In a funny face competition, the blue-tongued skink would undoubtedly win the hand… or rather the tongue! As its name indicates, the saurien of the Scincidae family actually has an astonishingly coloured organ in its mouth that, when stuck up, reveals impressive purplish reflections.
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Among the animals of the genus Tiliqua (scientific name of the blue-tongued skink), such behaviour occurs when the animal is being attacked. Spread throughout Australia, Eastern Indonesia and Papa New Guinea, these medium-sized lizards extend their jaws whenever threatened, and reveal their very ‘peculiar’ tongue. And that’s an understatement.
An ultraviolet tongue
Their tongue is tinged with such an intense and luminous colour that it falls under the ultraviolet scale, meaning it emits radiation that is invisible to the human eye, but to which many other animals are sensitive. Among these animals are some birds, snakes and monitor lizards, all of which are predators of a particular subspecies of blue-tongued kink: Tiliqua scincoides intermedia.
It’s this exact family that scientists have managed to examine during a study, that was published yesterday in the Behavioral Ecology and Sociobiology journal. Their goal was to identify the processes linked with the blue-tongued skink’s strange ultraviolet colour.
To achieve this, the researchers first measured the intensity and wavelength of the a dozen lizards’ tongues using a portable spectrophotometer. They found that, in addition to its ultraviolet colour, the tongue is also almost twice as bright underneath as it is at the tip.
The blue-tongued skink can therefore make the most of its camouflage abilities until just before it gets attacked by a predator. With dark stripes on its sides and orange streaks on its backbone, the animal blends perfectly into its environment. That is, until it suddenly shoots out its ultraviolet tongue, just a fraction of a second before his attacker gets to him.
False attacks
With the help of this discovery, the researchers then began to simulate predator attacks by confronting the lizards with a series of fake opponents, such as snakes, birds and other foxes. They also used a goanna (a type of Australian monitor) as well as a simple piece of wood. In a controlled environment, scientists were able to observe the blue-tongued skinks defense strategy when faced with a predator.
“The lizards restrict the use of full-tongue displays to the final stages of a predation sequence when they are most at risk, and do so in concert with aggressive defensive behaviours that amplify the display, such as hissing or inflating their bodies”, says Arnaud Badiane, from the Department of Biological Sciences at Macquarie University in Sydney, Australia. Arnaud was the lead author of the experiments.
According to the researcher, this strategy proved “particularly effective against aerial predators, for which an interrupted attack would not be easily resumed due to loss of inertia”.
A flexible response
Another interesting detail that the scientists found was the lizard’s defensive response was proportional to the importance of the threat. The more intense the attack and greater the danger, the more the skink shot out its tongue, at best revealing the dazzling colour of its tongue. This is a strategy that is mostly used during bird or fox attacks, rather than snake or lizard attacks. We now know about the blue-tongued skinks fiercest enemies … and for this animal, timing is everything.
“The timing of their tongue display is crucial,” adds Badiane. “If performed too early, a display may break the lizard’s camouflage and attract unwanted attention by predators and increase predation risk. If performed too late, it may not deter predators”, the scientists explains. In a funny face competition, the blue-tongued skink would do well to bide its time if it wants to win!
Check out the video above to see the incredible blue-tongued skink for yourself!
