Happy Fri-yay, everyone! DN13 is 35 days old, DN14 is 33 days old, peregrine falcon Zooey has laid three eggs, and the day couldn’t be more beautiful! I loved all of these videos, but don’t miss Cute Close-ups (it shows some really interesting differences between DN13 and DN14), DN14 in for the steal (which casts a nice light on eagle behavior), DNF earning her Wright Brothers Master Pilot of the Year award, or the incredible American Avocets on the Mississippi Flyway!
We’ll be announcing this separately, but I wanted to let everyone know that the Eagle Valley Cam is back! Since the nest tree fell, we have it pointed at a backwater pond for water bird surveys and enjoyment. Watch it here: https://www.raptorresource.org/birdcams/eagle-valley/.
Decorah North Eagles
April 30, 2021: DN13, left. DN14, right! Notice the difference in their feather development!
April 28, 2021: DN14 attempts to self-feed. DN13 interrupts – https://youtu.be/6YNriPR2oy0. Kids! I love how Mr. North – such an experienced eagle Dad! – walked in to break things up at the end of the video.
April 28, 2021: Cute close-ups – https://youtu.be/4QunydgxRaw. The Dynamic Duo are 33 and 31 days old…almost halfway through nest life! Their covert feathers are coming in nicely in tracts down their backs, their talons have gone from clear to taupe (thanks, Robin!) to black, their feet and legs are yellow, and the little poofs of dandelion down are almost gone from their heads! This video has wonderful close-ups of DN13 and DN14, interspersed with some nice shots of the North Valley.
April 29, 2021: DN13, left and DN14, right.
DN14 has less natal down on the top of its head than DN13, even though DN14 is younger. Does this indicate sex? It is complicated! On average, male eaglets leave the nest earlier than female eaglets. But eaglets divide into early and late developers within each sex, and feather emergence is also influenced by nestling order. Based on Gary Bortolotti’s work, both of our eaglets appear to be early developers, with humeral tract feathers that appear on or sooner than 26 days. We first saw DN13’s HU on April 21, when DN13 was 24 days old. DN14’s is clearly visible by April 24, when DN14 was 25 days old. The guessing game continues!
April 26, 2021: DN14 for the steal – https://youtu.be/mFCG1bb5-50. Eagle hierarchies are based primarily on size. DN13 is bigger, so it usually gets what it wants. But DN14 is determined and very persistent! At 18 seconds, it swoops in for the steal, grabbing lunch right out of DN13’s mouth! DN13 appears to think about a response but decides the trouble isn’t worth it!
In ‘The Bald Eagle’, Mark Stahlmaster writes: “When a size difference between two combatants is apparent, the larger foe wins 85% of the contests.” He adds: “Will and determination also affect success rates: a hungry eagle is more likely to win a food fight than a satiated one…In one study, pirating success of hungry birds was 92% compared to 67% for well-fed birds.” This is exactly the interaction we saw here and excellent practice for eagle life outside the nest!
April 26, 2021: A very determined DNF to get raccoon to the nest – https://youtu.be/bBXCRBVV-SQ. An adult raccoon weighs between 7.7 and 20 pounds. If DNF weighs 11 pounds, she could easily be trying to carry her own weight up to the nest. While eagles have been documented carrying loads that weigh around 100% of their body weight, it isn’t easy for them and DNF isn’t soaring or gliding down, she is dead-lifting up. She tries to get the raccoon up to the nest several times, but isn’t able to gain enough lift until a south wind picks up. The resistance lets her gain enough lift without stalling out, and she finally makes it to the nest. I think she deserves a Wright Brothers Master Pilot Award!
Mississippi Flyway
April 25, 2021: American Avocets on the Flyway
April 25, 2021: American Avocet – https://youtu.be/Jc0FgJXoCxA. I apologize for not sharing with you earlier one of the most beautiful things I’ve ever seen here. Also: a perfect look at how American Avocets feed by scything their bills through the water. You can learn more about that here: https://www.allaboutbirds.org/…/American…/lifehistory. I could watch this video all day.
April 24, 2021: Beautiful young BE, Red-Winged Blackbird – https://youtu.be/N4wrla_BTwE. A wonderful reminder of the diversity of birds! Life takes place on an XYZ axis, is filled with genetically distant but physically right-next-to-you cousins, and almost always requires an awesome perch! This video reminds me that we live in the same place but occupy very different maps.
April 23, 2021: Young eagle hunting duck – https://youtu.be/8BRZx50oYlE. I think these might be coots. Check out the behavior – the eagle tries to flush them up, but the coots don’t want to fly for pretty obvious reasons! Instead of flushing, they raft and dive, flying only when the eagle’s attention is on another part of the flock. Two or more eagles could force the flock to rise, but this lone eagle has a tough time.
We’re back to the eagle single/social discussion! When multiple eagles hunt a flock like this, any given eagle stands a better chance of catching a coot, since coots can dive or swim to avoid flushing for only so long. But each eagle stands an equal choice of losing a coot to a hungrier and/or bigger rival. Still, cooperative hunting benefits them overall and they benefit from one another’s presence. I hope this young eagle finds a hunting companion!
Decorah Eagles
April 29, 2021: Mom at the hatchery!
April 29, 2021: Mom taking a break – https://youtu.be/W2TQCElg4ro. What is Mom thinking? Does she miss the hatchery? Will her connection to it fade if she and DM2 don’t move back? Is she showing up to mark her territory? So many questions with no answers yet: just beautiful Mom on the flowering maple trees.
The Raptor Resource Project