Tag Archives: FAQ

What are feathers? What is molt?

Feather Follicle

Eaglets go through two molts and three feather stages in the nest: natal down (and molt), followed by thermal down (and molt), followed by juvenile feathers. As of this blog, the Decorah eaglets are shedding the very last of their natal down and their thermal down is rapidly being replaced by juvenile down and feathers. We thought we would blog a little more about feathers to celebrate!  When we think about feathers, we tend to think about their qualities (light,

Whatta Week! Grabbing, Gulping, Growing Ginormous-sauruses!

April 13, 2019: Whatta Day!

Image and article by Sherri Elliott Gee Whiz, that’s a lot of G-words, but there’s even more as we godparents gather and gaze into the nests with gratitude for all the changes glimpsed gauging their gargantuan G-force growth. Gone are the gentle little grubs … replaced by gangly and sometimes goofy and glorious ginormous-sauruses! We have two nests in Decorah … the original nest at the fish hatchery with Mom Decorah and new male DM2 and their two eaglets D32

What is up with our eagle Moms?

05/09/19: Mom and DM2

We first blogged on this subject on April 30, 2014, but we’re asked about Mom’s behavior every spring. Wondering where the love went? This blog is for you! We’ve had several questions and comments about our eagle Moms. Why are they so demanding? Why are they mad at their mates? Why are they so mean? While I can find snippets of behavior that seem loving to human observers – shared incubation duty, mutual nest defense, and tandem feedings, to name

From bobble heads to eaglets: Natal down, thermal down, and flight feathers!

As the eaglets start to sprout feather cloaks, we’re getting questions about natal down, thermal down, and juvenile feathers. Unless otherwise stated, the information in this blog applies to altricial birds, although most research in this area has been done on precocial and semi-precocial birds like ducks, geese, and cranes. Altricial and precocial birds have some marked differences in pre-hatch follicular development and post-hatch molts.   Does thermal down sprout from natal down pores? Do flight feathers emerge from thermal down

Eaglet Growth and Development: Week Four

Three plumage stages are visible: natal down (head), thermal "down" (grey feathers), and juvenile plumage

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 four in this blog. D32 and D33 are 26 and 23 days old. During week three (fourteen to twenty-one days), the

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