What the pigeon in the planter on my porch and the eagle on the nest in the Decorah Fish Hatchery Eaglecam have in common:  settling down on the nest with exquisite care. The eggs or baby eagles are  ever so tenderly covered and cocooned.  The adult bird’s belly feathers look as soft and fringy as the underside of a cumulus cloud.  The pigeon even has cloud-bottom-gray feathers;  the eagle has brown underfeathers or, toward the tail,  pure white.