Thursday, June 20, 2013

White-crowned Sparrow

White-crowned Sparrow - Zonotrichia leucophrys

The species name means "white eyebrow," which is apt. The white eyebrow is shared by the White-throated Sparrow, which has also has some yellow at the forward edge of the white stripe.

This White-crowned Sparrow was singing from a perch on a bush behind my garden. These sparrows are regular visitors to the feeding areas in my garden. They feed only on the ground and use their feet to scratch up the surface to reveal sunflower seeds that might be buried under leaves or other debris.

White-crowned Sparrows sing a lot and they likely nest in the shrubs on the hill behind my home. Later in the season I will see lots of newly fledged White-crowned Sparrows at the feeding stations. 
The song of the White-throated Sparrow has been studied more than any other bird. Juvenile males learn songs from their father and also from other males in the vicinity of the nest ("aural environment").

The young male memorizes the song and practices until the song is a precise copy of the model. Then the bird adds novel elements which might or might not remain.

Eventually the bird settles on one (rarely two) song in a personal repertoire. The song usually conforms to the songs in the aural environment.

The dialects in a neighbourhood are shared and become a cultural trait that is passed through generations.

White-crowned Sparrows that nest in areas on the border of two dialects might become "bilingual." 
References

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

Baicich PJ, Harrison CJO. Nests, Eggs, and Nestlings of North American Birds. Princeton UP. 2005.

Beadle D, Rising J. Sparrows of the United States and Canada. Princeton UP. 2003. 

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998.

Sibley David A. The Sibley Guide to Bird Life and Behavior. Alfred A Knopf, Inc. New York. 2001.

Tudge Colin. The Bird. Crown Publishers. New York. 2008.

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