Lecture 14- Rainforest animals 1 Flashcards
What are the two main australian tropical rainforest vegetation types?
1.Tropical rainforest: high animal diversity (also called closed forest) 2.Temperate rainforest: lower animal diversity
What are some characteristics of tropical rainforests in Australia? (structure, canopy cover and max. canopy height)
-complex structure -70-100% canopy cover -max.canopy height 40-50m -only in the northern parts of the East coast -sea level to 1600m
What is rainfall like in tropical rainforests in Australia?
-reliable above 1500mm/year
How much of the land in Australia is tropical rainforest?
-only 1-2% of total land are of Australia
What is species richness in different altitudes in tropical rainforests in Australia?
-Sea level to 1600m - upland RF (cooler), fewer animal species - lowland RF (below 1000m), more species, warmer and heavily impacted by human activities
What is the main difference between temperate and tropical rainforests?
-temperate have fewer species and animals that are there are less abundant
What is the tropical rainforest diversity?
-the rainforest can support a huge diversity of organisms
How many invertebrate species are there in tropical rainforest?
-number of invertebrate species unknown (over 75,000 sp. known only from Australia’s tropical rainforests) -tested by misting tree with insecticide and collect bugs at the bottom -e.g. scarab beetle -about 60% of butterflies are in the wet tropics
Where is the tropical rainforest in Australia?
-
Up to which altitude do rainforests occur?
1600m
What are some characteristics of turquoise earthworm?
-can get up to 60cm long -can be couple centimeters thick -not known well
How many bird species are there in the tropical rainforest in Australia?
-area of very high bird diversity for Australia: 16.5% (128 species) -e.g. palm cockatoo (rainforest specialist, large bird, it is poached, slow breeder,of conservation concern)
How many reptile species are there in the tropical rainforest in Australia?
-160 reptile sp. (23% of Australia’s reptile fauna) -e.g. lace monitor (goanna), up to 2m long
How many frog species are there in the tropical rainforest in Australia?
-47 frog species (23% of Australia’s frog fauna) -e.g. Lesueur’s tree frog: very common, sitting on rocks, the male is much smaller, males are yellow, the females go to the males to the stream
How many mammal species are there in the tropical rainforest in Australia?
-89 mammal species, (33% of Australia’s mammal fauna) -have possums, monotremes, musky rat kangaroos
What is the distribution of striped possum?
- also in PNG, in the closed forest and the adjacent forest to it
- doesn’t live in dry areas
What are the constraints for research in tropical rainforest?
* remote *often logistically difficult *wet season flooding and isolation
What are the key ecological questions on striped possums?
* diet * habitat use and area requirements * comparative studies with closely related species General “rule” on area requirements: herbivores < carnivores/insectivores
What is the general rule about area requirements?
-herbivores need less area than carnivores or insectivores
What are the known diets of other Petaurid possums?
* Plant exudates (sap, gum, nectar) a major component of diet * Smaller species supplement diet with invertebrates
What family are the striped possums in?
Petaurids
What are some unusual morphological characters of Striped possums? (3)
* Klinorhynchy (rounded cranium, very rounded skull, harder to break) * Large procumbent lower incisors , move separately * Tongue & 4th finger elongated
How does a hand of striped possum compare to a typical petaurid hand and what may that mean?
Morphology suggest specialised diet of invertebrates
Prediction: that striped possums are insectivores & will therefore require much larger areas of habitat than other petaurid possums
What is the diet of a striped possum?
Specialised insectivore: * wood-boring beetle larvae and social insects very important in diet (high fat content, very energy rich) * other invertebrates taken opportunistically * exudates used occasionally (sweet)
What is the habitat range of striped possums?
-Radio-tracking data showed that habitat requirements are huge compared to other petaurid possums
Why do tropical rainforests support high animal diversity?
- patchiness (potential speciation) - high complexity, lot of places for animals to specialise in - high productivity, lot of food for animals, don’t have to compete for food
What may a tropical rainforest in North Queensland represent?
-quite large areas of habitat -However there may be barriers to movement which restrict/prevent populations of some species from mixing
What can habitat patchiness result in on a local scale?
-Habitat patchiness (on a local scale) can result in the isolation of sub- populations of some species (potential for speciation) -e.g.Rainforest patch, surrounded by dryer (eucalypt) forest: a potential habitat barrier
What can habitat patchiness result in on a larger scale?
-Larger scale, geographic barriers (e.g. valleys between mountains) can also result in the isolation of sub-populations -e.g PNG: some tree kangaroo populations isolated on mountain tops
What changes the impact of habitat or geographic barriers on animal species?
-mobility (bat= mobile, antechinus= can only walk a mile) -body size (if larger body size have bigger capacity to cover more distance) -degree of habitat specialization
How does high complexity affect species richness in tropical rainforest?
-high complexity (e.g. Red Bellied Pitta specialises on rainforest snails, carnivorous birds exploit high complexity) -high productivity
How does high productivity affect species richness in tropical rainforest?
-high productivity -many rainforest trees produce fleshy fruits -Frugivorous (herbivorous) birds exploit high productivity & lots of fleshy fruit -e.g. Super Fruit Doves
What is common in tropical rainforests?
-bit less synchronous -so seeds and flowering occurs all the time so birds in particular can eat it -Tropical rainforest trees often fruit heavily and are used by many species -e.g. Fig Parrot -so in rainforest less competition for food, enough for everyone
What is temporal separation?
-Temporal separation in resource use: birds feed during day, mammals feed at night –Feathertail glider feeds on nectar at night; honeyeaters butterflies & friar birds feed during day(hard to see in Vic but common in tropical forest)
What is an example of faunal link with PNG and Asia (from Australia)?
- Buff Breasted Paradise Kingfisher
- Over-winter in PNG
- Migrate Oct/Nov to breed in lowland rainforests of Cape York - Form pairs, establish territories, nest in termite mounds
- occur below 600m -go for rich soils -breed in the lowland forest
- nest in termite nests on the soils, dig holes into the termite mounds and inside it they then nest
- adults migrate before juveniles, juveniles follow later
Summary:
- Australia’s tropical rainforest fauna survives in very small area of the continent - Diversity very high across all animal groups (due to habitat patchiness, complexity & high productivity) - Links between Aust.n & PNG rainforest fauna
What is the main geographical barrier between PNG and Australia?
-Tores Strait -barrier for non-mobile species -lowland PNG is similar to Australian lowland -share 50% of bird fauna between the two places
