In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.
|EPBC Act Listing Status||Listed as Endangered|
|Recovery Plan Decision||
Recovery Plan required, this species had a recovery plan in force at the time the legislation provided for the Minister to decide whether or not to have a recovery plan (19/2/2007).
|Adopted/Made Recovery Plans||
Threatened Tasmanian Eagles Recovery Plan 2006-2010 (Australian Government Department of the Environment and Water Resources (AGDEW), 2006) [Recovery Plan].
|Policy Statements and Guidelines||
Survey Guidelines for Australia's Threatened Birds. EPBC Act survey guidelines 6.2 (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2010l) [Admin Guideline].
Federal Register of
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument].
Documents and Websites
|State Listing Status||
|Non-statutory Listing Status||
|Scientific name||Aquila audax fleayi |
|Infraspecies author||Condon & Amadon, 1954|
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
CITES: Listed at the species level under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
Scientific name: Aquila audax fleayi.
Common name: Wedge-tailed Eagle (Tasmanian).
The Wedge-tailed Eagle (Tasmanian) was first recognised as a distinct subspecies in the early 1950s (Condon & Amadon 1954). The distinction was on the basis of plumage differences between Tasmanian and mainland birds, i.e. Tasmanian birds (at least in juvenile or immature plumage) have buffy-white, pale buff or cream colouration on the crown, nape and shoulder, in contrast to the buff, golden-brown or rufous colouration in mainland birds (Condon & Amadon 1954; Fleay 1952; Marchant & Higgins 1993). Furthermore, adult birds in Tasmania are said to be capable of developing 'golden' or 'russet' patches on the nape, hindneck and upper wings (Meredith 1990). Tasmanian birds are also claimed to be larger (Fleay 1952), and to have larger talons (Condon & Amadon 1954), than their mainland congeners.
Some doubt exists as to the diagnostic nature of these characters, e.g. individuals with paler plumage do occur on the mainland, albeit less frequently (Olsen 2005). Investigations of size differences between Tasmanian and mainland birds have proved inconclusive (Condon & Amadon 1954; Marchant & Higgins 1993; Olsen 2005). Even so, there is thought to be little movement of birds between mainland and Tasmanian populations (Garnett & Crowley 2000; Marchant & Higgins 1993), and preliminary DNA studies indicate that the Tasmanian population may have been genetically isolated from the mainland population for 8000 - 10 000 years (Bell & Mooney 1998). More recently, genetic research has shown that the subspecies is a very recent arrival to Tasmania, and possibly established there 200-1000 years ago (Burridge et al. 2013).
The Wedge-tailed Eagle (Tasmanian) is a large bird that measures 100 to 110 cm in length, with a wingspan of 1.9 to 2.3 m, and a mass of 3.5 to 5.5 kg. Females are larger than males; they have a longer body, a much larger bill, and are about 15% heavier (Bell & Mooney 1998).
The Wedge-tailed Eagle (Tasmanian) has long wings with deeply notched tips, very strong legs and talons, and feathering down to the feet. Adult birds (especially males) are a dark sooty-brown colour. They have reddish-gold colouring on the nape, hindneck and upperwing, and pale silver at the bases of the primary feathers, but this silver colouration is visible only on the underwing (Bell & Mooney 1998; Gaffney & Mooney 1992; Meredith 1990). Adult eagles from Tasmania rarely attain the almost black plumage that may be observed in old individuals on the mainland (Meredith 1990). Juvenile birds from Tasmania are a tawny brown colour at fledging (i.e. when they depart the nest), with 'blonde' (i.e. pale buff, buffish-white or cream) markings on the upperparts and dark flight and tail feathers (Gaffney & Mooney 1992; Marchant & Higgins 1993). The plumage darkens with each successive moult (Bell & Mooney 1998).
The Wedge-tailed Eagle (Tasmanian) usually occurs singly, in pairs or in family groups (Bell & Mooney 1998). On the mainland, large groups sometimes gather. The Wedge-tailed Eagle has also been observed to hunt co-operatively in pairs, less often in groups of up to 15 (Marchant & Higgins 1993).
The Wedge-tailed Eagle (Tasmanian) is found only in Tasmania and nearby islands. The subspecies is widespread on mainland Tasmania, where it occurs in both coastal and inland regions, including the central highlands. It also occurs on the larger offshore islands including Flinders Island, Three Hummock Island, Schouten Island, Maria Island and Bruny Island. Breeding has been recorded throughout much of the range, including on Flinders Island (Bell & Mooney 1998; Gaffney & Mooney 1992; Green 1989; Mooney 1984, 1988a; Thomas 1979).
The Wedge-tailed Eagle is also an occasional visitor to King Island (Thomas 1979; Green 1989), but the subspecific status of these birds has yet to be determined (Garnett & Crowley 2000).
The extent of occurrence is estimated at 70 000 km². This estimate, which is based on published maps of the distribution, is considered to be of high reliability. The extent of occurrence is known to be stable at present, and appears to have undergone little or no change (based on the data available) since the arrival of Europeans (Garnett & Crowley 2000).
The area of occupancy is estimated at 220 km². This estimate, which is based on the number of 1 km² grid squares that the subspecies is believed to occur in at the time when its population is most constrained. The area of occupancy is known to be stable at present, and the estimated size is considered to be of high reliability (Garnett & Crowley 2000; Olsen 2006, pers. comm.), and appears to have undergone little or no change (based on the data available) since the arrival of Europeans (Garnett & Crowley 2000).
The distribution of the Wedge-tailed Eagle (Tasmanian) is naturally fragmented. This is because the eagles occupy very large home ranges and have territories that are very widely dispersed. For example, the estimated density of territories ranges from a maximum of one pair per 20-30 km² in a mosaic of dry sclerophyll forest and fertile open habitat in the lowlands of eastern and northern Tasmania, to a minimum of one pair per 1200 km² in the highlands of western and south-western Tasmania (Bell & Mooney 1998).
At the species level, small numbers of the Wedge-tailed Eagle are held at nine institutions within Australia (ISIS 2005). It is not known what proportion of the birds held in these institutions, if any, are of the Tasmanian subspecies.
Some Wedge-tailed Eagles (Tasmanian) are held for rehabilitation by private operators (Olsen 2006, pers. comm.).
The Wedge-tailed Eagle (Tasmanian) has been reasonably well surveyed:
- Surveys of breeding success were conducted by the Parks and Wildlife Service, Tasmania between 1983 and 1989, and in 1989, 1992, 1993, 1994 and 1997 (Bell & Mooney 1998). These included a Tasmania-wide survey of breeding success in 1988. The results of this survey were used to formulate a series of recommendations for the protection of nest sites. These recommendations were published in Mooney and Holdsworth (1991).
- A large number of pre-logging searches have been conducted since the publication of the original recovery plan in 1992 (Bell & Mooney 1998).
The total population size of the Wedge-tailed Eagle (Tasmania) is estimated at less than 1 000 birds. This includes an adult population that is likely to number less than 440 individuals. These estimates were derived from the estimated number of nesting territories in Tasmania (220), and the likely minimum mortality rates for juveniles (50%), other immature birds (30%) and adults (5%) (Bell & Mooney 1998).
Garnett and Crowley (2000) estimated, based on information in Bell and Mooney (1998), the total population size of the the Wedge-tailed Eagle (Tasmania) to be 440 breeding birds. They consider this estimate to be of medium reliability.
The Wedge-tailed Eagle (Tasmanian) occurs as a single, contiguous population (Garnett & Crowley 2000; Olsen 2006, pers. comm.).
The Wedge-tailed Eagle (Tasmanian) population is likely to be decreasing in size (Garnett & Crowley 2000). Road counts undertaken between 1987 and 1997 indicate that the population is either stable or slowly decreasing. Critically, the proportion of juvenile birds within the population appears to be decreasing due to a lack of recruitment (Bell & Mooney 1998). Importantly, any further decline in the rate of recruitment (and, subsequently, in population size) may not become apparent for some years, as adult Wedge-tailed Eagles (Tasmanian) are long-lived (probably up to 20-25 years in the wild) and suffer low mortality rates (approximately 5% per annum) (Bell & Mooney 1998; Gaffney & Mooney 1992).
No populations have been identified as being of special importance to the survival of the species. The lack of data on population sizes makes it impossible to speculate upon the possible importance of individual populations.
The Wedge-tailed Eagle (Tasmanian) is not known to undergo extreme natural fluctuations in population size, extent of occurrence or area of occupancy.
The generation length of the Wedge-tailed Eagle (Tasmanian) is estimated at 15 years. However, this estimate is considered to be of low reliability due to a lack of knowledge about the life history of the subspecies (Garnett & Crowley 2000).
There are no published records of cross-breeding between the Tasmanian and mainland A. a. audax subspecies of Wedge-tailed Eagle, or between the Wedge-tailed Eagle (Tasmanian) and any other species.
It is estimated that approximately 20% of Wedge-tailed Eagle (Tasmanian) territories occur within designated reserves (Bell & Mooney 1998).
The Atlas of Australian Birds records the Wedge-tailed Eagle (Tasmanian) in 40 conservation reserves since 1998. Most records are from South Bruny National Park, Southwest Conservation Area, Cradle Mountain-Lake St Clair National Park, Dogs Head Hill Forest Reserve, Maria Island National Park, Waterhouse Conservation Area, Arthur-Pieman Conservation Area, Franklin-Gordon Wild Rivers National Park, Central Plateau Conservation Area, Dennes Hill Nature Reserve, and Lime Bay State Reserve (Atlas of Australian Birds, unpublished data held on sightings and surveys database).
The Wedge-tailed Eagle (Tasmanian) inhabits coastal, lowland and highland regions. It has been recorded in a wide variety of habitats including dry sclerophyll forest, temperate rainforest, sub-alpine forest, dry woodland, coastal heathland, small wetlands, riparian vegetation, sedgeland, grassland and farmland. However, breeding is restricted to a range of old-growth native forests, especially those dominated by Eucalyptus species (Bell & Mooney 1998; Gaffney & Mooney 1992; Marchant & Higgins 1993; Mooney & Holdsworth 1991; Thomas 1979).
The Wedge-tailed Eagle (Tasmanian) nests in a range of old-growth native forests, from almost pure rainforest to isolated eucalypts in Acacia forest. However, the majority of nests occur in forests that are dominated by eucalypts. Forest habitats used by the eagle for nesting usually have a closed canopy. Most nests are located in multi-aged communities in which most of the trees present are classified as old-growth. More than 50% of known nests occur in tall open forest above an open or closed understorey (Bell & Mooney 1998; Brown & Mooney 1996; Gaffney & Mooney 1992; Mooney & Holdsworth 1991). The nest is almost always built in an emergent tree that is among the tallest and broadest of those available at a nest site. Nests are usually located in trees that are situated on sloping ground, at an aspect that offers protection from the prevailing winds (e.g. on the leeward side of a ridge, and on the lower part of the slope, so that the top of the tree is below the ground level at the top of the ridge) (Mooney 1988a; Mooney & Holdsworth 1991). The Wedge-tailed Eagle (Tasmanian) will not nest in areas that have high human densities (Bell & Mooney 1998).
The Wedge-tailed Eagle (Tasmanian) forages in open areas. It has been recorded hunting over most types of Tasmanian terrestrial habitat including coastal heath, dry woodland, temperate rainforest, dwarf coniferous forest, sub-alpine forest, grassland and cleared land. The subspecies is also capable of hunting over snowfields, although forests are the preferred foraging habitat (Gaffney & Mooney 1992).
No specific information is available on the ages of sexual maturity, life expectancy or natural mortality in the Wedge-tailed Eagle (Tasmanian), but they are likely to be similar to the species as a whole.
At the species level, the Wedge-tailed Eagle is capable of breeding at 3-5 years of age, although most birds are not recruited into the breeding population until they reach four years or older (Marchant & Higgins 1993; Olsen 2005). The species is long-lived. In the wild, they probably live to 20-25 years of age (Gaffney & Mooney 1992), but they are capable of surviving much longer in captivity. For example, one captive bird lived to 40 years of age, and died when a bone became embedded in its throat, rather than from old age (Olsen 2005).
The Wedge-tailed Eagle breeds in solitary and monogamous pairs that, barring the death of one member, appear mostly to pair for life (Bell & Mooney 1998; Marchant & Higgins 1993).
The Wedge-tailed Eagle (Tasmanian) breeds from late winter to summer, with eggs laid in a narrow window from late August to early September (Gaffney & Mooney 1992; Bell & Mooney 1998). It builds a large nest (up to 2.8 m in diameter) that consists of an accumulation of large dead sticks, with a shallow depression lined with fresh sprigs and green eucalypt leaves (Bell & Mooney 1998; Gaffney & Mooney 1992; Birds Australia, unpublished data). Nests are almost always situated in large eucalypts (mainly E. viminalis, E. delegatensis, E. ovata, E. regnans and E. globulus) (Birds Australia, pers. comm.; Mooney 1988a). Breeding territories can contain several lined nests (and unlined), but usually one is favoured over the others, and will be re-used each year until breeding fails (Bell & Mooney 1998; Mooney 1988a). The use of nest sites is traditional, and the same site may be used for up to 50 years (Bell & Mooney 1998).
The female usually lays one egg, but two eggs may be laid on rare occasions (Bell & Mooney 1998). No specific information is available on the appearance of the eggs, the duration of the incubation period or the role of the sexes in incubation, but these characters are said to be similar to those described for the species as a whole (P. Olsen 2006, pers. comm.). The nestlings of the Wedge-tailed Eagle (Tasmanian) are fed by both parents, and can remain in the nest for up to 90 days. The young remain near the nest for several weeks after fledging (i.e. departing the nest). They depend on their parents for food for at least three months after leaving the nest, and may occasionally accompany their parents until the next breeding season (Bell & Mooney 1998).
At the species level, the eggs of the Wedge-tailed eagle are dull white to buff in colour and are sparsely marked with spots or blotches that vary in colour from purple to reddish-brown (Cupper & Cupper 1981; Marchant & Higgins 1993). The eggs are incubated by both sexes for a period of 42-48 days (Marchant & Higgins 1993).
The breeding success of the Wedge-tailed Eagle (Tasmanian) is thought to be declining. It is estimated that, of the estimated 220 adult pairs, 95 breed successfully (i.e. rear at least one young) each year (Bell & Mooney 1998). During studies undertaken in 1989, 53% of breeding territories in which the active nest or all nests were known were believed to have reared young successfully. The successful territories reared an average of 1.07 young each (Mooney & Holdsworth 1991). Fratricide (the killing of siblings) has been recorded in mainland populations of the Wedge-tailed Eagle (e.g. Cupper & Cupper 1981), but has not been observed in Tasmania (Bell & Mooney 1998).
The rate of population recruitment in the Wedge-tailed Eagle (Tasmanian) is low, e.g. it can take up to six months, following the loss of one member of a pair, for a new pair to be formed (Bell & Mooney 1998). The rate of recruitment is likely to have declined due to the mortality associated with threatening processes. Furthermore, the impact of threatening processes upon the rate of recruitment has probably been amplified by the nature of the associated mortality, and the segments of the population that are affected. For example, the mortality rate in the Wedge-tailed Eagle due to natural causes is likely to be approximately 50% in juveniles, 30% in other immature birds and 5% in adults (Bell & Mooney 1998). However, the mortality associated with threatening processes is comparatively random, and it is possible that the deaths of an unnaturally high number of adult birds may have reduced the mean age of the breeding population. This in turn may have contributed to the decline in breeding success, by enabling less experienced and (presumably) less competent birds to attempt to breed (Bell & Mooney 1998). Furthermore, the mortality caused by some threatening processes may be greater in some population classes that are crucial to maintaining the rate of recruitment. For example, the mortality rate due to vehicle collisions may be greater in adult females than in the rest of the population due to their greater reluctance to flush (fly-away from) from carrion. Adult females and immature birds are potentially at greater risk of being shot by farmers: adult females, because of their large size, may be more inclined to take large prey such as lambs; and both adult females and immature birds are more inclined to feed upon carrion (including of domestic stock) than adult males (Bell & Mooney 1998; Mooney & Hunt 1983). In addition, the habit of immature birds of feeding heavily on carrion (Bell & Mooney 1998) would also increase the risk of secondary poisoning.
The Wedge-tailed Eagle is carnivorous, and feeds on both live prey and carrion. It feeds mainly on rabbits and hares, but a wide variety of vertebrate prey is consumed, including reptiles, birds and mammals (Marchant & Higgins 1993). It is capable of killing prey several times their own body weight, though most prey items taken are much smaller (approximately 25% or less of the eagle's mass) (Bell & Mooney 1998).
In rural Tasmania, the diet of the Wedge-tailed Eagle (Tasmanian) consists of rabbits, hares and cats (which comprise approximately 45% of items consumed); wallabies, possums, echidnas and wombats (approximately 30% of items consumed); birds (approximately 10% of items consumed); sheep and goats (approximately 7.5% of items consumed); and reptiles (approximately 5% of items consumed) (the remaining 2.5% of the diet is composed of other items) (Gaffney & Mooney 1992). Carrion is a major source of food, especially for immature birds (which lack hunting experience), although adults will also feed heavily on carrion during winter (Bell & Mooney 1998).
The Wedge-tailed Eagle (Tasmanian) captures most of its live prey by sallying. This typically involves a bird launching itself from a perch and then attacking prey on the ground or, less frequently, in flight, but can include other variations such as diving at prey from high altitudes whilst in flight, or slow quartering (( methodical search of an area) whilst flying at 10-20 m above the ground. Prey can also be captured by means other than sallying, e.g. eagles hunt for Brush-tailed Possums Trichosurus vulpecula by flying slowly through the canopy in search of shallow hollows in trees which, upon discovery, are examined from a perch (Bell & Mooney 1998). Hunting usually takes place during the day. Prey is usually eaten where it is captured, except during the breeding season when much of the food is taken back to the nest and is fed to the young (Bell & Mooney 1998).
Little information is available on the movements of the Wedge-tailed Eagle (Tasmanian). Adult birds remain resident on their territories throughout the year, although patterns of habitat usage within territories appear to be subject to seasonal variation (Bell & Mooney 1998). Juvenile birds disperse widely after abandoning their parents (Mooney 1988a). There have been no records of eagles undertaking movements across Bass Strait (Marchant & Higgins 1993), and they are said to be reluctant to cross large stretches of open water (Bell & Mooney 1998). However, eagles have been recorded on islands in Bass Strait: breeding has been recorded on Flinders Island in the Furneaux Group (Mooney 1984, 1988a; Thomas 1979), the species is a rare visitor to King Island (Green 1989), and a single bird (subspecies unknown) was sighted over Curtis Island (Brothers 1985).
No specific figures are available on the size of home ranges occupied the Wedge-tailed Eagle (Tasmanian), but they are said to be very large (Bell & Mooney 1998).
Pairs defend a territory. A single territory will usually contain two or three nests (Mooney 1998a), but some may have more. Only one is active at any one season, the others may be used as roosts or to feed on and some are usually in a state of disrepair (Bell & Mooney 1998). The nests within a territory are usually spaced about 200 m apart, but they can be separated by distances of more than 1 km in areas where habitat is patchy or restricted (Bell & Mooney 1998).
Where suitable habitat is available, territories tend to be evenly dispersed. As a result, the subspecies is only recorded nesting in low densities. The estimated densities of Wedge-tailed Eagle (Tasmanian) territories range from a maximum of one pair per 20-30 km² in a mosaic of dry sclerophyll forest and fertile open habitat in the lowlands of eastern and northern Tasmania, to a minimum of one pair per 1200 km&3178; in the highlands of western and south-western Tasmania. It is estimated that a total of 220 territories occur in Tasmania (Bell & Mooney 1998).
Territories appear to be occupied throughout the year (e.g. during the non-breeding season birds often visit the breeding area to perch or eat, or to renovate nests) (Mooney 1988a). Birds display a traditional, long-term attachment to their territories, or, more particularly, their nest sites, some of which are known to have been used for more than 50 years (Bell & Mooney 1998).
The Wedge-tailed Eagle (Tasmanian) is detected by sight (i.e. sighting of soaring or perched birds, or nests). Eagles are conspicuous when soaring and when perched on exposed sites, but can be difficult to locate in forest habitat. They are also wary when approached by humans. They are most easily detected at the onset of the breeding season when they engage in bonding, mating and territorial displays, usually whilst in flight (Bell & Mooney 1998; Magrath et al. 2004).
The Wedge-tailed Eagle (Tasmanian) is a large, distinctive bird that, when perched, is unlikely to be mistaken for any other species (Magrath et al. 2004). However, it is possible that soaring birds viewed from the ground (i.e. from below) could be confused with the White-bellied Sea-Eagle Haliaeetus leucogaster, which is also a large raptor with a widespread distribution in Tasmania (Marchant & Higgins 1993).
The nest of the Wedge-tailed Eagle (Tasmanian) is large and relatively conspicuous, but could be confused with the nest of the White-bellied Sea-Eagle Haliaeetus leucogaster (Olsen 2006, pers. comm.).
The major threats to the Wedge-tailed Eagle (Tasmanian) are loss of nesting habitat and disturbance of nesting birds and, to a lesser degree, persecution by humans (Bell & Mooney 1998; Gaffney & Mooney 1992; Mooney 1997).
The nesting habitat of the Wedge-tailed Eagle (Tasmanian) (i.e. old-growth forest dominated by Eucalyptus species) has been lost through clearance for agriculture, forestry and housing (Bell & Moloney 1998; Gaffney & Mooney 1992). In Tasmania, it has been estimated that a combined total of at least 40% of forests (including dry, wet and swamp forests) and dry woodlands have been cleared since the time of settlement (Gaffney & Mooney 1992). Furthermore, contemporary logging operations often leave nest-trees isolated or in small patches of remnant habitat. Such sites are very rarely re-occupied by eagles for breeding purposes, possibly due to the increased exposure of nest sites, and to the reduced availability or lack of alternative nest sites in the surrounding area (Garnett & Crowley 2000; Mooney 1988a, 1997). Given that 80% of known nests occur on private land or in State Forest, there is potential for a large proportion of the breeding population to be affected by forest clearance (Bell & Mooney 1998).
The breeding success of the Wedge-tailed Eagle (Tasmanian) is thought to be declining due to the increased disturbance of nesting pairs. The eagle is described as an 'extremely shy' nester, and pairs readily desert nests if exposed to elevated levels of disturbance such as that associated with logging operations, roadworks and development/construction, and less obvious activities such as recreation, tourism and research (Bell & Mooney 1998; Gaffney & Mooney 1992; Mooney 1997; Mooney & Holdsworth 1991). The ongoing development of both rural and residential areas is considered to be the most important source of disturbance, as the disturbance is, in all likelihood, irreversible (Bell & Mooney 1998). However, intensive logging is also of concern due to its increased spread in recent years, and because intensive post-winter logging operations usually coincide with the incubation period of the eagle, a time when breeding pairs are highly sensitive to disturbance (Mooney 1988a). Given that 80% of known Wedge-tailed Eagle (Tasmanian) nests occur on private land or in State Forest, there is potential for a large proportion of the breeding population to be exposed to and affected by disturbance (Bell & Mooney 1998).
The Wedge-tailed Eagle (Tasmanian) is subject to ongoing conflict with livestock owners and other parts of the public. Wedge-tailed Eagles, and especially immature birds, feed on carrion, including that of domestic livestock. Research on the predation of domestic livestock by Wedge-tailed Eagles has shown that very few live animals are taken, and of those that are taken, they are typically sick or dying. Despite this, a misunderstanding of this fact has led to the implementation of shooting, trapping and poisoning programs (Bell & Mooney 1998; Mooney 1988a, 1997). The shooting of birds by vandals, and the collection of small numbers of birds for the small and illegal market for mounted specimens, are additional sources of mortality (Bell & Mooney 1998). It is estimated that a minimum of 5% of adult and 35% of immature Wedge-tailed Eagles (Tasmanian) are killed each year as a result of the ongoing conflict (Bell & Mooney 1998; Mooney & Holdsworth 1991).
There are several additional causes of mortality which, in concert with primary factors listed above, increase the threat of extinction to this species. These include non-target and secondary poisoning, collisions with vehicles, collisions with overhead wires and fences, collisions with wind turbines, and electrocution (Bell & Mooney 1998; Mooney 1997; P. Olsen 2006, pers. comm.). Its habit of feeding on carrion exposes the Wedge-tailed Eagle (Tasmanian) to secondary poisoning (e.g. via ingestion of rabbits laced with pindone) and, when feeding on road-kill, to collisions with vehicles (Martin et al. 1994; Bell & Mooney 1998; Mooney 1997). Non-target poisoning can occur when birds ingest baits intended for dogs, ravens Corvus or Tasmanian Devils Sarcophilus harrissi (Bell & Mooney 1998; Mooney 1997). Electrocution results from contact with power lines and installations, which may be used as perches when hunting (Bell & Mooney 1998; Mooney 1997). The frequency of collisions with vehicles, wires and fences, and of electrocution, will presumably increase as rural and residential areas become more developed (Bell & Mooney 1998). Collision with wind turbines has been identified as a potential threat to the Wedge-tailed Eagle (Tasmanian). Raptors are thought to be at higher risk of collission due to their tendancy to make flights in the swept area (WBPWF FR 2007a). However, a number of studies have found that the risk of collission is extremely low, with birds avoiding the swept area of the turbine blades in over 98% of cases (Biosis Research 2007; Smales &: Muir 2005; WBPWF FR 2007b).
The loss of suitable habitat has also increased conflict between the Wedge-tailed Eagle (Tasmanian) and the White-bellied Sea-Eagle Haliaeetus leucogaster for nest sites, and this is known to have caused breeding failures in both species (Spencer & Lynch 2005).
The Wedge-tailed Eagle (Tasmanian) is unlikely to be severely affected by any 'catastrophic' threats (i.e. potentially catastrophic threats such as drought or wildfire were not identified as a risk to the subspecies in either of the published recovery plans (Bell & Mooney 1998; Gaffney & Mooney 1992).
The long-term survival of the Wedge-tailed Eagle (Tasmanian) is dependent upon the maintenance and conservation of nesting habitat, and the alleviation of threatening processes (e.g. disturbance, human-induced mortality) and their direct and indirect effects on the population (Bell & Mooney 1998).
The following recovery measures were implemented prior to the publication of the 1998-2003 recovery plan (Bell & Mooney 1998, available at http://www.environment.gov.au/biodiversity/threatened/publications/recovery/wedge-tail/index.html):
- Publication of recommendations for the protection and conservation of nest sites (see Mooney 1988a, Mooney & Holdsworth 1991), including incorperating the protocols and prescriptions into forest management practices.
- Regular surveys of breeding success.
- Publication of the first recovery plan (Gaffney & Mooney 1992), and formation of a recovery team to implement the plan.
- Pre-logging searches for nests and nest sites.
- Review of the value of nest site protection in ameliorating the effects of forestry operations on the Wedge-tailed Eagle (Tasmanian).
- Development of a to predict the likely location of nesting habitat (see Brown & Mooney 1996).
- Preliminary studies to compare the genetic variation in the Tasmanian and mainland A. a. audax subspecies.
- Establishment of an electronic database to record details about nesting pairs and nesting habitat.
- Public education to increase their awareness of the Wedge-tailed Eagle (Tasmanian) and its situation, including distributing a brochure ('Eagles on the Farm') to more than 14 000 properties in rural Tasmania.
The following recovery actions were proposed in the most recent published recovery plan (Bell & Mooney 1998, available at http://www.environment.gov.au/biodiversity/threatened/publications/recovery/wedge-tail/index.html):
- Locate nests on private land and in State Forests by: (1) developing predictive models of nesting habitat; (2) searching prioritised areas of forest for nests; (3) trapping, radio-tagging and tracking breeding birds to their nests; and (4) searching for nests in proposed logging coupes.
- Protect nesting habitat on private land and in State Forests by: (1) liaising with private landowners and informing land management practices; and (2) assessing the security of reserves with eagle nests.
- Monitor breeding success and abundance by: (1) maintaining a nest site register; (2) conducting biennial surveys of breeding success; (3) conducting road counts to assess abundance; (4) updating management prescriptions for nesting habitat; and (5) monitoring reports of mortality.
- Promote the conservation of the subspecies to land owners and managers.
- Continued assesment and review of the recovery effort by the Parks and Wildlife Service, Tasmania.
There has been only one published major study on the Wedge-tailed Eagle (Tasmanian) by Mooney and Holdsworth (1991).
A Recovery Plan: Management Phase was prepared by Gaffney and Mooney (1992), and a Recovery Plan was prepared by Bell and Mooney (1998).
A new recovery plan is currently in preparation (DEH 2006).
The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.
|Threat Class||Threatening Species||References|
|Agriculture and Aquaculture:Agriculture and Aquaculture:Habitat modification and disturbance due to fencing||Recovery Plan for the Wedge-tailed Eagle - 1998-2003 (Bell, P. & N. Mooney, 1998) [State Recovery Plan].|
|Agriculture and Aquaculture:Agriculture and Aquaculture:Land clearing, habitat fragmentation and/or habitat degradation||
Recovery Plan for the Wedge-tailed Eagle - 1998-2003 (Bell, P. & N. Mooney, 1998) [State Recovery Plan].
The Action Plan for Australian Birds 2000 (Garnett, S.T. & G.M. Crowley, 2000) [Cwlth Action Plan].
Commonwealth Listing Advice on Land clearance (Threatened Species Scientific Committee, 2001w) [Listing Advice].
|Biological Resource Use:Hunting and Collecting Terrestrial Animals:illegal control||Recovery Plan for the Wedge-tailed Eagle - 1998-2003 (Bell, P. & N. Mooney, 1998) [State Recovery Plan].|
|Biological Resource Use:Logging and Wood Harvesting:Habitat disturbance due to foresty activities||Recovery Plan for the Wedge-tailed Eagle - 1998-2003 (Bell, P. & N. Mooney, 1998) [State Recovery Plan].|
|Biological Resource Use:Logging and Wood Harvesting:Habitat loss, modification and degradation due to timber harvesting|
|Human Intrusions and Disturbance:Recreational Activities:shooting|
|Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Presence of pathogens and resulting disease|
|Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development|
|Species Stresses:Indirect Species Effects:Low numbers of individuals|
|Species Stresses:Indirect Species Effects:Poor recruitment (regeneration) and declining population numbers|
|Transportation and Service Corridors:Roads and Railroads:Vehicle related mortality|
|Transportation and Service Corridors:Utility and Service Lines:Collision with human infrastructure|
|Transportation and Service Corridors:Utility and Service Lines:Powerline easement maintenance and construction; mortality due to collision with powerlines|
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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.
Citation: Department of the Environment (2014). Aquila audax fleayi in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 14 Mar 2014 04:04:20 +1100.