Would you know what species to mate with if you'd grown up alone and didn't have a mirror? That's the challenge faced by the Australian brush turkey, which hatches alone in a warm mound of rotting leaf litter. Now, with the help of remote-control robots made from toy car motors and the skins of dead chicks, a research team has gleaned the first insights into how the brush turkey recognizes its own kind.
Most birds learn to identify their own species by "imprinting" on their parents while their nervous system is still at an impressionable stage, but for brush turkeys (family Megapodiidae) that's not an option. Females lay eggs in a compost heap built by the male, then leave the incubation up to the heat from decomposition. That means the chicks can't imprint. "It's the most nonavian life history you can get among creatures that are still feathered and lay hard-shelled eggs," notes Mark Hauber, a behavioral ecologist at the University of Auckland in New Zealand.
To find out how a newly hatched chick would recognize another brush turkey, Ann Göth and Christopher Evans, animal behaviorists at Macquarie University in Sydney, Australia, presented chicks with a choice of brush turkey robots. The chicks found a pecking imposter more attractive than either a still robot or one turning from side to side. And when ultraviolet light was filtered out, the chicks lost interest even in pecking robots, suggesting that both eating behavior and color help brush turkeys identify members of their own species, the scientists report in the 1 June Journal of ExperimentalBiology. Brush turkeys may spend their formative days alone, but a little mood lighting and the right moves are all it takes to bring them together.
More about Göth and Evans's research