Please enable JavaScript.
Coggle requires JavaScript to display documents.
Selection pressures on the Cane Toad in Kakadu National Park download-1…
Selection pressures on the Cane Toad in Kakadu National Park
Kakadu National Park
Abiotic factors
water
Essential for all animlas
major source of water in Kakadu National Park
Jim Jim falls
Has lots of cane toads
limited water in dry season
climate
monsoonal
Wet season
Dry season
Soil
during wet season
full of nutrients
Good for plant growth
Good for cane toads to hide.
Sunlight
important for plant growth
May affect cane toads
can get dried out
Biotic factors
Animals
Vital aspect of food chain
serve as prey for other animlas
return nutrients to the soil
Eg (in kakadu)
Northern Quolls
flat-back turtles
crocodiles
Autotroph
plants
are producers
vital part of food chain
habitat
eg. Quolls living in logs
Heteriotroph
Bacteria
Decomposition
Relationship between factors
abiotic factors support life
eg. habitat
eg. sunlight
negative impact on abiotic factors
negative impact on biotic factors
positive impact on biotic factors
positive impact on abiotic factors
biotic factors (sometimes) help abiotic factors
eg. decomposing --> nutirents in soil
type of environments its includes:
Savanna Woodlands
Monsoon Forests
Stone Coountry
Tidal Flats and Coast
the most prominent environemnt
the enviroment cane toads prefer
Floodplains and Billabongs
Southern Hills and Ridges
Effect on environement
Affects tourism
Brings less money to the park
park cant maintain the site
$1000000 donated to preserve
given to CSIRO
to control cane toad population
Adaptations
Behavioural
hides in moist crevaces
survive temps 5 - 40 degrees
Nocternal
survive loss of 50% of body water
Moves in straight lines
moves faster
occupies watery habitats
inflates lungs to appear bigger
wards off preadtors
Structural
Are bigger
Can eat more prey
Have longer legs
move faster
used to move 10km/ year
Now move 40-60km/ year
Physiological
poison
secrete bufotoxin
Highly toxic
Fatal
kills natural predators
Effect on other species
Decline in populations of (in Kakadu)
Northern Quolls
Catching program
Caught 66 quolls at start of decade
Caught 3 quolls at end of decade
Disrupts food chain
what they eat will rise in population
mice
lizards
birds
their predators will decrease in population
Owls
Dingos
Released 'cane toad' smart Quolls
try and raise populations
Large Goannas
Due to its poison
Their predators die
Loss of habitat
Cane toads destroy underground burrows
eg.
destroy 1/3 of rainbow bee-eaters burrows
Selection pressures
heat
Skin needs to remain moist
low water
dry desert environment
Kakadu has lots of water
needs water to survive
needs water to breed
has few preadators
Niche
Occupies niche of
In Kakadu National Park
mainly tree frogs
Ground frogs don't eat large prey
eg. Brown Clicking Froglet
as they are small
eg. green tree frog
ground dwelling predator
eats snails
eats insects (land and aquatic)
2 hypothesis
Competitive niche theory
competes other species for niche
Empty niche theory
Cane toads unlike other Australian frogs
They are larger
This helps
increase resistance to water loss
Increased mobility
Wider diet
Cane toads fill an empty niche
toad fills an empty niche
Selection pressure influences adaptation
Cane Toad population
introduced to Australia
1935
estimate of 200 million on Australia
North-eastern Australia
