sixth great mass extinction

Question 1

what extinction was the end of the dinosaurs?

Answer 1

• end cretaceous, 65 MYA
• K-T extinction, 85% of species went extinct
• causes: climate change, volcanism, meteorite impacts

Question 2

sixth mass extinction

Answer 2

• currently occuring, caused by people?
• many large land birds and mammals have gone extinct when humans arrived 10,000 years ago
• pleistocene extinctions cause/influenced by humans

Question 3

5 mass extinctions

Answer 3

late cambrian 500 mya
late ordovician 440 mya
late devonian 265 mya
end permian 245 mya
end cretaceous 65 mya

Question 4

in recent times the pace of extinctions has…

where are birds becoming extinct most?

Answer 4

• extinction rates has increased

- most dying bird species are on islands since the 1600s, when humanity started expanding by boats?

Question 5

passenger pigeons

Answer 5

• once accounted for 25-40 percent of total landbird population of US, about 5 billion birds
• people hunted PP for food, fertilizer, and live trap shooting
• main component of slaves and servants in 18th/19th century america
• by 1890s, laws passed to protect them, but recovery was impossible

Question 6

in the last century major causes of extinction have shifted from hunting to…

Answer 6

habitat destruction (for logging, agriculture), introduced species, climate change

Question 7

global amphibian decline

Answer 7

• 32% of known species are threatened with extinction
• 43% are declining
• most threatened species in the tropics

Question 8

chytrid fungus

Answer 8

-originated in south africa, spread via global trade in 30s-60s

Question 9

human population…

Answer 9

may stabilize at 9-10 billion, if not we’re fucked!

Question 10

current CO2 levels are…

Answer 10

at 395 ppmv, highest theyve been in 20 million years

Question 11

global temperature over the past thousand years has

Answer 11

-spiked in the past 150 years!

Question 12

how does change in temperature affect birds?

Answer 12

-changes migration and egg laying timing, as well as flowering of plants

Question 13

mean number of days changed per decade for birds

Answer 13

6 days for birds,

five days for amphibians

Question 14

global warming as sea levels

Answer 14

-sea levels are rising, and will continue to do so even if greenhouse gas levels are held at current levels and not rising

Question 15

COSEWIC

Answer 15

committee on the status of endangered wildlife in canada
-canada’s method of endangered classifications
-uses a combination of science, aboriginal traditional knowledge, and community knowledge
-

Question 16

what birds are declining in canada, increasing?

Answer 16

• aerial insectivores declining, raptors and waterfowl increasing
• species most at risk are those most impacted by human activities
• migratory species more at risk