Tag Archives: Eggs

Why do bald eagles lay eggs in ice and snow?

Egg-laying Map

Why do the Decorah and Decorah North eagles lay eggs in ice and snow? A lot of you – especially those of you who also watch the Florida eagles – are curious about bald eagle egg timing. Wouldn’t it be better to delay egg-laying until mid-March or early April? We’ll unpack the question by starting with a few facts. An Overview of Bald Eagle Nesting Bald eagles don’t all nest at the same time. In the southeastern United States, especially

Nothing Goes to Waste

March 16, 2021: Ma and Pa Jr. on the nest, Fort St. Vrain, Platteville CO

Xcel Energy’s Fort St. Vrain eagles rode the big storm out last weekend. Despite an astonishing twelve or so inches of snow, Ma kept the eggs covered through most of it. Male and female eagles both incubate eggs, but females usually cover the nest at night and through bad weather. A female eagle’s larger body size and brood patch helps her stay still for longer periods of time and apply more heat to the eggs and young beneath her. Unfortunately,

Eagles, ‘menopause’, and a new mate at Xcel Energy’s Fort St. Vrain plant

Avian Reproductive System, From Handbook of Bird Biology, Second Edition

Has Ma FSV entered ‘menopause’? This blog was going to be focused on eagles and ova, but Elfruler, our original DE lead mod and a long-time chronicler of bald eagle nests, noticed that the male had a band on his right leg, not his left. A new eagle has replaced Pa FSV. If you’d like to learn more about eagles and ova, please read on (TLDR: Ma FSV has not entered menopause). Thanks to Elfruler for her observations and Donna

Courtship, copulation, and other things romantic!

February 5, 2020: Body brushing - Mom and DM2 stand wing to wing in the nest

This is a traditional Valentines Day post for us, but we decided not to wait this year…just in case one of our eagle pairs lays eggs early! Bald eagle courtship Bald eagles are famous for their whirling nuptial flight, but eagle courtship includes any activities that establish a new pair bond or renew an existing one. At our Decorah, Decorah North, and Fort St. Vrain nests, courtship usually begins in early October. Bonded pairs start working on their nests by

How long does it take a bald eagle to lay an egg?

An egg in cross section, modified from Romanoff and Romanoff, 1949

How long does it take a bald eagle to lay an egg? We think that female bald eagles begin laying eggs five to ten days after productive mating begins. In 2018 and 2019, Mom laid her first egg about eleven days after copulation went from casual to frequent…and very determined on Mom’s part.  We’ve often seen female eagles take the lead – beak-biting and footing their mates, loudly vocalizing their intentions, and mounting them! You don’t need to be a

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