One of the most frequently asked questions on the WVEC web cam chat is “how common is it for bald eagles to lay three eggs?”
Bald eagle surveys have been conducted in Virginia since 1977 when Dr. Mitchell Byrd at the College of William and Mary in Williamsburg and the Virginia Department of Game and Inland Fisheries (VDGIF) initiated the first systematic survey. Those surveys have been completed every year and beginning in 1991 have been conducted by The Center for Conservation Biology at the College of William and Mary with funding from the Wildlife Diversity Program of VDGIF. One of the principal objectives of the survey is to determine bald eagle productivity. Breeding activity and productivity is determined by two aerial flights. The first in late February to mid-March locates active nests. A second flight from late April to mid-May checks for nest productivity.
The numbers from the 2008 survey will give a measure of bald eagle productivity in Virginia. This is only one year and statistics over a period of time could be somewhat different. In 2008 there were 557 known active bald eagle nests in Virginia. Productivity in 15 (3%) of those nests is not known because vegetation was too dense to see into the nests. Of the remaning nests 97 produced no chicks (17%), 107 produced one chick (19%), 263 produced two chicks (47%), and 76 produced three chicks (14%).
2010 is actually the 5th year for the adults at Norfolk Botanical Garden to produce 3 eggs. In 2006, 2007 and 2009 3 eaglets successfully fledged. In 2008 3 eggs were layed but 2 were broken and only one egg hatched. That eaglet developed avian pox and remains at the Wildlife Center of Virginia. So, of the 7 years at NBG these adults have produced 3 eggs 5 times. Well above average.