#35 & 36 conservation biology

Question 1

how many times have mass extinctions occured?

Answer 1

5 times in the past

Question 2

how many species have gone extinct since 1550’s

how many are threatened

Answer 2

850 species have gone extinct

2400 are threatened

Question 3

what species is the most threatened species

why

Answer 3

amphibians
habitat loss, fungus, pollution, predators
42% species threatened

Question 4

where has the worst mammal extinction rate?

Answer 4

australia
extinction rates well over the background rate
extinction rates in australia per captia are high

Question 5

what is functional extinction

Answer 5

• this is when there are so few individuals of a species left, they no longer perform its previous functions / interactions in the environment
  i. e. Gilberts Potoroo - perform digging, helpful as it moves the soil around. It is endangered so cannot provide that function effectively anymore

Question 6

what is the extinction debt

Answer 6

• the time lag between habitat disturbance and extinction of species in that habitat
• We still have a large extinction debt to pay - we have altered the habitat of many species but have not fully paid the price yet
  (if we act in this time lag we may be able to counteract our debt)

Question 7

what are they key threatening processes to species?

Answer 7

• land-use change: habitat loss & fragmentation
• habitat modification
• invasive species
• over-harvesting
• disease
• climate change
• altered disturbance regimes - fire, less flooding etc etc.

Question 8

what is the ecocentric view

Answer 8

• All species (including humans) are part of an interconnected nature
• Both individual species and nature as a whole have value
  Tends to focuses on ecosystems and their properties (e.g., maintaining ecosystem properties & processes)

Question 9

what is the biocentric view

Answer 9

• All individuals of all species are morally considerable and we have an ethical obligation towards them (we have an obligation to protect them)
• This includes a duty not to harm any individual in the natural world, unless needed to satisfy vital needs or in self defence
  However there is an issue with this as we want to get rid of pests like weeds and feral animals