It truly is amazing to wake up in the morning to the sound of birds twittering and chirping in the fresh dawn air. Bird calls are a language of their own and are carefully uttered to convey important messages. Bird sounds are a great form of communication as they can be heard even when the “speaker” is not seen or is a far way off. Bird sounds are separated into songs and calls. Bird calls are simple notes produced by males and females throughout the year. The sound of bird song is more elaborate and musical, telling other birds: “This is my territory”. Different bird calls are sounded for different purposes. Contact calls keep birds in a flock aware of each others whereabouts. However in large colonies it is important to also have breeding calls which are recognized by mates, parents and young. Alarm calls attract other birds to assist in attacking predators and stopping their silent approach.
Bird song is especially important at the beginning of the breeding season, and is also prominent before migrating or when stopping along the way. Certain species defend their territory all year round and thus sing continually, and in some cases both male and female will sing for this purpose. Bird song is most effective in the morning as sound travels farther in the still air. Birds will often perch on high, exposed positions to make their voices heard, as this reduces interference from surrounding bush and allows the sound to travel more effectively.
A fascinating bird sound is that of the lyretailed honeyguide of Central Africa. This bird will fly above the tree tops whilst singing; it then spirals down from these great heights. Whilst spiraling its tail vibrates and the wind blowing through its spiky feathers sounds like a loud drum. This sound can be heard over a great distance.
Many people listen to recordings of bird calls and use these in identifying birds as each bird has unique calls and sounds. So next time you listen to birds calling outside your window, consider what message they are trying to convey.