Lecture 1- Introduction Flashcards
What is a numbat?
-rare marsupial now remain.ing only in southern Western Australia, devastated by introduced species(dogs, cats), only comes out at night and feeds totally on termites. Hard to keep in preservation projects as you have to feed them fresh termites
What are the three main influences on the development of the current Australian faunal assemblages?
- ancestral fauna
- recent arrivals
- environmental influences
Where did the Australian fauna come from?
-Gondwana (India, Africa, Antarctica, Australia-PNG, S America, New Zealand)= so fauna has connections to the faunas of those parts of the world as well
How Australia came to be isolated?
-breakup of Gondwana =India 140 MYA =New Zealand 80 MYA =Oz from Antarctica 50-60 MYA =Oz hit Asian Plate 15-20 MYA -isolated for approx. 40 MY
What is the world distribution of marsupials?
-asutralia, PNG, S America and bit of N America
But none in Indonesia!!!= because they can’t swim or travel there.
What is the Wallace line?
-some birds on both sides but not marsupials= because they can’t swim or fly so they couldn’t cross over, except when natives brought some over on the islands as food etc.
What are platypus and lung fish examples of?
-ancestral fauna, Gondwanan origin
Where did rodents, dingoes and bats come to Australia from?
-Asia
What are some examples of animals brought to Australia from Europe?
-fox, toads, cats, dogs
Were current faunal assemblages influenced by radiation in isolation and past species losses (exctinct)?
-yes
How did the Environment influence the faunal assemblages?
- environmental components= climate and geology
- ecological components= vegetation
What are soils like in Australia and why?
- nutrients aren’t brought to the surface as it’s so flat due to being geologically stable. The wind etc= leached soils, low in = potassium, phosphorus and nitrogen
- low topography
How did the Australian climate change in the past?
- 50-60 MYA= humid, temperate, rainforest
- 30 MYA= circum-polar currents, increasing aridity
- 15 MYA= moving north, warmer
- Australia wasn’t as much in the north as it is now so it changed as it was moving towards the equator
- the climate that is around the coast used to be more common inland
What is the deal with wildfire?
-increased in frequency as the continent dried
-possibly increasing with climate change
-occurs in mosaics
-different fires in different bits of Australia= vic has higher frequency and faster fires than Queensland
-regeneration of plants after fire. Some areas in lowlands need fire and fire resistant
-alpine areas aren’t that fire resistant so we never get those back if lost in fires (Tas)
-in some parts fire is important for the preservation of the ecosystem and habitats:Lower storey plant regrowth & regeneration: provides food (e.g. for wallabies, possums and koalas) + cover (structural habitat elements) for all animals
-2 seeks after fire:Fallen trees are important habitats
-2 yrs after fire: Retaining large habitat trees:
shelter for wildlife (tree hollows = nest sites for possums & micro-bats)
How are alpine areas affected by fire?
Alpine areas - very slow or no recovery, even in med to longer term, after fire in: major issues for rare alpine species combining with reduction in suitable habitat area due to global warming/climate change
