As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Thursday 4 April 2013

Whether trill or gobble, birds sing song of attraction

Mar 27, 2013   Written by
Francis Skalicky
Missouri Department of Conservation

The more you know about bird song, the more you’re apt to be fascinated by this well-known ritual of spring.

We all know spring is a prime time to hear birds. These bird sounds can range from a cardinal’s melodious trill to a turkey’s loud gobble: All are forms of springtime bird vocalization.

These sounds that are often entertaining to human ears are necessary parts of a bird’s annual life cycle.

Why there’s so much bird song at this time of year is a well-known fact: It’s often the males that are vocalizing, and they’re usually either trying to court a female or are telling another male that he’s intruding. However, there are other details of bird song that are often overlooked, like, why does the bulk of spring bird song occur in the morning.

There are a number of theories about this and several probably have some validity.

Some biologists think birds instinctually know this is a good time to make noise — especially for courtship. There is generally little or no wind at this time of day and, as a result, bird sounds tend to carry greater distances.

There’s also a theory that, because the lower temperatures at sunrise tend to squelch insect activity and, thus, many types of birds can’t be feeding during this time, it’s a good time to work on the duties of courtship and territorial establishment.

If you stop and listen to bird songs, you’ll notice some males have a varied repertoire of calls and can sometimes make their calls quite complex. As with every other characteristic of nature, this is another form of biology at work.

In the bird world, having greater vocal skills is a sign of being stronger and healthier and a better mate. These are the kind of sounds female birds want to hear because besides survival, their other main goal is to produce strong, healthy offspring.

Physical makeup assists birds with their song variation. A bird’s syrinx — which is its voice box and the equivalent of a human’s larynx — is situated much closer to the lungs than a larynx is to human lungs. This arrangement allows birds to produce a greater variety of sounds than humans.

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