Fort St. Vrain Eagles and Blogs

Eaglet Growth and Development: Week One

March 26, 2021: DN13 eats breakfast!

We’re writing a series of blogs about the first few weeks of an eaglet’s life. An eaglet spends roughly 75 to 80 days in the nest. For about the first half, it grows and gains weight. For about the second half, it grows flight feathers and starts developing the skills it will need post-fledge. We will focus on week one in this blog. What can we expect in the first week following hatching? Like humans, growing eaglets have developmental milestones.

First Egg at Fort St. Vrain!

This photo by Lanie Burritt shows Ma & Pa's huge nest, one of our FSV eagles perched to the right of it, the Rocky Mountains and geese flying by.

Congratulations Ma and Pa FSV! Post by Lanie Elaine Tregenza Burritt The first egg of the season arrived at the Fort St. Vrain nest on Thursday, March 3 at 5:09 pm. Bob Anderson, founder of RRP, and partner Xcel Energy installed a cam back in 2003; this nest has seen 44 successful hatches. Ma has historically laid eggs mid to late February, but last year the first egg arrived on March 4. Watchers speculate this may have had something to

Peek inside a bald eagle egg: 11 days!

Chicken embryos roughly 25% of the way to hatch

What do embryonic eagles look they look like as they develop and grow inside their eggs? Dr. Peter Sharpe from the Institute for Wildlife Studies developed a table of bald eagle embryonic development based on work done by Hamburger and Hamilton (1951). While not all bald eagle eggs hatch in 35 days, the stages of development look something like this… What happens between the third and the 11th day? When we last touched on the topic, our embryonic eagle had

What is a brood patch?

March 30, 2018: Mrs. North's brood patch

Daylight length, or photoperiod, strongly influences hormone production in birds. In the northern hemisphere, our story begins shortly after the winter solstice in December. As daylight length increases, a cascade of hormones causes birds’ gonads to swell in preparation for reproduction, egg-laying, and incubation. In this blog, we’ll discuss the role the brood patch plays in incubation and determining clutch size. How do bald eagles keep their eggs warm in subzero temperatures? They apply heat via a special area of

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

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