Bird Watching: An unexpected observation of Raven nesting., 1 by Grasmussen

Grasmussen wrote:
At the end of March 2007 I became aware a pair of Common Ravens were building a nest behind the community garden plots, on C street, in Chester Valley, down town Anchorage, AK. I could watch the nest from my living room window, until the leaves came out on the trees. I expected the Ravens to use the same nest last year, 2008. But, the Ravens moved the nest about 500 feet northwest, to the center of the largest stand of dens trees in this section of the Chester Creek Green-belt. When I say moved the nest, I mean stick by stick, they moved the nest. Every last peace of the 2007 nest was removed in 2008. Yesterday, March 24, 2009, observed the Ravens have nearly completed a nest in the exact same place it was removed from last year! Ravens are territorial when nesting. This pair claims an area about a mile radius around the nest. There is no doubt in my mind it has been the same pair, all three years.

I’m puzzled by these observations. Has anyone else observed similar behavior, or any comments?

Gary