Learning to sing
The songs of birds have delighted musicians for centuries. In the 18th century, George Frideric Handel wrote a concerto imitating the calls of the cuckoo and nightingale.1 In the 20th century, French composer Olivier Messiaen imitated bird songs in a quartet2 he wrote while imprisoned in a German POW camp. Bird songs were sounds of freedom to the captives, and they truly appreciated them.
But how do birds learn the songs we all love? It’s still somewhat of a mystery, but one person who can give us some clues is Dr Michael Tarburton, a creationist ornithologist who lives in Papua New Guinea.
Michael Tarburton is a true bird lover. Growing up on a small farm in Albany, Western Australia, he says, ‘I just had to become interested in the insects, reptiles and birds in the bush around our house.’ When he was six years old, his family moved to Perth, and he became more seriously interested in studying insects, fish and birds as a hobby. Researchers at the local CSIRO3 Wildlife Division answered his questions and encouraged him greatly.4
Dr Tarburton recalls frequently riding his bicycle out of town to observe birds and collect orchids, insects and reptiles or fish. ‘One route I enjoyed was a 75-mile ride through the Darling Range, which always took a full day to complete, but it would produce some good sightings and often reptiles to take to the naturalists’ club wildlife show. I would cycle often to the library to gather information. And I would cycle to birding spots to observe and record the birds that were there and try to determine why the different species preferred different locations. It grew from there.’
As Dr Tarburton’s interest in nature grew, so did his interest in the Maker of nature. ‘By the time I was in mid high school I was a committed believer, and by the time I was in upper high and college I was asked to take meetings on God in nature, and creation–evolution.’
For sceptics who wonder if creationists are involved in ‘real science,’ Dr Tarburton is an example.
Mike went on to receive his Ph.D. in zoology from Massey University in Palmerston North, New Zealand. His writings on the behaviour of birds have been extensively published in peer-reviewed journals and birdwatchers’ periodicals, and he has taught science at high school and university levels.
Nature or nurture?
So how do birds learn to sing? Do they inherit their songs or do they learn them? It’s a very tough question! Mike says, ‘It varies a great deal between species. Obviously, inheritance must play an important part. Brood parasites, like cuckoos, honeyguides and cowbirds lay their eggs in the nests of other birds. Just think of the problems that their nestlings would have if they learned the songs of their foster parents instead of their own species. How would they attract or recognize a mate?’
In fact, it’s been shown for many birds (such as doves,5 chickens6 and some flycatchers7) that their calls or songs are completely inherited. Dr Tarburton says, ‘Even when such birds are raised in soundproof isolation—or are deafened before ever hearing another bird—they can, when adult, give normal calls or sing normal songs.’
But inheritance can’t explain it all. Some birds inherit the ability to sing basic songs, but they need outside input to develop a ‘full’ song, with the full range of variations. ‘An example would be species such as zebra finches and indigo buntings, which need vocal interactions with other birds to develop their song potential.’8
Dr Tarburton also tells about the interesting case of the rotund little European chaffinch. ‘This bird normally sings about six different songs, consisting of three trilled phrases and ending with a flourish. In the wild they develop a full song during their first spring.’ But under unnatural conditions, some interesting facts were observed:
‘If a male is raised in isolation it will develop a simple song with no phrases and no final flourish.’9
‘If several young chaffinches are raised together, but are isolated from all other sounds, they develop slightly more elaborate songs.’
‘If wild males are captured before their first spring, but after they have heard adults sing during their first three months, they develop a complete song. Even when placed in isolation, they develop full three-phrase songs with a final flourish. And after their first breeding season, the song of male chaffinches is “crystallized”. It will not change, even if they are placed with other adults from other regions that sing a different song.’
This all seems to indicate that part of their song is inherited and part learned. The learning occurs only in an early sensitive period of their life,10 and seems to be guided by inherited ‘brain wiring’. This concept of brain wiring in birds (an ‘innate template’) was suggested 40 years ago.11 Dr Tarburton says that this theory is helpful for understanding how birds learn to sing, but it’ still unproven. ‘We know little or nothing about the nature of the “template” itself.’
We do know something about the function of bird song, though. ‘Bird song functions to keep species from interbreeding, and enhances the variety in God’s created world.’ Dr Tarburton points out that even where two species probably descended from the same biblical ‘kind’ of bird, natural selection could have sorted the genes from the parents so that the descendants learn in different ways. For example, swamp sparrows and song sparrows can learn only their own songs. Swamp sparrows learn only from the ‘structure’ of the song, and song sparrows only from the ‘timing’. Neither can learn the songs of the other, and thus they don’t interbreed, even though they are probably the same kind. Dr Tarburton reminds us that all of this is downhill change, the opposite of what would be needed for evolution.
In this area, there is so much variation among birds; so far, no-one has been able to find a one-size-fits-all theory to explain every situation. Dr Tarburton tells of some birds that can change their song completely! They can even develop a ‘private repertoire’ that is used only occasionally (such as in aggressive behaviour). For example, ‘first-year male indigo buntings imitate the song of an established neighbour when setting up a territory.’
And new things are being learned all the time. Dr Tarburton lives on the campus where he teaches, which is also a beautiful bird sanctuary where numerous species come to sleep in safety. ‘We have three artificial lakes that attract lots of waterbirds, in addition to the many bush-birds. Bird watchers from around the world come to the campus to see some of Papua New Guinea’s birdlife. We have grey shrike-thrushes [pictured here] living around our home here, and we have noticed that every few months the bird nearest our house changes some of his calls. Sometimes these calls are very different from his previous ones. Whether he learns from neighbours or from experimentation I do not know—but I do know that God gave him this incredible ability and that science still has a long way to go to learn how he does it.’
Creationist in academia
It has not always been easy to be a creationist in the not-completely-tolerant halls of academia. Dr Tarburton encountered a strong bias in favour of evolution, especially among government educators. ‘Of course, studying evolution at the graduate level forced many issues into the open. My supervisors knew where I stood and they appeared to respect me for my arguments. I found some very bright people at Massey University, and they were mostly able to accept that not everybody had to have the same view as themselves on everything.
‘My practice has been first to demonstrate that I am normal and can deal academically with the content matter, the processes, theories, etc. Then creation and evolution will come into discussions and they will listen to my point of view with more of an open mind.’
Anticreationists often say that creationists can’t be good scientists. They incorrectly say that creationists will give up on hard problems with a shrug and the comment, ‘That’s how God made it.’ But to the contrary, Dr Tarburton’s attitude is to be in awe of God’s handiwork—and, when we don’t understand it, keep studying it!
‘What I do know is that the variety of calls throughout the 10,000 bird species and the variations within species demonstrates what a great Creator we have. He enables not only species and individual recognition within the same call or song, but also uses the same song for territorial defence, mate advertising, and the fascination of human hearers. Bird songs are also a challenge for ornithologists such as me to better understand His ways—which are often “past finding out”.12 The more we learn, the more complexity, as well as beauty, emerges in His creation.’
References and notes
- Organ Concerto no. 13 in F, ‘Cuckoo and the Nightingale’. Return to text.
- ‘Quartet for the End of Time’. Return to text.
- Commonwealth Scientific and Industrial Research Organisation (Australia). Return to text.
- One of the people who encouraged him was renowned ornithologist Dr Dominic Serventy. Return to text.
- Nottebohm, F., and Nottebohm, M.E., Vocalisations and breeding behaviour of surgically deafened Ring Doves (Streptopelia risoria), Anim. Behav. 19:313–327, 1971. References courtesy of Dr Tarburton. Return to text.
- Konishi, M., The role of auditory feedback in the vocal behaviour of the domestic fowl, Z. Tierpsychol. 20:349–367, 1963. Return to text.
- Kroodsma, D.E., Songs of the Alder Flycatcher (Empidonax alnorum) and Willow Flycatcher (Empidonax traillii) are innate, Auk 101:3–24, 1984. Return to text.
- Payne, R.B., Song learning and social interaction in Indigo Buntings, Anim. Behav. 29:688–697, 1981; Adret, P., Operant conditioning, song learning and imprinting to taped song in the Zebra Finch, Anim. Behav. 46:149–159, 1993. Return to text.
- Thorpe, W.H., Bird-song: The biology of vocal communication and expression in birds, Cambridge University Press, Cambridge, UK, p. 72, 1961. Return to text.
- This is partially determined by male hormones. See Danforth, J.W., 26 June 2004. Return to text.
- Margoliash, D., Evaluating theories of bird song learning: implications for future directions, J. Comp. Physiol. A. 188:851–866, 2002. Return to text.
- Romans 11:33. Return to text.