American robins have always been known for their early morning and late evening caroling. Few sounds are as rich, clear and beautiful as the song of the robin. They begin singing before the sun crests the horizon and will continue on into the deep dusk.

It has been this way throughout the ages, for eons, and was as sure as the sun rising. Yet, here we are, experiencing some really big changes, in the modern day, at a place in time, where man, having altered his environment, is beginning to see his impact on nearly every living creature.

We can see our impact on the planet in the larger systems, such as is now taking place with global climate change - we don't often hear much about the smaller, unexpected discoveries, indicative of the larger impact. For example, there are many cases of changes in the behavior of wildlife.

One in particular, is the growing trend of robins singing at night. Night singing is expected for some species, such as mockingbirds and ovenbirds. Mockingbirds sing incessantly and can often be heard breaking into song late at night; oven birds will sometimes fly above their territories and burst into night song.

Robins have never been nocturnal singers - until now.

For many years, ornithologists have been receiving a steady increase of reports regarding nocturnal bird song. These cases, all in urban settings, were initially thought to be a result of light pollution. Researchers were certain, almost taking it for granted, that the birds were stimulated by the intense light from buildings and street lamps.

Recently, however, better studies proved that light pollution was not the only factor. Instead, it was discovered that the birds were singing at night because they couldn't compete against city noise. Their songs were not being heard, and their energy was wasted.

But how does a diurnal bird manage to sing through the night? Imagine the physiological stress placed on the living organism, an organism whose every instinct has evolved to maximize the returns for each calorie expended. Obviously, the stress of city noise affects other birds, but they have adapted to it differently. Those species have increased the pitch of their songs.

Has the urban robin embarked on a separate evolutionary journey toward a nocturnal species? It is an interesting question.

Fortunately, by that far off in the future there ought to be new technologies and quieter transportation - quieter for us and the birds. Imagine technology that might allow us to preserve the environment and adapt to the changes beyond our cause. Because, as innocuous as this study may seem, man will always be a spiritual creature and in need of the flute-like song of the robin at the break of dawn.

Robert Tougias is a Colchester based birder. He is the author of Birding Western Massachusetts and he is available for slide presentations. You can email him your questions at rtougias@snet.net