and increase in abundance rapidly
What is the risk of invasive species?
They may displace native species through competition or prey on native species to the point of extinction
Introduction of a new species occurs via: (4 ways)
- European colonization
- Agriculture, horticulture and aquaculture
- accidental transport
- biological control
Describe introduction via European colonization
settlers released 100s of species of bird and mammals to make countryside more familiar and to provide game for hunting
Describe introduction via agriculture, horticulture and aquaculture
species introduced as ornamentals, for agriculture, pasture grasses, or soil stabilizers. They can escape cultivation and become invasive.
Describe introduction via accidental transport
- weed seeds harvested along with commercial seeds and sown in new locations
- rats, snakes, insects stow away in ships and airplanes
- pathogenic organisms travel with their hosts (fungus, seeds, microorganisms, marine organisms)
Describe introduction via biological control
To control an invasive species, an animal from their original range may be released. Sometimes successful, sometimes becomes invasive and harmful themselves
Name one invasive species in North America
EARTHWORMS! They outcompete native species. They change the physical and chemical properties of the soil
What are domestic cats a major predator of?
Birds and small animals (in areas occupied by humans)
What does the invasive fire ant compete with?
Nestling bobwhites and fire ants compete for insect prey
Do many island plants produce bad-tasting tough vegetation that discourages herbivores?
No lol
What kind of plants have better defenses against introduced predators?
Exotic plants
What kind of plants take over islands following herbivore introductions?
Exotic plants
What makes some groups of island birds vulnerable to introduced predators?
Some island birds have lost flight and make their nests on the ground
What makes island organisms more susceptible to mainland diseases?
They lack natural immunity carried to the diseases carried by introduced hosts
Give an example of an island bird with their nest on the ground and name the introduced predator.
Cape Barren goose, Maria Island in Tasmania. Tasmanian devils were introduced to the island to create a disease-free pop., but have eaten all the goose nests
How are freshwater systems similar to oceanic islands?
They are both isolated with many endemic species
Are invading fish more or less aggressive than the native species?
MORE aggressive native species
