Secret yakka skinks battling predators and habitat loss as they stand on the brink in outback Queensland


Stephen Peck’s eyes light up when you say the word “yakka”.

Mention the unusual name ER 181, and his smile widens as his dark brown eyes grow considerably brighter.

ER 181 is Mr. Peck’s favorite.

“It’s a love story like no other,” he says.

“Not the sexiest name. ER refers to the species, Egernia rugosaand I first recorded it in January 2009, but to me it’s the cutest, sexiest reptile in the world.”

A PhD student at the University of Southern Queensland, Mr Peck has been studying the endangered yakka skink in the mulga lands surrounding Charleville in western Queensland since 2008.

Over the past 14 years, he has monitored up to 40 sites in preferred yakka habitat.

Mulga and Brigalow provide perfect conditions for research sites to establish vital information on the rare yakka.
(ABC Western Qld: Danielle Lancaster)

The skinks are meticulously measured, photographed, weighed and the information placed in detailed profile books by Mr. Peck.

For this remarkable member of the lizard family, this vital information is a database to save another endangered Australian reptile.

Mr. Peck measures the length of a yakka lizard's snout
Mr. Peck measures the length of a yakka’s snout.(ABC Western Qld: Danielle Lancaster)

Yakkas are different

Yakkas are not like many other reptiles.

They live in family groups, have a common pile of excrement, and on the creamy throat of each yakka there are black spots, no skink has the same markings.

A close up of a yakka's cream throat with black markings
The markings on the yakka’s throat are a way to identify each animal without two being identical.(ABC Western Qld: Danielle Lancaster)

Yakka skinks can have two eye colors – red or brown – but the reason for this unusual trait remains unclear.

“I wish it were as simple as sexual dimorphism, but unfortunately it’s not,” Peck said, referring to the condition in which a species’ sex determines whether it has a specific attribute.

two yakka skinks showing one with red eyes and one with brown eyes
Red and brown eye coloration is one of the many differences between yakka skinks and other lizards.

(ABC Western Qld: Danielle Lancaster)

Docile lizards are perfectly camouflaged for their chosen environment.

The colorations range from pale brown to dark brown, depending on soil coloration, leaf litter, and general environment.

A yakka skink lying in leaf litter in the wild
The distinct markings of yakkas suit their environment.
(ABC Western Qld: Danielle Lancaster)

At up to 40 centimeters long, they are not tiny garden skinks – they are about the size of a blue-tongued lizard.

The yakka shares two characteristics with all skinks: it stores energy, or fat, in its tail and has the ability to drop its tail when threatened, before it heals and regrows.

A yakka that has lost its tail
Yakkas drop their tails as a defense mechanism developed over millions of years to distract predators.(ABC Western Qld: Danielle Lancaster)

Why are the yakkas threatened?

Yakkas are thought to live for up to 30 years and are “site dependent, which means if the site is disturbed they won’t move”, Mr Peck said.

ER 181, the love of Mr Peck, he reckons, could be 19 after he first recorded it in January 2009.

“They love an old log pile, abandoned rabbit holes, and I often hear stories from landowners saying they have this big lizard living under their mowing shed.”

There are a number of causes for the yakka’s decline, which has seen it become vulnerable.

Although habitat loss is a major factor, predation by foxes and feral cats plays high on the list.

“Cats and foxes have a keen sense of smell, and yakkas are creatures of habit. The smell of communal latrines attracts wild predators who quickly learn to wait and pounce.”

Mr Peck said he regularly sees wildlife strikes, both on tracks around his sites and on night vision cameras.

A wildcat chasing a yakka skink
A wild cat is photographed chasing a yakka on a camera.(Provided: Stephen Peck)

The future of the yakka

As yakkas bask in the sun, clinging to the last fragments of brigalow and mulga to survive in outback Queensland, Mr Peck strikes a positive note.

“It’s been a crazy growing season, with some up to 20 millimeters taller than typical growth patterns,” he said.

According to Peck, as more people are educated and informed about how to recognize and protect the “sexy” reptile, there is always hope.

A yakka skink basking in the sun at the entrance to a burrow
A mulga yakka lands near Charleville in western Queensland.(ABC Western Qld: Danielle Lancaster)

Comments are closed.