Male bower birds attract potential mates by building an elaborate bower consisting of a tunnel-like avenue of twigs arranged in a series of arches and two court areas decorated with objects such as shells, pebbles, bones and even pieces of glass or plastic. When a female is attracted into the avenue the male flies into one of the courts and puts on a display involving moving back and forth in front of the avenue and picking up and tossing the collected objects accompanied by noisy screeching calls.
John Endler, a natural historian at Deakin University, and colleagues recorded the sounds made by a courting bower bird and then played them through speakers in a bower bird court and recorded the sound with microphones positioned in the avenue where the female would hear them. They also tested the effect of removing the court objects on the sound. They found the shape of the tunnel amplifies the sound and the objects alter the frequencies of some sounds and diminish others.
According Science News “Male great bowerbirds, it turns out, are excellent sound engineers.”
The research team claim the combination of bower building and visual displays with associated with sound is an example of sexual selection resulting in “extreme development of multimodal mate-attracting traits, including complex constructions.” One of the conclusions from their experiments is: “We need to understand how multimodal signalling evolved given that it is widespread.”
References: Science (AAAS) News 27 September 2024; Behavioral Ecology, 7 September 2024, arae070, doi: 10.1093/beheco/arae070
Editorial Comment: Sexual selection is the belief promoted by Charles Darwin and followers that certain structures and behaviours evolved specifically to attract members of the opposite sex, even if they are otherwise of no value for day to day survival, e.g. elaborate tail feathers, bright colours. However, like natural selection, sexual selection only describes a phenomenon that already exists. It does not explain how it came about in the first place. In this case bower building and the male display does attract female bowerbirds, but that does not explain how the original male birds that didn’t build bowers discovered how to build a bower, collect and arrange acoustically appropriate objects and manipulate them in the right way during their display.
Sound engineering takes plan and purpose, as well as clever manipulation of the environment and objects within it. Furthermore, it is only effective if it communicates the right message to the female birds, which means both male and female both must be pre-programmed to understand it.
Putting information into any system requires an intelligent mind at work. It will not happen by mindless chance random processes, so these scientists will not get to “understand how multimodal signalling evolved”. They will only understand how bowerbird signalling came about if they forget evolution and submit to the Creator’s word which tells us that God created birds according to the kinds, fully functional and ready to reproduce after their kinds.
Creation Research News 16 October 2024
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