Yakka skink - Egernia rugosa

CONSERVATION STATUS

Australian Government: VULNERABLE
Environment Protection and Biodiversity Conservation Act 1999
Queensland: VULNERABLE
Nature Conservation Act 1992

Introduction

The Brigalow Belt bioregion is a large and complex area covering 36,400,000ha that has been identified as a biodiversity hotspot by the Australian Government. It has been recognised for its biodiversity values and the existing levels of threat to those values. It is home to a dazzling array of distinctive flora and fauna, including the yakka skink.

Did you know?

The yakka skink is an extremely secretive species, hiding under rocks, in hollow logs or ground vegetation, or in burrow systems. Its presence is often indicated by a pile of droppings near shelter sites.

What do they look like?

The yakka skink is a robust lizard around the same size as a blue tongue lizard. The average size from head to tail tip is 40cm, making it one of the largest skinks in the region. Its body colour ranges from pale to dark brown, usually with a broad dark brown stripe extending along the back from the neck to the tail. This dark stripe is bordered on either side by a narrow, pale fawn stripe. Some of the scales at the rear of its head are fragmented, so it lacks the symmetrical arrangement of other skinks. There are several large, platelike scales along the leading edge of the ear, partly concealing the opening.

Where do they live?

The core of the yakka skink's distribution is within the Mulga Lands and Brigalow Belt South bioregions. Other populations are scattered throughout the Brigalow Belt North (east to the Rockhampton area) and Einasleigh Uplands bioregions, extending northwards to southern Cape York Peninsula. Recent surveys have detected populations along the Queensland/New South Wales border.

Yakka skinks occur in a wide variety of vegetation types including poplar box, ironbark, brigalow, white cypress pine, mulga, bendee and lancewood woodlands and open forests. Substrates include rock, sand, clay and loamy red earth. They can persist in clearings where shelter sites such as tunnel erosion, rabbit warrens and log piles exist.

Yakka skink life history & ecology

The yakka skink is active during cooler parts of the day, dusk and sometimes at night. Individuals dig a deep burrow system under and between partly buried rocks or logs, or into old root tracts at the base of remnant stumps. They may also utilise old rabbit warrens, deep gullies, tunnel erosion/ sinkholes or under rural buildings.

The yakka skink is omnivorous, consuming soft plant materials and fruits and a wide variety of invertebrates (beetles, grasshoppers, spiders) that venture into or near the burrow entrance. It produces live young, with around six per litter.

Threats to the yakka skink

Loss of habitat due to clearing and thinning

The focus of vegetation clearing in the Brigalow Belt is shifting from the essentially cleared Brigalow ecosystems on fertile soils to the eucalypt woodlands on poorer soils. Consequently the survival of dry woodland/open forest species with limited geographic ranges and/or specialised habitat requirements, such as the yakka skink, remains uncertain unless conservation action is undertaken.

Inappropriate roadside management

Roadsides and road reserves often provide suitable reptile habitat. Populations of reptiles that live within linear remnants, such as roadside strips, are particularly vulnerable to disturbances that remove essential microhabitat features, for example, rocks, logs, dense leaf litter and fallen bark. Road widening and maintenance works may also impact on yakka skink populations by destroying burrows.

Removal of wood debris and rocks

This species is threatened by the removal of its microhabitat, which includes partly buried rocks, fallen logs and leaf litter.

Ripping of rabbit warrens

The practice of ripping rabbit warrens is known to kill yakka skinks as well as other species like woma pythons, and also destroys important shelter sites.

Feral animals

The yakka skink is vulnerable to predation by foxes and feral cats.

Case Study - A botanic refuge

The Myall Park Botanic Gardens, maintained by volunteers and a caretaker, is a safe haven for the threatened yakka skink. In 2007 the gardens applied for a TSN Community Grant to help protect the skink and many other species from feral predators and grazing animals, which degrade the habitat.

The yakka skink is the flagship animal for the local town and the Gardens are vital for its survival.

The project has two aims. Firstly, to reduce the number of grazing animals, such as rabbits and kangaroos, so habitat isn't degraded further. Secondly, to reduce foxes and cats, which prey on vulnerable reptiles like the yakka skink and birds that use the gardens.

Important areas of high biodiversity value within the Gardens have been enclosed with a mesh fence to protect habitat. A floppy type of mesh is being trialled to see if it can keep grazing and predatory animals out without restricting the movement in and out for smaller animals such as other reptiles.

Community members are helping the conservation of the yakka skink by taking part in the fox and cat trapping. Workshops have been held to train community members in the safe use of the traps. This will hopefully lead to a gradual reduction in the numbers of feral cats and foxes in the local area.

What you can do

• Maintain large, healthy, connected patches of suitable habitat - for example poplar box, ironbark, brigalow and mulga woodlands.
• Retain fallen timber and ground cover as these provide essential habitat.
• Implement coordinated feral animal control measures.
• Survey roadsides before undertaking road widening or maintenance operations. Flag and protect suitable habitat and burrows if found.
• Avoid disturbance of colonies by ensuring grazing practices are sustainable, maintaining good ground cover or restricting grazing by fencing if necessary.
• If burning, use cool burns in a mosaic pattern that promote patchiness and leave areas of ground cover unburnt.
• Consider entering into a conservation agreement for conservation and land management assistance.
• Report sightings to the TSN. Taking a photo of live or dead specimens is useful to help identification.
• Help the yakka skink by reporting any activities that you see that are likely to harm them or their habitat to the Department of the Environment, Water, Heritage and the Arts - Compliance and Enforcement Branch. Visit www.environment.gov.au/epbc/compliance/index.html or freecall 1800 110 395 for more information.

Contacts

TSN Coordinator:
Eastern Temperate Forests
WWF-Australia
P 1800 032 551
E tsnnsw@wwf.org.au

References

Environmental Protection Agency (Queensland).

Richardson, R. (In prep). Draft National recovery plan for Queensland Brigalow Belt Reptiles. Report to the Department of the Environment and Water Resources, Canberra. WWF - Australia.