Friday, May 24, 2013

Robin song in the urban jungle starts really early

The best part of spring for me is waking up to bird song. But you have to wonder why the American Robin and Northern Cardinal start singing at dawn. Are they just early birds or perhaps think this the best time to sing a solo?

A recent article by Mark Blazis pondered the advantages of the early bird. He and ornithologist Andrew Vitz theorized that many female songbirds lay their eggs in early morning and that a male sings at that time to reinforce the bond with the female, while simultaneously dissuading other males from jumping into the nest.

Research by biologist Mark W. Miller also found that in 1929 the first robin songs began about 45 minutes before sunrise, but 84 years later with our neighborhoods flooded in artificial light, robins tended to break their silence more than an hour earlier.

I was watching a robin furiously gathering mud and dried plant litter at the edge of the drainage ditch at the Wild Birds Unlimited - East Lansing store yesterday. Females build cup-shaped nests from long coarse grass, twigs, paper, and feathers woven together and then line the inner bowl with mud, smearing it with their chest and later adding fine grass or other soft material to cushion the eggs.

In Michigan, American Robins breed once or twice yearly. The breeding season extends from April through July. Blazis writes that sex and singing are inextricably connected and once a robin’s second clutch has hatched, romantic courtship will be replaced largely by parental duties. Then the early morning passionate birdsong will drop dramatically.

But don’t worry, just as the robins end their courtship the American Goldfinches begin theirs!

Sources:
Outdoors: Predawn bird songs fading soon by Mark Blazis http://ning.it/LT6Xvk
American robin song by Patterson Clark http://goo.gl/ERk2f

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