Lecture 15- Rainforest animals 2

Question 1

What are some examples of faunal links between Australian fauna and PNG and Asian fauna?

Answer 1

-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

Question 2

What are some characteristics of Flying foxes?

Answer 2

-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

Question 3

What are some characteristics of giant white tails?

Answer 3

-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

Question 4

What can geographic or habitat barriers lead to?

Answer 4

-geographic or habitat barrier can lead to population divergence over time, potential for speciation to occur (eg. green and common ringtail possum)

Question 5

How many tree kangaroos are there in Australia?

Answer 5

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

Question 6

Where were the tree kangaroos originally distributed? (in fossils)

Answer 6

Fossil record for tree kangaroo distribution: once widespread, distribution contracted with rainforest contraction

-now contracted, limited distribution

Question 7

How many tree kangaroos are there in PNG?

Answer 7

-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

Question 8

What are endemic species?

Answer 8

-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

Question 9

What are some characteristics of the Long-tailed Pygmy Possum?

Answer 9

• rainforest endemic
• only in little bit of Australia
• live on nectar and insects
• they evolved in the Australian rainforest
• occur in low densities

Question 10

How many endemic species are there in tropical rainforests in Australia?

Answer 10

-59

Question 11

What are the characteristics of golden bower birds?

Answer 11

-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

Question 12

What are characteristics of Boyd’s forest dragon?

Answer 12

-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

Question 13

What are the characteristics of orange-thighed frog?

Answer 13

-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)

Question 14

What are the characteristics of Musky rat kangaroo?

Answer 14

• 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

Question 15

What are the key issues for endemic species?

Answer 15

• 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

Question 16

What are the four key conservation issues?

Answer 16

1. Habitat loss 2. Impact of indigenous hunters 3. Poaching 4. Disease

Question 17

How is habitat loss a problem for fauna?

Answer 17

-extensive clearing of tropical rainforest is a direct threat to fauna -intensive clearing in most inhabited areas -have nowhere to live

Question 18

How much of the tropical Australian rainforest has been impacted by clearing?

Answer 18

* 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

Question 19

How was the Ulysses Butterfly impacted by habitat loss?

Answer 19

-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

Question 20

What is the impact of indigenous hunters on the fauna?

Answer 20

-increasing human popns & development, along with continuing traditional hunting -in some parts still have many hunters (PNG)

Question 21

What is the impact of poaching on tropical fauna?

Answer 21

-Wealthy animal collectors drive poaching of rare species for private collections

Question 22

What is the impact of disease on tropical fauna?

Answer 22

-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

Question 23

What are the frogs that arrived recently and which are the Gondwanan?

Answer 23

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

Question 24

How do mammals differ depending on their time of arrival or evolution in Australia?

Answer 24

• 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

Question 25

What are some animals that are good in dispersing seeds?

Answer 25

* Bats (flying foxes): can fly long distances, also mixing genetic material between plants * Cassowaries: * Musky rat kangaroo -fleshy rainforest fruits evolved

Question 26

How are cassowaries important for seed dispersal?

Answer 26

* 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?

Question 27

How is the musky rat kangaroo important for seed dispersal?

Answer 27

-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

Question 28

What is the role of animals in nutrient cycling?

Answer 28

• 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!

Question 29

What are the topics we discussed in relation to rainforest fauna?

Answer 29

• Diversity - Links between Aust.n & PNG rainforest fauna - Many endemic species - Loss of species - Early vs recent fauna - Animals & seed dispersal - Animals & nutrient cycling