For those new to the blog and the Duke Farms Eagle Cam, here are some egg basics. Don't worry if the eggs are left alone for a little while. Bald Eagles' eggs are a dull white or off-white. They may look small in the nest, but they are larger than you might expect. They're roughly the size of lop-sided tennis balls and weigh a quarter of a pound. The egg counts for the Duke Farms nest for the past 11 years have ranged from one to three, arriving three days apart. Last year the adults incubated two eggs. If the Duke Farms eagles incubate a third egg this season, it should arrive on Wednesday in the late afternoon or so. The female keeps the eggs warm most of the time, but the male helps out.
Both adults also turn the eggs from time to time to regulate the temperature and prevent the embryos from sticking to the inside of the shell. To help make it easier to keep the eggs warm, the male and female can develop a brood patch. Conserve Wildlife Foundation describes the patch as a small featherless area on their chest well-supplied with blood vessels. making it possible to transfer heat to their eggs during incubation.
Next Tuesday: Take our bird egg quiz.
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.