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One of the oldest debates among biological scientists is what is sometimes called “the nurture versus nature debate.” The question is whether things that animals do are all learned behaviors or simply a part of the design of their genetics, programed into their DNA at their origin. For many years, experiments have been conducted to answer this question. In previous issues of this bimonthly we have discussed migrations of a variety of animals and how those migrations benefit themselves and/or the other forms of life that share their ecosystem.

There is not much doubt about why birds sing. Contrary to what the word “sing” implies, birds are not just musicians who sing for their own enjoyment. The songs of birds have been shown to warn other birds to stay out of their territory, or perhaps to warn other animals of common dangers and opportunities. Songs are also used to attract mates.

In 1996 an interesting study was done to see what the origin of this method of attraction might be. Meredith West at Indiana University took cowbirds as the ideal subject to test theories about songs being used to attract mates. This is because cowbirds lay their eggs in the nests of other birds who then hatch and raise the babies. The mother cowbird never has contact with the offspring so she can have no nurturing effect. West housed a group of baby male cowbirds with female cowbirds, and another group with canaries. When both sets of birds were released into a common aviary, the canary-raised birds made a beeline to the canaries and sang only to them and to each other. The cowbird-raised birds flirted with the cowbirds.

What is interesting about this experiment is that when they introduced normal male cowbirds to the aviary, the cowbirds raised with canaries quickly learned the cowbird songs and became expert crooners and courtiers. Also interesting is the fact that other species of birds such as catbirds, seem to be able to develop their singing skills with no contact with other members of their species. Researchers are saying that the songs of birds have a genetic disposition, but their surroundings can affect how the songs are molded and shaped. God’s design for successful mating is seen in this, and the complexity of it is astounding. The implications for humans are significant.

Source: Science News, May 4, 1996, page 280.

Picture credits:
Roland Earnst