Many local birdwatchers are able to recognise the birds behind the songs. However, interest in most cases ends there except for a few who make basic recordings.
Erik Mobrand posted the first account on vocalisation as far back as October 2007. We had a post after this encouraging birdwatchers to enter the world of bird calls and songs. A few responded, among whom are Lena Chow who posted an account on the subsong of a juvenile Tiger Shrike (Lanius tigrinus), among others. Another regular contributor is Dato’ Dr Amar-Singh HSS, whose latest post is found HERE. And then we have KC Tsang’s contribution.
Avian vocalisation refers to calls and songs. Calls are short and simple, made in the context of alarm, distress, contact, courtship, feeding, aggression, etc. Songs on the other hand are fairly long and complex, generally made by the male of the species to defend his territory and to attract a mate.
Songs are confined to a group known as songbirds or oscines. The chicks of songbirds learn how to sing at a young age. They memorise the songs of their own species but do not attempt to sing until after fledging. The early songs they sing, known as subsongs, are unstructured, jumbled and incomplete. These are sung softly and often, and it may take up to a year before the songs are perfect. On the other hand, calls are innate.
While many birds sing only one song, others may have a repertoire of 20 or more. In such cases one song may be sung often, the others with varying frequency. And the order of singing the different songs varies.
Birds of a species from different geographical locations may sing variations of the same song, known as dialects. Thus a migratory species may sing a different dialect from what a resident species may sing. Dialects develop when a young bird moves to a new location to establish its territory and to breed. The male then needs to learn the variation of the original song males of the new area sing. Unless the newly arrived male adopts the dialect of the new area, he may not be able to attract a mate. The juveniles of any mating in the new location will be bilingual, as they experiment with the two different dialects.
It would be interesting to document the various calls local birds make and the circumstances under which these calls are made. Also, the different songs a species make and whether they are simply dialects or actually different songs. And what about singing females? Among which species do both the male and female sing?
We can start documenting calls and songs by transcribing them in a “descriptive” way or render them in a more innovative manner like western birdwatchers do as in the song of the chickadee as “hey sweetie” or “chick-a-dee-dee-dee.” These may be more mnemonic than scientific, but if they serve the purpose, so what?
For the tech-savvy, there are many digital recorders that can be used. As Sun Chong Hong wrote earlier, “It was recorded with my compact superzoom (up to 432mm equiv.). It has a built-in stereo mic and can record sound clip with a data rate of 16 bits and sampling rate of up to 44.1Khz – which means fairly good quality recording. Besides it can record video at 640×480 resolution and 30 frames per sec. I have used it to record a pair of Collared Kingfisher (Todiramphus chloris) in the process of carving out a nest in a tree trunk. For those who dread lugging lots of equipment, a compact superzoom may be a good alternative.”
There will always be time to advance to more sophisticated equipment and even to produce sonograms of the vocals later for those wishing to proceed further.
Simply watching and listing birds may satisfy some birdwatchers. For others who need more challenging activities, entering the world of bird vocalisation is a field worth going into. After all, with only 300 or so species that can be seen in Singapore, many seen only during the migratory months, how long would it take a newcomer before he or she would have seen most of the more common species? And unless more challenging activities are encouraged, many will simply drift away… or twitch.