In addition to what others have pointed out related to nestbuilding, there are also bird species that do not build nests. Instead, they have come up with a variety of potential solutions. Penguins use their feet. Others steal existing nests that other species have built. Still others simply stick their eggs in with those of some other species and let the surrogate raise their young. And yet other species just dump the eggs on the ground. Some, such as the Osprey, eagle and many owls, build a nest that they return to year after year. They modify and repair it but continue to use the same basic structure as long as it's available.
Aslan is not a Tame Lion
™ Version 4.2