Lizard's come-hither behaviour attracts from a distance

The females of a reclusive endangered lizard species may be increasing their chances of finding a mate by engaging in unusual behaviour which attracts males from up to 100m away.

The Australian pygmy bluetongue lizard (Tiliqua adelaidensis) spends most of its time in burrows made by spiders, making it hard for researchers to understand its mating habits.

Investigators installed CCTV cameras in 23 burrows for 10 days of each month between October 2011 and February 2012 to better understand how males found females to mate with.

Murdoch University post-doctoral fellow Stephanie Godfrey says the females in this lizard species seem to attract the males rather than vice versa.

"Through the video recordings we observed the females making these strange movements outside their burrows and normally pygmy bluetongues will go outside of their burrows for two reasons and that is to feed or to defecate," Dr Godfrey says.

"We hadn't observed that before; we didn't have much of an understanding about how males find the females."

Dr Godfrey says genetic work shows males have multiple paternity, and sire offspring from up to 100m away, a considerable distance for such small lizards.

"We don't know whether the males detect females from that distance, but suggested in our current paper, when they go in search of females to mate with, their likelihood of detecting females is enhanced by the lures described in this paper," she says

Scent-trails may be key to homing ability

Those lures could be scent trails directing males to the burrows, but it remains to be tested.

"Lizards use chemical signals a lot, they have quite a well-developed olfactory system, and they tongue-flick to find their way around the environment," she says.

Dr Godfrey says the footage was not clear enough to determine if females were rubbing parts of their bodies along the ground, or if males were using tongue flicks to sense the trail.

"When the males are coming along they're hitting these paths and following them down to the burrow where they then yank the female out and try to mate with her," she says.

"This pattern of behaviour only occurs in the females and only in October, which is when they're mating and they don't do it any other time of the year, which is fairly strong evidence to suggest that it is a fairly significant behaviour for their mating strategy."

Dr Godfrey says other lizard species have a higher chance of finding a mate because they are not restricted to burrows like the Australian pygmy bluetongue.