The two most dramatic parts of a Bald Eagle nesting season are the arrival of the eggs (typically three days apart) and when the chicks begin to hatch (typically 35 days later). But for sheer anxiety, it's tough to top those stretches when the egg (or eggs) have been left uncovered for seemingly too long on a cold day. On Friday, for example, the first egg (above) was left alone for roughly a half hour, and the Ustream comments reflected all sorts of concerns, from predators to unheated eggs. Similarly, last February webcam viewers grew worried when neither adult eagle incubated the eggs for a couple of hours, and voiced their fears on the Ustream message board. Were the eggs -- and the parents -- OK?
As it turned out, everyone was fine. As Thom Almendinger, Duke Farms Director of Natural Resources aptly put it last year: "This is an experienced pair that has successfully hatched 19 or 20 of the 21 eggs it has produced. The adults instinctively know to sit on the eggs when they need heat and get off them when they need to be cooled. Kathy Clark, a wildlife biologist for the N.J. Endangered and Nongame Species Program, has explained it this way: Eggs are okay getting chilled for the first few days, before there is much development. They cant freeze, though, without some permanent damage to the embryo. One other thing to keep in mind: Just because an adult eagle is not visible on the nest, that does not mean it's far away. It simply means that the eagle is not in camera range. I have seen the Ridgefield Park Bald Eagles perch on branches near the nest, keeping watch, when the eggs are in the nest alone. In short, this is wild nature. Nothing is certain, and anything can happen. There will always be something to worry about if you think hard enough, but just try to appreciate this little journey for as long as it lasts.
Tuesday: Egg Basics
Eagle questions? E-mail Jim at firstname.lastname@example.org Some may be used in future posts.
Jim Wright writes The Bird Watcher column for The Record. He is the author of four photography-driven books about natural areas, including the New Jersey Meadowlands, and Pennsylvanias Hawk Mountain.