Jeffrey Low
email: jeffctlow@yahoo.com



Wednesday, July 8, 2009

ABOUT THE SONGS OF THE WHITE-RUMPED SHAMA

Wild shamas from different localities will have different song types or vocal dialects. Although they are able to learn new songs throughout most of their captive lives, adult wild-caught males will still have a strong tendency to sing more of the types of songs that originate from their localities.

Male shamas chicks that are taken from the wild when they are too young, such as nestlings, will be lacking in the vocal dialects of their localities when they mature later on. If these young chicks are kept without tutors in the early weeks, they will also be limited in their variety of songs when they mature. In comparison, juveniles taken from the wild at a much older stage are capable of producing the vocal dialects of their localities later as adults and very young chicks that are taken from the wild but are well exposed to tutors during their first few weeks, tend to mature with more varied songs than those kept without tutors. This serves to confirm the theory that there is a crucial learning period in the early weeks of their lives when the male shama chicks will store songs they heard into their brains. The songs of their male parents and other neighbouring males as well as certain sounds from their natural environments will constitute their vocal dialects.

Hobbyists from different parts of Asia have different preferences when it comes to the different song qualities of the white-rumped shamas. In some places, emphasis is placed on the melodic quality of the songs and in other places, variety of songs and not necessarily the melodic quality, is preferred. Some hobbyists will nurture their birds from a young age by minimizing undesirable sounds in their environments and exposing them more to the preferred kind of vocal qualities. In other areas where the preference is towards variety, the ability to mimic sounds of other animals or the natural sounds of the forest is greatly valued. In any case, the ability of the male white-rumped shama to expand its repertoire through learning new songs from others of the same species as well as from other species is quite well known amongst hobbyists.

Although they are quite capable of copying the songs of other species of birds, often, the copied songs may be different in tonal qualities from that of the source. They are also capable of mimicking certain mechanical sounds from their surroundings, such as the sounds of sirens and car alarms but it seems that these mimicries of mechanical sounds are mostly heard only during the renditions of their subsongs and are not incorporated into their loud territorial songs.

The syrinx is the vocal organ of the bird. It consists of two parts located at the lower end of the trachea and has highly elastic membranes. The muscles of the syrinx controls the tension exerted on the membranes by the air from the lungs and by adjusting the pressure of the air and the tension on the membranes, birds are able to control the loudness and pitch of the sounds emitted from the syrinx. In highly developed passerines, it has been shown that the two sides of the syrinx can operate independently and can produce two separate tones simultaneously. Some male white-rumped shamas from certain areas are known to be able to do this by sometimes producing a two-toned voice simultaneously.

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