Jordan Lake: Time is of the essence when it is cold and the parent eagles need to trade places on the eggs. Eggs left uncovered in the cold winter air will die if left uncovered for more than 2 minutes. Mom Kate was on the egg(s) when I arrived. 2 hours later she started calling and Dad Petruchio arrived. Kate jumped up on the branch next to Petruchio (she is closest to the trunk). They glanced down at their eggs. Dad Petruchio jumped down into the nest and settled onto the eggs and Mom Kate left for some flight time. The whole exchange took 38 seconds. This is a critical time for the eggs and then for chicks up to 2 weeks of age because any disturbance by humans can cause the parents to leave the eggs or chicks exposed too long and the disturbance could quickly become fatal to the new family.