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Invasive species in Victoria - Coggle Diagram
Invasive species in Victoria
Feral Cats
Impact on ecosystems and biodiversity
Feral cats are implicated in the extinction of 25 native, small and medium-sized mammal species
threaten the survival of over 100 other native species in Australia
Feral cats directly affect native species
may also increase the impacts of other threats to biodiversity
annual predation impact by feral cats on Australian native wildlife suggest one billion five hundred fifty-seven million killed
It is difficult to place a dollar value on the environmental impacts of feral cats.
Population
Cats may have arrived in Australia as early at the 17th century
it is believed that European settlers brought them out as pets during the late 18th century
feral cats exist over much of Australia and have successfully colonised most habitats
Cats were also deliberately released into the wild during the 19th century to control rabbits and mice
Feral cats are widely distributed throughout Victoria including several offshore islands
Feral cats usually reach their highest densities on small islands or in human-modified habitats
When prey is abundant, cat populations may increase rapidly, but when food becomes scarce, they typically decrease
Appearance
Long hair is uncommon for feral cats
The most common colour is a striped tabby
Persian or Siamese, are not found in feral populations
feral cats grow larger than most domestic cats
difficult to distinguish from domestic cats
Some deliberately bred characteristics of domestic cat breeds, such as very long coats or flat faces, are not common in feral cats
Foxes
Diet
they eat a variety of meat, insects, and plant materials
Consists of a lot of native animals
rabbits make up a bulk of fox diet
Foxes mostly prey upon animals weighing between 35 to 5500 grams
Most spectate to predation is poultry newborn lambs goat kids deer fawns domestic emu and ostrich chicks.
common food items include: carrion, house, and mice insects
Behaviour
Mainly nocturnal
Foxes may travel from 10-15km per night
Most active from dusk to dawn
Hide during the day
Foxes also bury food to eat later
Foxes will travel outside their home range to access seasonally abundant food
Adult foxes and cubs will defend cached food and will move it to another location if disturbed by other foxes.
Population
density often higher in urban areas
Victorian habitats are highly favourable for foxes.
After 20 years of their arrival, they were declared a pest species in Victoria
Introduced in the mid 1850's
foxes are found in a range of environments
Today foxes occur over 75 per cent of Australia
Most foxes were released in Melbourne
Feral Goats
Population
Have been present in Australia since early settlement
Spread across 35% of Australia and occur on many offshore islands
Goats were introduced to many areas by early settlers, miners and railway construction gangs for meat and milk.
Feral goats have also been sighted in many state and regional parks and forests throughout Victoria.
Factors that influence feral goat distribution include food, water and shelter.
Cashmere and Angora goats were introduced to Australia in the mid-1800s
Early populations were first near settlement areas
Appearance
Both male and female goats have distinctive curved or corkscrew shaped horns, although some may be hornless
Adult goats weigh between 40 and 60 kg
kids weigh about 2.6 kg at birth
Male kids are heavier than females
their hair type with it being either short, long, curled, silky or coarse
Goats may also have wattles (hanging fleshy lobes) on the neck and beards
Behavior
Feral goats are highly social animals
They have complex systems of communication including smell, sight and sound.
Female goats leave the group to give birth in a protected place
Feral goats are most active during the day
Feral goats often use sense of smell instead sight to find food.
A goats home range will revolve around water
Female goats may snort loudly and repeatedly to alert nearby goats.
Rabbits
Habitat
extensive burrows or warrens for shelter
fallen timber, logs, and rocks make ideal shelter
Rabbits warrens are typically larger and and more complex in deeper soils
without protection, rabbits are unable to successfully reproduce
Soil has an influence on rabbit density
Warrens are the key to the success of rabbits
Behaviour
Most active from dusk to dawn
move further away from the warren as it gets darker
when threated, they will crotch down or freeze
Dominant males typically defend a territory to gain mating rights to females
dominant females defend access to nesting sites
The territory of rabbits varies from approximately 0.2 to 2 hectares
Rabbits will respond to threats by thumping the ground with their back legs
Appearance
they are small mammals
Long hind legs and shirt front legs
Long ears
unique upper teeth
weigh from 0.8kg- 2.3kg when they are adults
slightly protruding eyes
A rabbits fur is typically grey-brown