Fort St. Vrain Eagles and Blogs

Peek inside a bald eagle egg: 24 days!

Development of an avian embryo

There are two eagle eggs in Decorah trout hatchery nest N1. DH1 is about 27 days old and DH2 is about 25 days old. What do they look like? Let’s take a peek!  What do embyronic 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 this animation uses a chicken

Monday. March 13: NestFlix and News

March 8, 2023: Mr. North at the North Nest. He is an awesome, dedicated father and is doing his best to care for the egg.

Ma FSV laid her third egg at Xcel Energy’s Fort St. Vrain nest on Thursday, March 8, which brings the total number of eggs in our nests to six: three at FSV, two in Decorah, and one at Decorah North. DNF and Mr. North’s lone egg is 21 days old, HM and HD’s two eggs are 16 and 13 days old, and Ma and Pa Jrs eggs are eleven, eight, and four days old! Here’s a peek at what’s going

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

March 6, 2023: What are we looking forward to this week?

March 6, 2023: A Canada Goose at N2B

Another Egg for Ma FSV? As of this post, we have one egg at Decorah North (hatch estimated on or around March 28), two eggs in Decorah (hatch estimated on or around April 4), and two eggs at Fort St. Vrain (hatch estimated on or around April 10). Ma usually lays three eggs, so it’s possible she could lay again on March 9th. Are the geese going to lay eggs again? We’ve seen them checking out N2B, but HD doesn’t

First Egg for Xcel Energy’s Fort St. Vrain Eagles!

March 3, 2023: Pa FSV with his egg at Xcel Energy's Fort St. Vrain nest.

Congratulations to Ma FSV and her mate Pa Junior! Ma laid her first egg of 2023 at Xcel Energy’s Fort St. Vrain nest in Platteville, Colorado yesterday at 6:18 PM. Ma usually lays her second egg three days after her first, so we’re looking forward to another egg on March 5! The first hatchling will be FSV47: the 47th eaglet produced in this nest since we started counting in 2006. To watch the Xcel Energy Fort St. Vrain eagles, follow

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

February 13, 2023: What are we looking forward to this week?

February 13, 2023: Mr. North and DNF are getting their egg cup ready!

What are we looking forward to for the week of February 13? Tick-tock egg-clock, everybody…we’re getting egg-cited! Eggs at Decorah North. DNF laid her first egg on February 16th in 2021 and 2022. Will we have a three-peat this year? It seems possible, especially since the two appear to be working on an egg cup: https://youtu.be/ODY5bU10M6s (we get a nice view of the cup at around one minute in). HM and HD have finally gotten their groove on! We don’t

Bald eagle mating: Courtship, bonding, copulation, and other things romantic!

February 8, 2023: HD and HM copulate in the nest.

Love is in the nest! This is a traditional Valentines Day post for us, but after HD and HM copulated this morning, we thought we would post it in celebration. 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

January 30, 2023: NestFlix and News from Decorah, Decorah North, and Fort St. Vrain

January 26, 2023: HM and HD.

We saw a lot of visiting eagles arrive late last week as subzero temperatures and storms pushed eagles into northeast Iowa. Many bald eagles winter in the same place every year, but others behave more like irruptive migrants as they wander the landscape in search of open water and easily available food. Extremely cold weather and serious snowfall push wanderers south – much to the chagrin of residents who aren’t excited about hungry visitors near their nests! The interlopers kept

How do eagles stay warm in cold weather?

January 23, 2023: HD sports eye-cicles on a frosty morning in Decorah. An icy fog left everything coated with frost

Each species experiences the world differently and eagles have capacities that are far different from ours. How do Bald Eagles survive an Iowa winter without adaptive clothing and central heat? A cold January morning coated our eagles in frost and left watchers wondering how Bald Eagles survive an Iowa winter. In general, wintering animals – including humans – need to retain body heat, stay dry, and take in enough calories to support winter’s increased energy demands. We humans put on

« Older Entries