January 22, 2025: Welcome back, DNF and Mr. North and Mr. and Mrs. T!

It’s (practically) a tropical heatwave! While eagles are well-suited to snow and cold, they tend to respond to sub-zero temps by reducing their activity, which is exactly what we saw through this week’s polar plunge! After bringing sticks in on Saturday, the Norths ceased nestorations until about 11:00AM this morning, when DNF flew into the North nest with a talonful of grass. Mr. North quickly joined her and the two spread nesting material, dug and scraped, checked out the nest bowl, and added crib rails. Slow down when he flies in and you’ll see nest material preceding his arrival!

How cold did it get during the polar plunge? A regional weather station reported a low of -23.1F. The temperature dropped below 0F at about 11PM on Saturday and did not break into positive territory again until about 1:30PM on Tuesday. That’s cold!

January 25, 2025: A look at the polar plunge!
January 25, 2025: A look at the polar plunge. Okay, there might have been a few moments the temperature rose above zero degrees, but it wasn’t much and didn’t last long!

Tick-tock, egg clock! Last year, DNF laid her first egg on February 15. While experienced eagles in long-term relationships usually lay around the same date every year, warm moist weather can bring eggs on the earlier side, and cold dry weather can push them a little later. Copulation really ramped up on January 28 last year, going from once in a while to more than once day almost overnight! We’ll write more about that tomorrow, but we’ll be looking for DNF and Mr. North to start getting very busy late this week or early next week.

Trempealeau Eagles

Like DNF and Mr. North, Mr. and Mrs. T took a break from nestorations. But they returned this afternoon and got right back to work! I’m curious about where they went. We saw several Bald Eagles nestled in the lee of hatchery rock on Monday. Perhaps the two sought a tree or tangle a little closer to the wind shadow of the hills behind their nest.

Last year, Mrs. T laid her first egg on Monday, February 25. But we think it might have been Mr. T’s first year there based on his behavior. He had the instincts to care for young but lacked experience and knowledge. First-time parenthood isn’t easy for us or them! We’re looking forward to seeing how he does this year and whether or not their egg laying schedule moves forward.

Decorah Eagles: HM and HD

We think we know about where HD and HM are nesting, so we’ll be keeping an eye on them. I mentioned that the two had visitors on January 20, so I wanted to share the video. It’s not Eagle Valley or Lock and Dam 18, but it is more eagles than we usually see here. Our camera operators also spotted a copulation today, so the two are definitely on track for eggs!

Thanks so much to our awesome camera operators and video makers for finding such special moments, and to you for watching, sharing, learning, and especially for caring!

Odds and Ends

There is some interesting habitat/bio-hacking work going on in Wisconsin right now. Here’s a really cool example: https://www.minnpost.com/other-nonprofit-media/2025/01/an-ecosystem-engineers-vision-mock-beaver-dams-to-restore-wisconsin-wetlands/. Hoffman, 60, hopes the BDAs (Beaver Dam Analogs), which could pool up to 1.7 acre-feet of water during floods, improve water quality, stabilize eroded stream banks and enhance wildlife habitat. Most of all, he seeks to trailblaze a path through the state’s onerous dam-permitting process so other Wisconsin landowners can follow in his footsteps.