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 Vulnerable|
|Listing and Conservation Advices||
Commonwealth Conservation Advice for Egernia rugosa (Yakka Skink) (Threatened Species Scientific Committee (TSSC), 2014bw) [Conservation Advice].
|Recovery Plan Decision||
Recovery Plan not required, the approved conservation advice for the species provides sufficient direction to implement priority actions and mitigate against key threats (29/04/2014).
|Adopted/Made Recovery Plans|
|Policy Statements and Guidelines||
Draft Referral guidelines for the nationally listed Brigalow Belt reptiles (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011e) [Admin Guideline].
Survey guidelines for Australia's threatened reptiles. EPBC Act survey guidelines 6.6 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011m) [Admin Guideline].
Yakka Skink; Egernia rugosa; National Threatened Species Day Information Sheet (Threatened Species Network (TSN), 2008a) [Information Sheet].
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||Egernia rugosa |
|Species author||De Vis,1888|
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
Scientific name: Egernia rugosa
Common name: Yakka Skink
The Yakka Skink was described by Cogger and colleagues (1983) and was previously referred to as Egernia dorsalis (Mitchell 1950). This species is placed within Egernia Subgenus Major (Chapple 2003).
The Yakka Skink is a pale fawn reptile growing to 40 cm. It has a broad dark brown to black stripe from nape to tail bordered on either side by a narrow, pale fawn back/side stripe. Dark brown to pale brown to reddish-brown scales on the flanks form a faintly variegated orange-brown pattern. The throat is cream-yellow in colour, with blackish flecks/spots, and the chest and abdomen are yellow-orange (Cogger 2000). This skink is often described as robust and around the same size as a Blue Tongue Lizard (Tiliqua scincoides) making it one of the largest skinks in sub-humid to semi-arid eastern Queensland (TSN 2008a).
The known distribution of the Yakka Skink extends from the coast to the hinterland of sub-humid to semi-arid eastern Queensland. This vast area covers portions of the Brigalow Belt (North and South), Mulga Lands, South-east Queensland, Einasleigh Uplands, Wet Tropics and Cape York Peninsula Biogeographical Regions. Locations range from the Queensland/New South Wales border to Mungkan Kandju National Park (NP) on Cape York Peninsula, and from Bundaberg and the region west of Gympie to Mariala NP west of Charleville (Brigalow Belt Reptiles Workshop 2010; Cogger 2000; Wilson & Knowles 1988). Specimens in Queensland have been collected from the following (Covacevich et al. 1996a; Mitchell 1950):
- Culgoa Floodplain NP
- 50 km north of Goondiwindi
- 20 km west of St. George
- Alton NP
- Thrushton NP
- Lynrock Station, Surat
- 32 km south-west of Chinchilla
- Chesterton Range NP
- Mariala NP
- Arcadia Valley (via Injune)
- Calladie Road, near Biloela
- Miriam Vale
- 3 km west of Bogantungan
- east of Comet
- Mount Cooper Station
- Rockwood Station
- 19 km south of Helenvale
- Bald Hill Station, 32 km west of Cooktown
- Mount Croll, 18 km north-north-west of Coen on Cape York Peninsula
- locations within 5 km of the confluence of the Archer and Coen Rivers (western edge of Mungkan Kandju NP) on Cape York Peninsula.
The Yakka Skink's distribution is highly fragmented as a large proportion of potential habitat for the species has been cleared throughout the species' range (Brigalow Belt Reptiles Workshop 2010; Queensland DERM 2010).
The Commonwealth environment department considers that an occurrence of important habitat for the Yakka Skink is a surrogate for an ‘important population’ of the species. For a description of important habitat for the Yakka Skink, refer to the Draft referral guidelines for the nationally listed Brigalow Belt reptiles.
The Yakka Skink has been found in the following nature reserves (Brigalow Belt Reptiles Workshop 2010):
- Culgoa Floodplain NP
- Alton NP
- Thrushton NP
- Chesterton Range NP
- Mariala NP
- Mungkan Kandju NP.
The Yakka Skink is known to occur in open dry sclerophyll forest, woodland and scrub (Brigalow Belt Reptiles Workshop 2010; Cogger 2000; Wilson & Knowles 1988). The core habitat of this species is within the Mulga Lands and Brigalow Belt South Bioregions (TSN 2008b).
It occurs in a wide variety of vegetation types within Queensland Regional Ecosystem Land Zones (LZ) (Brigalow Belt Reptiles Workshop 2010):
- LZ 3 - Alluvium (river and creek flats)
- LZ 4 - Clay plains not associated with current alluvium
- LZ 5 - Old loamy and sandy plains
- LZ 7 - Ironstone jump-ups
- LZ 9 - Undulating country on fine-grained sedimentary rocks
- LZ 10 - Sandstone ranges.
Whilst LZ 8 (basalt plains and hills) is not considered to be representative of core habitat for the Yakka Skink, the species may still occur in this land zone. Basalt-derived soils are generally suitable for burrowing, less at risk of water-logging than alluvium and often occur in a topographic mosaic with fine-grained sediments where the skink does occur (Brigalow Belt Reptiles Workshop 2010).
For more information on Queensland Regional Ecosystems, please visit the Queensland Department of Environment and Resource Management website at http://www.derm.qld.gov.au/wildlife-ecosystems/biodiversity/regional_ecosystems/.
Common vegetation types
Common woodland and open forest types include (Brigalow Belt Reptiles Workshop 2010; QLD DERM 2010):
- Brigalow (Acacia harpophylla)
- Mulga (A. aneura)
- Bendee (A. catenulata)
- Lancewood (A. shirleyi)
- Belah (Casuarina cristata)
- Poplar Box (Eucalyptus populnea)
- Ironbark (Eucalyptus spp.)
- White Cypress Pine (Callitris glaucophylla).
Chapple (2003) observed the species in ecotonal forest in rainforest and wet/dry sclerophyll forest.
The Yakka Skink is commonly found in cavities under and between partly buried rocks, logs or tree stumps, root cavities and abandoned animal burrows (Brigalow Belt Reptiles Workshop 2010; TSN 2008a). The species often takes refuge in large hollow logs and has been known to excavate deep burrow systems, sometimes under dense ground vegetation (Cogger 2000; Ehmann 1992b; Wilson & Knowles 1988). In cleared habitat, this species can persist where there are shelter sites such as raked log piles, deep gullies, tunnel erosion/sinkholes and rabbit warrens. The species has also been found sheltering under sheds and loading ramps (Brigalow Belt Reptiles Workshop 2010; TSN 2008a). This species is not generally found in trees or rocky habitats (Chapple 2003).
Communal latrine sites
Like many other Egernia species, Yakka Skinks defecate in a pile outside burrow entrances (Brigalow Belt Reptiles Workshop 2010; Wilson & Knowles 1988). A colony of Yakka Skinks may use several sites during the year with the occupied burrow identified by scat piles near the entrance (Ehmann 1992b).
Co-occurrence with nationally listed ecological communities
The Yakka Skink is known to occur in the EPBC Act listed Brigalow (Acacia harpophylla dominant and co-dominant) ecological community (Brigalow Belt Reptiles Workshop 2010; Cogger 2000; Wilson & Knowles 1988).
The species is also known to occur in Queensland Regional Ecosystem (RE) 11.3.2 (Brigalow Belt Reptiles Workshop 2010). Weeping Myall (Acacia pendula) can sometimes dominate the distinctly low tree layer in this RE. As such, the species may coincide with the EPBC Act-listed Endangered Weeping Myall Woodlands ecological community in a given patch of RE 11.3.2, depending on whether the vegetation meets the listing criteria for the listed community.
Co-occurrence with the nationally listed Brigalow Scaly-foot (Paradelma orientalis)
The Yakka Skink is known to co-occur with the Brigalow Scaly-foot (Paradelma orientalis), which is listed as Vulnerable under the EPBC Act. The species may co-occur in a range of vegetation types within Queensland Regional Ecosystem Land Zones 3, 4, 5, 7, 9, 10 and possibly 8 (Brigalow Belt Reptiles Workshop 2010).
The Yakka Skink produces live young, with around six per litter (QLD DERM 2010; TSN 2008a).
The Yakka Skink, like other Egernia species, has been described as highly gregarious, with populations occurring primarily as colonies or aggregations. These groups consist of both adults and juveniles of a wide variety of body sizes (Chapple 2003; Osterwalder et al. 2004). The level of this behaviour has only been recorded anecdotally for the Yakka Skink (Chapple 2003).
The Yakka Skink is omnivorous, consuming soft plant materials and fruits and a wide variety of invertebrates (beetles, grasshoppers and spiders) that venture into or near the burrow entrance (TSN 2008a).
The Yakka Skink is active during the morning, and from dusk through the early evening (Brigalow Belt Reptiles Workshop 2010). These skinks exhibit high site-fidelity and are limited in their capacity to disperse from a colony site (Brigalow Belt Reptiles Workshop 2010).
Distinctiveness and detectability
This large skink is unlikely to be mistaken for any other species. It is possible that juveniles could be mistaken for adult tree skinks (Egernia striolata) which occur within the distribution of the Yakka Skink. However, tree skinks have a much more depressed head and body (DSEWPaC 2011m; Brigalow Belt Reptiles Workshop 2010).
Sampling and recording of observed specimens
Potential records of the Yakka Skink should be supported by a good quality colour photograph. These should be forwarded to the Queensland Museum for positive identification and data collation of the record (DSEWPaC 2011m).
Tissue sampling should only be undertaken with appropriate training in tissue preservation, ethics approval and State permits to collect samples. Where possible photo vouchers should include close-up colour shots of the limb areas, and the head, body and tail dorsally, ventrally and laterally. Dead specimens (e.g. roadkills) should be frozen and advice on preservation and lodgement sought from the Queensland Museum (DSEWPaC 2011m; Brigalow Belt Reptiles Workshop 2010).
A habitat assessment is recommended to be undertaken as a preliminary step to designing and undertaking a targeted survey, including:
- Determine the proximity of nearest records to the study area.
- Search relevant databases such as Zoology Data Search (Queensland Museum) and Wildlife Online (Queensland Department of Environment and Resource Management).
- Obtain State vegetation mapping for the study area to determine the extent of suitable habitat including the presence of associated vegetation communities.
- Determine the presence of suitable microhabitat features in the study area.
Targeted surveys to confirm the presence/absence of the Yakka Skink are done by actively searching suitable open-forest, woodland and scrub habitats for potential colony sites and deploying well-shaded Elliott-style trapsclose to burrow entrances (Brigalow Belt Reptiles Workshop 2010).
Searching for burrow systems and communal defecation sites is the most reliable method of detection. Yakka Skink are especially wary and will quickly retreat into their burrows or take shelter if they detect movement or a disturbance in their surrounding environment (Brigalow Belt Reptiles Workshop 2010). The Yakka Skink can be confirmed by Elliott trapping around the burrows (cat food is a reliable bait) (Peck 2010, pers. comm.), by distant observation with binoculars or by shining a torch down burrows at night (Brigalow Belt Reptiles Workshop 2010; DSEWPaC 2011m; Eddie 2010, pers. comm.).
Please note that the use of traps requires State government approval. It is important to ensure that trapped animals, including by-catch, do not suffer injury or death from the effects of high temperatures, dehydration or predation, whilst caught in traps.
Optimal conditions for searching burrows
The species is more likely to be detected when conditions are warm, not too dry and maximum temperatures are greater than 25°C. Optimal survey times for active searching are early morning (two hours either side of dawn) and during the evening on warm nights (Brigalow Belt Reptiles Workshop 2010; DSEWPaC 2011m).
Minimum survey effort
Sufficient time is required to thoroughly search the area by day and to spotlight by night. The minimum survey effort required includes (Brigalow Belt Reptiles Workshop 2010):
- a minimum of three survey days and nights
- at least one replicate survey employing all of the recommended techniques, if the species has not already been detected.
Habitat loss and degradation
The main threat to the Yakka Skink is habitat reduction and degradation. The Yakka Skink occurs in the Brigalow Belt Bioregion, an area of high human impact (Covacevich et al. 1998). Much of this land has been modified through agricultural and urban development (Cogger et al. 1993; McDonald et al. 1991).
Inappropriate roadside management, including road widening and removal of microhabitat, such as rocks, logs, dense leaf litter and fallen bark, threatens the species with habitat loss and degradation. Feral animal impacts include predation by Foxes (Vulpes vulpes) and Feral Cats (Felis catus) and ripping of rabbit warrens (TSN 2008a, 2008b).
Detrimental biological characteristics of the species
The Yakka Skink exhibits high site-fidelity, low fecundity and are long-lived. The combination of these biological factors makes this species susceptible to potential population crashes or even local extinctions given prolonged unfavourable conditions or sudden, large environmental disturbances (Brigalow Belt Reptiles Workshop 2010).
Actions that may improve the conservation status of this species include (EA 1999a, 1999b; TSN 2008a, 2008b):
- Maintaining large, healthy connected patches of suitable habitat.
- Retaining fallen timber and ground cover.
- Coordinating implementation of Fox and Feral Cat control measures (EA 1999a, 1999b).
- Surveying of roadside sites prior to road maintenance, with flagging and protecting of suitable habitats.
- Avoiding grazing disturbance of colonies; fence if necessary.
- Using cool mosaic burn patterns; increase area managed for conservation purposes.
- Notifying the Threatened Species Network of any sightings - take photos of habitat and close-up photos of specimens if possible (the species is secretive, cautious and will quickly take cover if disturbed).
- Development of an appropriate fire management strategy, establishment of an ex situ population and development of identification toolkits suitable for land managers.
- Notifying the Compliance and Enforcement Branch (the Department of Sustainability, Environment, Water, Population and Communities) of any activities which have the potential to significantly impact on the species (TSN 2008a).
Funding through the TSN Community Grants in 200708 was used to address the threat of Fox and Feral Cat predation on a Yakka Skink colony at Myall Park Botanic Gardens (TSN 2008a). The aim of this program was to decrease the number of grazing animals in the area to reduce habitat degradation and to reduce the impact of Foxes and Feral Cats (TSN 2008a).
Recovery planning and implementation
A recovery plan for the Queensland Brigalow Belt Reptiles, including the Yakka Skink, was drafted by WWF-Australia in 2006 (Richardson 2006). The recovery actions outlined in this plan, and in the species profile on the Queensland Department of Environment and Resource Management (Queensland DERM 2010b), are as follows:
- Encourage involvement, provide incentives and adopt a collaborative approach with government agencies, NRM regional bodies, the Indigenous community, key industry stakeholders and local governments to deliver region-specific information and implement sustained, effective recovery actions.
- Identify research priorities: develop and support the implementation of research projects undertaken by tertiary and research institutions.
- Inspect and identify suitable habitat for conservation of the Yakka Skink.
- Identify key threats and develop management guidelines to protect key habitat.
- Maximise the establishment of appropriate reserves to protect Yakka Skink habitat and landscape connectivity over the long term; e.g. on stock route networks, road reserves and private lands.
- Ensure Yakka Skink conservation is incorporated into appropriate land management decisions made by all levels of government and industry.
- Develop and provide land-management guidelines and incentives for landowners to reduce the impact of current land use practices on the species outside reserves, e.g. restricting the use and spread of agricultural weeds, such as Buffel Grass (Cenchurus ciliaris).
- Negotiate management agreements and voluntary conservation agreements with landholders, on whose land the Yakka Skink occurs, in line with the recommended management guidelines.
- Facilitate on-ground projects to manage and protect habitats on a range of land tenures in line with recommended management guidelines, for example, in integrated weed and feral predator management programs.
- Develop community awareness within the species' known range through media campaigns and education material and provide incentives for wider community involvement; e.g. local governments and schools participating in reptile educational programs and adopting a local reptile species as their shire and/or school icon.
- Implement recommended fire management guidelines in property and reserve designs.
- Work with landholders and key stakeholders to undertake monitoring programs on selected sites.
- Monitor and evaluate recovery actions, applying an adaptive management approach.
Mitigation measures or approaches that have been developed for the Yakka Skink are (Brigalow Belt Reptiles Workshop 2010):
- alternative project locations
- avoid clearing/ retain habitat
- design proposed action to avoid habitat disturbance
- establish adequate buffer zones to protect habitat
- implement measures to exclude cattle from habitats
- maintain habitat connectivity across the landscape, e.g., along roadside reserves
- retain shelter habitat features in place
- devise and implement a habitat management plan specific to the Yakka Skink
- implement measures to reduce the risk of invasive and predatory species accessing reptile habitat, e.g. Buffel Grass
- devise and implement an appropriate fire management plan
- devise and implement water management, sediment erosion and pollution control plans.
Management documents for the Yakka Skink include:
- Draft National Recovery Plan for the Queensland Brigalow Belt Reptiles (Richardson 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:Land clearing, habitat fragmentation and/or habitat degradation||
Reptile diversity at risk in the Brigalow Belt, Queensland. Memoirs of the Queensland Museum. 42(2):475-486. (Covacevich, J.A., P.J. Couper & K.R. McDonald, 1998) [Journal].
Egernia rugosa in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006iu) [Internet].
|Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development||Egernia rugosa in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006iu) [Internet].|
Brigalow Belt Reptiles Workshop (2010). Proceedings from the workshop for the nine listed reptiles of the Brigalow Belt bioregions. 18-19 August. Brisbane: Queensland Herbarium.
Chapple, D.G. (2003). Ecology, Life-History, and Behavior in the Australian Scincid Genus Egernia, with Comments on the Evolution of Complex Sociality in Lizards. Herptological Monographs. 17:145-180.
Cogger, H.G. (2000). Reptiles and Amphibians of Australia - 6th edition. Sydney, NSW: Reed New Holland.
Cogger, H.G., E.E. Cameron & H.M. Cogger (1983). Amphibia and Reptilia. In: Walton, D.W., ed. Zoological Catalogue of Australia. 1. Netley, South Australia: Griffin Press Limited.
Covacevich, J.A., P.J. Couper & K.R. McDonald (1996a). Reptiles of Queensland's Brigalow Biogeographic Region: Distributions, Status and Conservation. Page(s) 148. Canberra: Australian Nature Conservation Agency (ANCA).
Covacevich, J.A., P.J. Couper & K.R. McDonald (1998). Reptile diversity at risk in the Brigalow Belt, Queensland. Memoirs of the Queensland Museum. 42(2):475-486.
Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2011m). Survey guidelines for Australia's threatened reptiles. EPBC Act survey guidelines 6.6 . [Online]. Canberra, ACT: DSEWPaC. Available from: http://www.environment.gov.au/epbc/publications/threatened-reptiles.html.
Ehmann, H. (1992b). Reptiles. In: Strahan, R., ed. Encyclopedia of Australian Animals. Sydney: Angus & Robertson.
Environment Australia (EA) (1999a). Threat Abatement Plan for Predation by the European Red Fox. [Online]. Biodiversity Group, Environment Australia. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/foxes08.html.
Environment Australia (EA) (1999b). Threat Abatement Plan for Predation by Feral Cats. [Online]. Biodiversity Group, Environment Australia. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/cats08.html.
McDonald, K.R., J.A. Covacevich, G.J. Ingram & P.J. Couper (1991). The status of frogs and reptiles. In: Ingram, G.J. & R.J. Raven, eds. An Atlas of Queensland's Frogs, Reptiles, Birds and Mammals. Page(s) 338-345. Brisbane: Queensland Museum.
Mitchell, F.J. (1950). The scincid genera Egernia and Tiliqua (Lacertilia). Records of the South Australian Museum. 9 (3):275-308.
Osterwalder, K., A. Klingenbock & R. Shine (2004). Field studies on a social lizard: Home range and social organization in an Australian skink, Egernia major. Austral Ecology. 29:241-249.
Queensland Department of Environment and Resource Management (Queensland DERM) (2010). Wildlife and Ecosystems-Yakka Skink. [Online]. Available from: http://www.derm.qld.gov.au/wildlife-ecosystems/wildlife/az_of_animals/yakka_skink.html.
Richardson, R. (2006). Draft Queensland Brigalow Belt Reptile Recovery Plan 2008 - 2012. [Online]. Report to the Department of the Environment, Water, Heritage and the Arts, Canberra. Brisbane, Queensland: WWF-Australia. Available from: http://www.qmdc.org.au/publications/download/52/fact-sheets-case-studies/reptile-recovery/draft-reptile-recovery-plan.pdf.
Threatened Species Network (TSN) (2008a). Yakka Skink; Egernia rugosa; National Threatened Species Day Information Sheet. [Online]. World Wildlife Foundation; Threatened Species Network; Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tsday08-skink.html.
Threatened Species Network (TSN) (2008b). Brigalow Belt bioregion: a biodiversity jewel. [Online]. WWF-Australia. Available from: http://www.wwf.org.au/publications/reptiles-brigalo-belt.pdf.
Wilson, S.K. & D.G. Knowles (1988). Australia's Reptiles: A Photographic Reference to the Terrestrial Reptiles of Australia. Australia: Collins Publishers.
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). Egernia rugosa in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 18 Sep 2014 19:58:58 +1000.