DAWN CHORUSIt is usually in the early summer or spring, in most parts of the world, that birds get into their singing moods. As the beginning of the breeding season starts, the birds, especially the males, looking like they stepped out of Savile row in their resplendent new plumage, test their musical skills to attract the suitable ladies of the species .They can be heard anytime but the best time is about an hour before sunrise and for another two hours after. There is plenty of daytime, as I mentioned earlier and potential suitors find the highest perches and belt out song after song till they catch the attention of a mate. While most singers are male some females too join the fun.
|Oriental Magpie Robin|
If you listen carefully everyday, you'll find some species start earlier than others. In my place it is the Asian koels, oriental magpie robins and white-throated kingfishers start their singing before sunrise. (Click this LINK to listen to the birds that join in the Avian Orchestra at my house) As the east lights up the red whiskered bulbuls, tailor birds and others join the chorus. Everyone is in trying to outdo each other because there is nothing better to do at that hour. The light is low, there fore predators won't see you easily. Potential food like the insects and flying termites will get active only after the sun warms the air and the earth. Besides the light may not be enough to detect them. In urban environments the sound carries further as traffic and the cacophony of a city won't drown out the songs!
If you are an early riser and carry your newspaper to the bathroom for a leisurely read while sitting on the best seat in the world, the potty seat, you can keep an ear out for this dawn chorus. Birds wake up before sunrise and warm up while you are trying to read that newspaper and complete the most important activity of the day!
BIRD SONGS & CALLS
Birds vocalize differently depending on the situation, season and location. Their voices can be broadly divided into two, the songs and the calls. Please note, I used the word 'voices' in the previous sentence because there is also another type of sound, the non-vocal sounds, which we will see later.
Birds sing, mostly the males of the species, during the breeding season. The males, especially, use their talent to advertise their availability to the females. Not only is it a trick to attract mates but also to ward of threats in the form of other birds competing for the same mate or territory. It is also used as a tool for bonding with the mate and their young. Songs are more complex acoustically, have a definite rhythm, are longer and get repeated over and over again. Some birds have more than one type of song and they can go through the entire repertoire in one go.
Most song birds are usually those that breed where visibility is low, meaning, in habitats where visual connection is difficult, like in thick forests, dense shrubs or even open areas where grass and bushes grow tall. In such situation a call is used to attract the attention of a potential mate or warn other birds intending to enter the territory of the singer. If you have observed, birds that forage or breed in open places like cormorants, darters, ducks, egrets, heron and storks rarely sing. They usually make a sound only when alarmed or when fighting off competition.
Calls are vocalizations that are made at other times of the year after the breeding season is over. They are short, not very musical and acoustically simple. They are used to communicate within a flock, to keep tabs on location of individuals or as an alarm to warn about an imminent danger.
(The LINK to the call of the Oriental Magpie Robin)
NON-VOCAL SOUNDSThere is one other aspect of bird sound, the non-vocal sound. Bird songs and calls are produced in the bird's voice box called the syrinx but there are birds that have poor vocal ability despite the presence of the syrinx. Such birds use other parts of their anatomy to produce sounds. They use bills, feet, tail or wings to produce sound. Albatrosses, some herons and storks, clatter or tap their bills to communicate. Snipes and swifts can vibrate their tail feathers to produce a rattling or whistling sound. All woodpeckers have a very specific rhythm to their tapping and the species can be identified by just listening to it.
|Black-rumped flameback (Non-vocal call)|
MIMICRY ARTISTESMany a time, I've heard a shikra call around my house and rushed out with a camera or microphone only to see a racket-tailed drongo shaking in laughter as it succeeded in fooling me again! Most of us would have heard a parrot or myna imitate sounds and even 'speak' human languages. However, in nature, there are a large number of birds that can imitate both animate and inanimate sounds. Some jays, starlings, mockingbirds, magpies and the lyre bird are all great imitators. They imitate, among other things, predators, other birds, insects, squirrels,vehicular horns or alarms, door chimes, chain saw, phone ringtones and much more.
In our part of the world the commonest mimicry artiste is the racket-tailed drongo. It can imitate many birds, animals and inanimate sounds. The ones around my house imitates shikras, babblers, bulbuls, kites, squirrels, whistle of a bus conductor and more! Other birds found on the Indian sub-continent that imitate well are larks, leafbirds and shamas.
The mimicry serves two purposes. One is for establishing territory and attracting a mate and the second is to scare away foraging birds to steal their food!
Next time you hear a bird outside your window, try to identify the call. You can record it on to your mobile phone and compare it with bird sounds on websites like Xeno-Canto or eBird. Once you get the hang of it, identifying the birds around you will be a breeze. Not only that, it will amaze you what birds are capable of, when they put their minds and syrinx into it!