Midterm #2: 2. Biodiversity: Human causes of extinction Flashcards
1
Q
what are the main loses of biodiversity?
A
- habitat alterations
- commercial fishing and hunting
- introduction of alien species
- sport and subsistence hunting and fishing
2
Q
what is habitat alteration?
A
- the physical change of habitat
- its the most significant cause of extinction (30%)
- includes urbanization, farming/agriculture, road building, forest harvesting, mining/oil/mineral extraction, recreational areas
3
Q
what are the 3 sub groups of habitat alteration?
A
- Habitat loss: the permanent loss of a habitat (ex: urbanization)
- Habitat degradation: Simplify, change, convert from the natural form (ex: farming, agriculture or ranching)
- Habitat fragmentation: breaking up the habitat into small pieces (ex: roads)
4
Q
what is commercial hunting and fishing?
A
- harvesting a wild species so you can sell it on or in a market (20%)
- legal and illegal (poaching)
- ex: cod fishing (commercial fisheries)- legal
- ex: illegal- horns or tusks from rhinos and elephants
5
Q
what is sport and subsistence hunting and fishing? what are examples of subsistence hunting?
A
- Pleistocene: time period w/ mammoths, rhinos, dire, wolves, sabre-toothed tigers
- 56 species of large mammals , 21 species of small mammals, and several species of birds all went extinct
- the galapagos tortoise, bush meat, primates
6
Q
what happened to there peregrine falcon?
A
- pest and predatory control was the reason they almost went extinct
- they were brought back by:
- banning DDT
- captive breeding program
- they are a good example of how we can bring a species back from the brink of extinction
7
Q
what happened to bison?
A
- they almost went extinct due commercial hunting by indigenous people
- captive breeding helped with reintroductions
- very valuable in their ecosystems
8
Q
what is citizen science?
A
- a partnership b/w scientists and non-scientists to collect data
- ex: eBird- citizens and scientists have made observations of 5 million birds per month
