Why Species Are At Risk Flashcards
Give 5 ways human activity is destroying ecosystems.
Agriculture Forestry Urban development Mining Environmental pollution
A FUME
What is the normal ‘background’ rate of extinction?
1 species in a million every year
What are some examples of animals that have become extinct?
Moa
Megatherium (Giant Land Sloth)
Passenger pigeon
Thylacine
What are the 7 abbreviations that the IUCN use?
EX = extinct EW = extinct in the wild CR = critically endangered EN = endangered VU = vulnerable NT = near threatened LC = least concern
What are 6 reasons that species are threatened?
- Natural selection
- Non-contagious populations
- Loss of habitat
- Overhunting by humans
- Competition from species
- Pollution
Explain how natural selection threatens species.
Human activity causes habitats to change faster than successful mutations can occur, so species can’t adapt to their environment and are therefore driven to extinction.
Explain how non-contagious populations threaten species.
If groups are isolated from each other, species can’t interbreed. There can also be too little genetic diversity in each to ensure a healthy population, leading to extinction.
Give 4 ways that loss of habitat can threaten species.
Deforestation
Drainage of wetlands
Hedgerow loss
Farmers sowing crops in autumn
How are hedgerows advantageous?
They provide a habitat for insects
Nesting sites for birds and reptiles
Food for many species
Varying light intensity and water availability for diverse plants
Why is it that farmers sowing their crops in autumn rather than spring threatens species?
It means that plants are an unsuitable height for birds to build their nests so it leads to a decrease in birds.
What kinds of overhunting threatens species? (5)
Trophy hunting Traditional medical practices The bush meat industry Overfishing Agricultural exploitation
Give 2 examples of how competition from species and the accidental introduction of organisms has threatened species.
Rats from European ships ate dodo eggs
The American signal crayfish has invaded U.K. Streams and smaller native crayfish are being outcompeted
Give 4 ways pollution threatens species.
Oil spills kill plants and animals - Argentina 1999
Oil floats - prevents oxygenation of surface water
Birds feathers can’t insulate them as they stick together so they freeze
PCBs - neurotoxins, carcinogens and hormone disrupters - ingested with food
