Lecture 15- Rainforest animals 2 Flashcards
What are some examples of faunal links between Australian fauna and PNG and Asian fauna?
-some mammals can cross the distance across the Torres Strait 1. Little Red Flying Fox: Flying foxes highly mobile, capable of long distance movements. Effectively one large population in Aust & PNG. 2.Giant White-Tailed Rat: distributed in Australia & PNG, but no movement between populations Torres Strait represents a geographic barrier for some sp. 3. Ring tailed gecko: not very well known, small just a few cm, also AUS and PNG, Torres strait is a barrier 4. Green Python: arboreal, nocturnal, occurs in PNG and AUS but Torres strait is a barrier 5. Amesthystine Python:Australia’s largest snake (to 8m), major predator in rainforest, specialise in eating vertebrates -with reptiles: no migration, thus PNG & Australian pop.ns now isolated: Torres Strait = geographic barrier
What are some characteristics of Flying foxes?
-very mobile, can fly across Torres strait so no geographical barrier between asutralia and PNG -colony is called a camp -mobile: very, between melbourne and sydney pretty common -very mobile -the only example without geographical barrier
What are some characteristics of giant white tails?
-big rain forest rats, feed on fruits and can eat some meet -can get rafted between the islands occasionally but there is a geographical barrier in the Torres strait
What can geographic or habitat barriers lead to?
-geographic or habitat barrier can lead to population divergence over time, potential for speciation to occur (eg. green and common ringtail possum)
How many tree kangaroos are there in Australia?
2 -Lumholtz tree kangaroo (north) and Bennet’s tree kangaroo (south) -separated by the daintree river, probably a geographical barrier -they are secondarily arboreal -nocturnal -quite large, up to 12kg
Where were the tree kangaroos originally distributed? (in fossils)
Fossil record for tree kangaroo distribution: once widespread, distribution contracted with rainforest contraction
-now contracted, limited distribution
How many tree kangaroos are there in PNG?
-more diverse than Aus -8 species -differ in what they looked like and where they live -some on mountain tops, pushed there by hunting -Doria’s tree kangaroo= occurs at high altitudes -Matschies’s tree kangaroo= also mountains -Dingiso= only known to western science in 1994 -they are in habitats that are not connected so lot of speciation, pushed by hunters to tops of mountains and cannot migrate
What are endemic species?
-Endemic species: unique to a particular geographic region or locality, assumed to have evolved there. -Large number of endemic species in Australian tropical rainforest, therefore should be given high conservation status if under threat -More endemics at higher altitude -if you lose endemic species, that is it nowhere else
What are some characteristics of the Long-tailed Pygmy Possum?
- rainforest endemic
- only in little bit of Australia
- live on nectar and insects
- they evolved in the Australian rainforest
- occur in low densities
How many endemic species are there in tropical rainforests in Australia?
-59
What are the characteristics of golden bower birds?
-occurs above 900m, feeds on fruit, males build a bower to attract females -the bowers can be 3m tall, makes them elaborate and decorates e.g. with pale green or blue things -they also dance to attract females -about 25 cm long -defend the bower against other males -steal stuff to get blue things from humans -restricted to higher altitudes
What are characteristics of Boyd’s forest dragon?
-little knowledge of biology, occurs in very dense rainforest areas, distribution: high & low altitude -more generalist species, from low to high altitudes -feeds on snails and invertebrates -sit and stay still approach -more generalist in food as well
What are the characteristics of orange-thighed frog?
-little knowledge of biology, only recognised as a distinct species in 1986 -only couple cm long, small -occur in dense rainforest -only males sing (as with all frogs)
What are the characteristics of Musky rat kangaroo?
- very limited distribution
- 700g, small
- ancestral group of the kangaroos
- have multiple young 2-3
- nest in trees
- totally rainforest dependent
- breaking rainforest into patches is bad
What are the key issues for endemic species?
- limited distribution (loss of habitat or population = loss of that species world wide) - often rare & difficult to study, often little knowledge of biology -problematic for conservation -already a specialist and at risk often -often rare and occur in low abundances
What are the four key conservation issues?
- Habitat loss 2. Impact of indigenous hunters 3. Poaching 4. Disease
How is habitat loss a problem for fauna?
-extensive clearing of tropical rainforest is a direct threat to fauna -intensive clearing in most inhabited areas -have nowhere to live
How much of the tropical Australian rainforest has been impacted by clearing?
* 23% cleared * 22% impacted by agriculture * 35% used at some level for forestry production I.E. 80% impacted by some form of human activities, only 20% undisturbed = huge potential impact on fauna
How was the Ulysses Butterfly impacted by habitat loss?
-loss of a small component of habitat can be high impact -in a rainforest system many subtle connections -dependent on one plant genus for oviposition: G: Melicope, caterpillars feed on it’s leaves
What is the impact of indigenous hunters on the fauna?
-increasing human popns & development, along with continuing traditional hunting -in some parts still have many hunters (PNG)
What is the impact of poaching on tropical fauna?
-Wealthy animal collectors drive poaching of rare species for private collections
What is the impact of disease on tropical fauna?
-e.g. Sharp-Nosed Torrent Frog (G: Taudactylus) threatened by chytrid fungus -chytrid fungus is a lot in frogs, mostly stream frogs -low temperature is good for the fungus
What are the frogs that arrived recently and which are the Gondwanan?
Gondwanan: Hylidae and Myobatrachidae new: Ranidae (barred frogs, only 1 species) -gondwanan species have more connection with the local fauna and flora, the recent not as mucg -Ranidae got here by itself
How do mammals differ depending on their time of arrival or evolution in Australia?
- Australian native rodents originated in Asia (i.e. relatively recent arrivals), -musky rat kangaroo a Gondwana group -native rodents are a recent arrival to Australia, they are good dispersers, good at rafting -early group is the musky rat kangaroo
What are some animals that are good in dispersing seeds?
* Bats (flying foxes): can fly long distances, also mixing genetic material between plants * Cassowaries: * Musky rat kangaroo -fleshy rainforest fruits evolved
How are cassowaries important for seed dispersal?
* Feeds on fruit and disperses seeds * Large birds, can carry large seeds & a large volume of seeds * Large home ranges (smaller at lower elevation) * Populations declining in many areas -highly mobile, move the seeds quite far -can eat a very big fruit as the only seed dispersers -How might loss of such species impact on longer-term rainforest ecosystem health?
How is the musky rat kangaroo important for seed dispersal?
-important seed dispersers in rainforest via scatter-hoarding -Contribute to forest regeneration and ecosystem health -white tail rats eat the seeds whereas the musky rat kangaroos eat fruits and dig a hole and bury it, scatter the seeds, don’t remember well where the seeds -they contribute a lot as white tail rats less likely to eat the seeds when buried by a musky rat kangaroo
What is the role of animals in nutrient cycling?
- Bulk of rainforest nutrients in plants
- lot of non-animal groups are important e.g. fungi, these are very abundant in a rainforest
- everything gets recycled very quickly in the rainforest
- wood boring beetle larvae, as soon as tree falls, beetles lay eggs (this happens throughout the year)
- termites also very important
- nutrient poor soils in the rainforests!
What are the topics we discussed in relation to rainforest fauna?
- Diversity - Links between Aust.n & PNG rainforest fauna - Many endemic species - Loss of species - Early vs recent fauna - Animals & seed dispersal - Animals & nutrient cycling
