Decisive Designs: The Mallee’s Tongue: Terrific Temperature-Telling Talent
The modern inventions and innovations of man can be seen in almost every facet of our lives. The thermometer is one fine example of human ingenuity. Parents are familiar with taking their children’s temperature (sometimes quite frequently). Insert a thermometer, and voilà! Several seconds later, the temperature is displayed as a bar of mercury (or electronically), and one can read the temperature with ease. Even as we give homage to these fascinating devices, on occasion we tend to remain blind to the equally fascinating design that has been imprinted on the Earth and its creatures by the Great Designer. Take the mallee fowl, for example. Before man ever even thought of creating the simplest of contraptions, this bird was assessing temperature for its unborn babies. As the apostle Paul put it: “God has chosen the weak things of the world to put to shame the things which are mighty” (1 Corinthians 1:27). Man’s conceptions may be mighty, but God has put them to shame with a bird as simple as the mallee.
The Outback of Australia is home to this magnificent bird. The hot temperatures and dry climate do not deter the mallee, though. During its mating season, the male creates for its partner’s eggs a nest that has an average circumference of 70 feet, and is over three feet in height. In the 1700s, the first white settlers came upon the mallee fowl’s nests and, due to the unbelievable size of these sandy dunes, at first believed that they were aborigine burial grounds (Junor, 1998).
In order to make its nest, the male must first dig out a hole in early winter. Over the course of the winter, the mallee will begin to place sticks and other brush inside the hole, forming a canopy of litter across the top. As spring begins, the mallee fowl will cover the debris with a layer of sand to allow for fermentation of the litter beneath the surface. The nest will remain in this state until mating season (autumn). At this point, the nest has been thoroughly warmed by the decomposed waste. The male makes a hole in the top of the mound, where the female then lays a single egg. About a week later, the male will make another hole and the female will lay another egg. This process goes on until there are about eighteen eggs in the nest.
But building a nest is only half the battle. The other half involves temperature maintenance in the mound. This job, once again, is left to the male mallee. Several times a day, the male inserts his beak into the pile of debris and sand. He proceeds to stick out his tongue, which is such a good thermometer that it can measure a temperature change as small as 1/10 of a degree! After assessing the temperature, the male can act accordingly. If the nest is too hot, he removes some of the sand covering the nest. If the nest is too cold, the male adds sticks to produce more heat, and sand to insulate the mound from the surroundings. The temperature must be kept at exactly 33 degrees Celsius, and must be maintained to within one degree in order for the unborn chicks to survive while still in the nest.
This scenario gives rise to important questions: (1) How did the mallee fowl “know” to pile sticks and other debris inside the nest in order to moderate the temperature? (2) Why (and how) did such a temperature-evaluating device arise (in the form of a tongue)? Tough questions—the answers to which lie in the intricate design of this amazing bird that is attributable to the Great Designer.
Junor, Lloyd (1998), “The Mallee Fowl,” Whimpey’s Little Desert Tour, [On-line], URL: http://www.aussieoutback.com.au/showcase/whimpy/lowan.html.