Details of this species in Australia Status: Alien
Invasiveness: Invasive
Occurrence: Established and expanding
Source: Spencer and Hampton 2005; Dexter 2003 Arrival Date:
Introduction: Species Notes for this Location:
Feral pigs are a continuing threat, and are now found across 40% of the Australian continent (Hone 1990, in Spencer and Hampton 2005) at densities ranging from 0.1 to > 20 pigs per km2 (Pech and Hone 1988, Choquenot et al. 1996, Saunders and McLeod 1999, in Spencer and Hampton 2005). Estimates of the total Australian population size vary between 13 and 23 million, depending on environmental conditions (Hone 1990, Choquenot et al,/i>. 1996, in Spencer and Hampton 2005). Management Notes for this Location:
The problem associated with the illegal movement of feral species by private individuals is a growing concern to agricultural and wildlife agencies, and has been recognized for several decades (Caley 1997, Pavlov 1998 in Spencer and Hampton 2005). The detection of deliberate translocations may allow for better control (policing) of this highly destructive and invasive species (Spencer and Hampton 2005).
Semi-arid grazing systems in Australia are characterized by low and erratic rainfall, high summer temperatures and an evaporation rate that exceeds rainfall (Robertson 1987, in Dexter 2003). In these environments, the rate of change in herbivore abundance is heavily dependent upon prevailing vegetation biomass (Bayliss 1985, in Dexter 2003), which is in turn largely dependent on unpredictable rainfall fluctuations (Noy-Meir 1973, in Dexter 2003). In the case of feral pigs in the semi-arid rangelands of Australia, prevailing environmental conditions influence population dynamics through their effect on mortality rate rather than fecundity (Choquenot 1998, in Dexter 2003). Risk of spread of foot and mouth disease should be calculated by considering criteria such as proximity to ports, feral pig density and the likelihood of detection. To this could be added seasonal conditions with good conditions increasing an areas risk ranking and poor seasonal conditions lowering an area's risk ranking. Total pig eradication may not be practical on a regional or local scale ( Dexter 2003). Impacts:
Habitat alteration: Fleay’s Barred-frog (Mixophyes fleayi) is listed as 'Endangered (EN)' in the IUCN Red List of Threatened Species. Endemic to Australia it occurs in wet forests from the Conondale Range in south-east Queensland, south to Yabbra Scrub in north-east New South Wales. While the specific reason for its decline is not known large areas of its habitat are being degraded and altered due to urban encroachment, forest logging, trampling and rooting by pigs (Sus scrofa) and domestic stock; and the invasion of alien invasive weeds like mistflower (Ageratina riparia) and crofton weed (Ageratina adenophora). The Chytrid fungus (Batrachochytrium dendrobatidis) has been identified as the cause of illness and death in some populations (Hines et al 2004).
Habitat alteration: The Southern Gastric Brooding Frog (Rheobatrachus silus) is listed as 'Extinct (EX)' in the IUCN Red List of Threatened Species. Endemic to Australia it occured in the Blackall and Conondale Ranges in south-east Queensland inhabiting streams and catchments of the Mary, Stanley and Mooloolah Rivers. It has not been recorded in the wild since 1981. The reasons for its decline are unknown; the Chytrid fungus (Batrachochytrium dendrobatidis) is suspected to have caused declines in populations. Its habitat is also degraded due to trampling and rooting by pigs (Sus scrofa) and the spread of the alien mistflower (Ageratina riparia) (Meyer et al 2004)
Habitat alteration: The Mount Glorious Day Frog (Taudactylus diurnus) is listed as 'Extinct (EX)' in the IUCN Red List of Threatened Species. An Australian endemic, it occurred in disjunctive populations in three sub-coastal mountain ranges (Blackall, Conondale, and D’Aguilar Ranges) in the south-east Queensland region from Coonoon Gibber Creek in the north to Mount Glorious in the south. It has not been recorded in the wild since 1979. The reasons for its decline are unknown; the Chytrid fungus (Batrachochytrium dendrobatidis) is suspected to have caused declines in populations. Its habitat is also degraded due to trampling and rooting by pigs (Sus scrofa) and the spread of the alien mistflower (Ageratina riparia); Lantana (Lantana camara) and the alien grass Baccharis halimifilia. Frog populations were absent where pigs had caused damage and where alien plants had invaded (Hero et al 2004). Last Modified: 24/07/2006 3:28:50 p.m.
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