Fort St. Vrain Eagles and Blogs

Bald Eagles, Eggs and Cold Weather

The eggs are warmed and protected by their parents’ bodies and the insulation beneath and around them.

Cold weather often raises concerns among Bald Eagle watchers. Will their favorite eagles keep their eggs warm and dry in sub-zero temperatures and snow? Eagles don’t have central heating or electric blankets, but they have everything they need to incubate their eggs through the worst a Midwestern winter can throw at them: meticulously built nests that aid incubation and withstand winter’s chill, highly vascularized brood patches that transfer body heat directly to their eggs, and remarkably robust eggs.  In short:

February 10, 2025: NestFlix and News from Decorah North and Fort St. Vrain!

February 10, 2025: Fly like an eagle! Mr. North shows off his long wings and unparalleled aviation skills

Put up your feet and take a deep breath…it’s time for NestFlix! Today’s Diction-aerie word is ‘eggnant’: a female eagle’s condition immediately prior to laying eggs. Our bald eagle Moms are shifting fat to their brood patches and retaining water as their egg follicles swell and mature. We’re planning to begin egg watch on Friday, but we’ll also be watching for DNF, Mrs. T, and Ma FSV to begin loafing around the nest and ‘practice’ laying as eggs draw nearer!

February 3, 2025: Nestflix and News from Trempealeau, Fort St. Vrain, and Decorah!

February 2, 2025: Mr. T and his messy beak!

Put up your feet and relax – it’s time for NestFlix! Today, we have videos from Trempealeau and Fort St. Vrain, and an Odds and Ends about getting involved with nature in your community! Tick-tock, egg-clock: if DNF sticks to her usual schedule, we’ll see our first egg in just 13 days or so. I hope you are as eggcited as we are! Time flies when you’re watching eagles and falcons… Trempealeau Eagles February 3, 2025: Love is in the

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

When will our eagles lay eggs?

January 26, 2025: Mr. North and DNF duetting

When will the Decorah North, Trempealeau, and Fort St. Vrain eagles begin laying eggs? Mark your calendars as follows! It looks like the lead-up to eggs has started at the North nest. Mr. North and DNF have copulated almost every day since January 24 and DNF was very interested on the one day they didn’t. This is very similar to 2024, which again, puts egg number one around February 15. We’re also seeing solicitation, footing, and duetting. More on eagle

How do Bald 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? After a very warm week, temperatures plummeted on Saturday! When I jumped into my car to begin our Golden Eagle Survey, it was 25 degrees. By the time I got home late Saturday night, it was 5 degrees and the temperature was dropping fast! I checked our camera operators’ logs,

January 14, 2025: NestFlix and News from Decorah North and Fort St. Vrain

January 11, 2025: A stunning overhead fly-in by Mr. North, who expertly drops into the nest.

Kick up your feet, grab a favorite snack – maybe some leftover Christmas cookies? – and get ready for NestFlix! We have videos from Decorah North and Fort St. Vrain! Stay warm, everybirdie…egglets will be here before we know it! Decorah North Eagles January 13, 2025: The Norths visit the nest, looking really cozy – https://youtu.be/rOBeNDp1wBM?si=FISXol2PtxPiJHZI. The North Nest is looking good! I liked this whole video, but I especially enjoyed the overhead view beginning at about 1:11, Mr. North’s

January 10, 2025: The Week in Bald Eagles!

January 9, 2025: DNF caught a nice trout for breakfast - https://youtu.be/X2GebRWdrYo?si=6g5qKAufUzY11AcH. While Bald Eagles eat a wide variety of food, their favorite thing is fish! Although the species change, fish make up from 68 to 88% of meals at our nests. We tend to see whatever is most common and easiest to catch: trout and sucker at the North nest and sucker, carp, and trout at Fort St. Vrain. We're still working on fish ID in Trempealeau, but we've seen gar come into the nest, reflecting its location on the Mississippi River. To learn more about what our eagles eat, follow this link: https://www.raptorresource.org/tag/menu/

Happy Fri-yay, everyone! Welcome to the week in Bald Eagles! 🦅 This week, the Norths perfected their nestorations, ramped up their courtship – albeit in a very eagle way – and enjoyed some trout tartare, the Fort St. Vrain Eagles shoveled snow and fed themselves and the local magpies, the Trempealeau Eagles showed off their magnificent river views, and HM and HD hosted some visitors. Is your egg clock ticking yet? If the Decorah North and Fort St. Vrain Eagles

January 6, 2025: Building and Beaking!

January 6, 2025: Building and Beaking at the North nest! https://youtu.be/5ZM5Pyfbvio?si=w9JWDXYzdExnakkL. It’s a great time to watch DNF and Mr. North flirt – albeit in a very eagle way! – as things ramp up. Look for beaking, body brushing, gentle nibbling, footing, and side-by-side perching. More on eagle courtship and bonding here: https://www.raptorresource.org/.../bald-eagle-mating

What are we looking forward to this week? Mr. North and DNF are busy testing and improving their new digs as they pile on husks, stalks, and grass. Shag carpets are back, baby! We recorded our first copulation of the season on December 7th, although we don’t really expect things to ramp up until the last week of January. But it’s a great time to watch DNF and Mr. North flirt – albeit in a very eagle way! – as

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