Thorny Devil: Problem Solving

Known by many names, Thorny Devil (Moloch horridus) is more than an ordinary lizard. With her spiky body and crown of thorns, She resembles a walking nightmare. Her other names – Moloch, Horny Devil, and Thorny Dragon – emphasize her “hellish” nature. The scientist who named Her, Dr. John Grey certainly thought that. He recalled an ancient demon from John Milton’s Paradise Lost, when he gave Thorny Devil, her scientific name. Dr. Grey also cited the Canaanite God Moloch from the Old Testament, who received sacrificed children.

Looks can be deceiving. The only animal that Thorny Devil terrorizes is Ant. She spends her day wandering in the Australian Outback, searching for their nests. When Thorny Devil finds one, She parks Herself next to its edge. Catching one ant at a time with her sticky tongue, She consumes 45 ants a minute (2,500 in an hour). Thorny Devil is the walking nightmare for ants.

As She roams the Outback, Thorny Devil slowly lifts one foot at a time. Swaying from side to side, this small harmless lizard walks jerkily across the sandy soil. Since Thorny Devil cannot run fast, She relies on camouflage to keep Her safe. To blend into the landscape, Thorny Devil changes her colors from pale yellow to olive to brown.

Herpetologist Eric Pianka described his frustrating experience searching for a Thorny Devil. Spending a day in the Great Victoria Desert, Dr. Pianka followed the lizard’s faint tracks, which went around in a figure eight. Searching for most of the day, he found the Thorny Devil’s eating spot, sleeping spot, and bathroom spot, but no lizard. Then as evening was coming, he nearly stumbled over the Thorny Devil. For the entire day, this lizard had been sitting in the center of the figure eight. In his search for the Thorny Devil, Dr. Pianka had passed the lizard many times.
 
Well-suited for living in the tough dry areas of Australia, Thorny Devil has a unique way of collecting scarce water. When a rare shower occurs, the tiny grooves between her spikes will channel the rain to her mouth. Tilting her body forward, Thorney Devil gulps down the water. In the morning, when the dew condenses on her spikes, these grooves will direct the moisture to her mouth for drinking.

Thorny Devil uses her prickly armor for defense. Her head horns warn predators like Blue-tongued Lizard that She is painful to swallow. On the back of her neck, Thorny Devil has a satchel or false head. When She tucks her head between her forelegs, Blue-tongued Lizard sees only this large spiky “head” and retreats.

Thorny Devil is a member of the Agamidae Family (“dragon lizards”). (This Family includes bearded dragons and Australian frilled lizards.) The Agamidae of the Old World are distantly related to the Iguanas of the New World. Thorny Devil most resembles “Horny Toad” (Horned Lizard (Phrynosoma platyrhinos)) of the Iguana Family. Living in the Southwestern United States, “Horny Toad” faces the same challenges. Although They belong to different families, these two lizards could be twins.

Living in similar habitats, Thorny Devil and “Horny Toad” have parallel lives. Both feast on ants, and obtain water using the same methods. These two lizards demonstrate convergent evolution, which means that evolutionary pathways can be predicted and repeated. How these two lizards solve their problems with similar methods is revolutionary in understanding the challenges of nature for every species on the earth.

Thorny Devil teaches problem solving. To live in her harsh homeland, She employs many strategies for survival. Her spines serve as double duty – scaring predators and collecting water. Amid the desert shrubs, her coloring conceals Thorny Devil. She eats the ants that are plentiful where She lives. An excellent problem solver, Thorny Devil teaches how to be effective and efficient. Let Her be your guide. Just remember that looks can be deceiving.