We’ve had some hot sultry days this summer, and if you were smart you retreated to a shady spot or went for a swim at a nearby pond.  But what about all those great blue heron nestlings that were sitting in their nests 20-100 feet up in a  tree, often in full sun?  Sure, their nest tree may be surrounded by water if it is a snag in a beaver flowage, but that water is completely inaccessible to a nestling who takes around 80 days to learn how to fly.  How do they keep cool on those 90+ degree days?  Like humans, birds rely on evaporative cooling to release heat; however, birds do not have swea