If trees could walk

Our ability to move huge, mature trees is fascinating. Now, rather than cut a big old tree down, it seems that campus landscapers just dig 'em up and move 'em around. Not only does this save a tree, it creates an immediate "old" garden--a very new landscape that looks like it's been there for 50 years. Excellent. I wonder if birds nesting in the boughs move down the road with their tree?