Feral animals Flashcards
What are the names of some introduced (feral_ species?
cat
dogs
dingo aren’t considered feral species as they have been here for a longtime.
fox
pig
cane toads
why does australia have introduced feral animals?
Why and how were they introduced?
All Deliberate or “Accidental” Introductions
* Acclimatisation societies
– Introduce ‘useful and bountiful’ species
– Aesthetics, sport, food, ‘remind us of home’ species (e.g. rabbits, foxes,
deer)
- Escape captivity became a feral species
– Livestock, transport (e.g. horses, pigs, goats, camels)
– Mice, rats from ships
– Pets (e.g. cats) - bad cat management - ‘Accidents’ (e.g. Asian house gecko) still happening today, albeit mainly
insects (e.g. fire, crazy and electric ants) and marine organisms (e.g. Asian
green mussel) and plants (weeds) - Control of other pestspecies
– (e.g. cane toad, mongoose, fox?)
Why are they so successful?
- Scarcity of predators and diseases (i.e. high
survivorship/low mortality) - Can fill niches not occupied by native species
- Our modified environments are highly
suitable
4.. Naïve native species lack defence
mechanisms against predators (e.g.
foxes) exacerbated by fragmented
habitats (e.g. that reduce cover)
– Modified environments have altered
ecology (e.g. less native predators; more
suitable for certain species)
– Highly successful when competing with
native animals for resources (e.g. goats)
- Often, aspects of their biology and ecology
favour their success
– high reproductive rate (e.g. rabbits, mice),
sexually-mature early
Use feral rabbits as an example, why are they so successful?
- Free from diseases
- Relatively few
predators - Short gestation period
+ large litter size +
early sexual maturity - In 18 months we go
from two breeding
rabbits to 180 rabbits! - Grazing pressure - they out compete the native species - macropod species
Why foxes successful in inhibiting australia?
- Introduced to Australia in the
mid-1800s for hunting - Few natural predators in
Australia - Adaptable to different
environments and habitats
(except tropics) - Scavengers and opportunistic
predators which means they eat; Eggs, birds, rodents, marsupials, lizards, frogs, insects, fruits - Carrion – sheep, kangaroo
Why are feral pigs successful?
- Extreme generalist forager
- Crops, fruits, seeds, leaves, stems, roots
- Fungi, invertebrates, bird/turtle eggs
- Predation – rodents, small marsupials,
birds, snakes, frogs, lizards, salamanders - No natural predators
- Damage to habitat
- Competition for food resources
how do feral pigs impact australia?
Destroy the environment
Where do feral cats come from?
Where did they come from?
* Irresponsible actions of people who
abandon their unsterilised cats or allow
them to roam outdoors unsupervised
- Lack of natural predators
- Adaptable
- Proficient predators - multi animals
- Birds and small to medium-sized mammals
and marsupials, lizards, geckos, frogs
What is difference in the definitions of Feral, pest, resource?
and what makes feral animals a resource?
Feral a. -
(1)wild, untamed, uncultivated;
(2)existing in a wild state, especially
describing an animal that was
previously kept by people:
Pest n. - troublesome, annoying or
destructive animal
* (from French peste or from
the Latin pestis plague)
Resource n. - means of supplying what is
needed, stock that can be drawn on.
resource species
- feral pigs - hunting, sport
- fox - hunting, extract pelt (fur coat)
- rabbits - hunt, meat
- camels - travel, transport, camel milk (daries)
What are negative problems with pests?
- Reduction of agricultural productivity (competition with grazing stock for feed
and water, damage to horticultural crops, predation on stock, land degradation) - Environmental damage (competition with native species for food, water and
shelter) - Consumption of native species
- Spread of disease and/or parasites and weeds
- Attack, harassment, or annoyance threat to the community, particularly in the
urban environment - Damage to infrastructure (e.g. fences, dams, buildings)
- Damage to habitat (ponds, trees, vegetation)
- Cost and collateral impact of control measures
What are disease caught from feral animals?
Brucellosis (Brucella suis) = Foot and Mouth Disease FMD
Tuberculosis (Mycobacterium spp.) = Classical Swine Fever
Porcine Parvovirus = Aujeszky’s Disease
Leptospirosis (Leptospira spp) = Japanese Encephalitis
Melioidosis (Pseudomonas
pseudomallei)
Swine Vesicular Disease
Rabies
Screw-worm Fly infestations
Sparganosis (Spirometra erinacei) African Swine Fever
Murray Valley Encephalitis Trichinosis
What are pest benefits?
Employment
* Ecotourism/sport/hunting
* Game meat – pet and human
* Leather, fur, felt
* Fertilisers
* Ornaments/eggs/feathers
* Biological control
* Gelatine
* Breeding stock/ domesticated/ export / transport/ pets/ livestock
* Oil
* Research Drugs
* Education
In particular to feral pigs, what are the benefits?
They are considered a resource;
harvesting
hunting and sport
What is the issue with people finding feral pigs a resource, and those finding it a pest
why is the controversy towards feral animals?
People decide whether an animal is a pest!
– The pest is not the animal but the situation…..
– What is a pest to one person may be valued as a resource to another
* e.g. to a land manager a feral pig = pest (environmental damage)
* But…..
* to a harvester a feral pig = resource ($$$$)
– Such conflicting opinions is an important reason why pest control is difficult!
What are some examples of native marsupial pests? and what are examples of how they are pests
Koala (Phascolarctos cinereus)
– Killing eucalypts in Victoria and South Australia
– Overpopulation on Kangaroo Island (damage
to trees)
Agile Wallaby (Macropus agilis)
– Stripping undergrowth, eroding slopes and
soiling coral reefs on Hamilton Island
Tammar Wallaby (Macropus eugenii)
– Eliminating shrubs on Greenly, Granite
and Boston islands, South Australia
Common Brushtail Possum (Trichosurus vulpecula)
– Threatening endangered glossy black- cockatoos on Kangaroo Island
– Probably threatening red-tailed black- cockatoo in Victoria
– Possibly stealing nest holes from rare
masked owls in Tasmania
– Stripping and sometimes killing eucalypts
– Spreading seeds of hawthorn and other
weeds
– Possums are vectors of bovine
tuberculosis – threat to dairy, beef and
deer industry in NZ
