Volume 2 Issue 10
July 2022
Pam Narney pnarney@gmail.com
A Step Into Space
July 10 was an ordinary morning. Then Cassidy left the nest. He flew like a natural. He made a few circuits around the nest and returned, sticking the landing. A perfect 10! The earth did not move and thunderous applause was absent. This first flight is quite an accomplishment for those of us who are earthbound.
His first flight was well within the approximate age for fledging of 56 days old. The time-frame for first Osprey flights is 50 to 55 days after birth for migrating Osprey (Poole). Our abnormally wet weather might have slowed him down. Having fledged, Cassidy is now a juvenile Osprey.
Male or Female?
Even though Cassidy is smaller than Carla, is more aerodynamically built than Carla, has only a few spots on his neck rather than the many Carla has, and flies like a demon--all male characteristics--Cassidy is developing a necklace. A typically female trait. It is difficult to determine the sex of a juvenile Osprey until it is fully grown, but some characteristics develop early.
Carl, now Carla, has a neck band developing and is larger than Cassidy, both female ID traits. She has not flown on schedule. Her schedule would have been two or three days after Cassidy. Her expected flight dates were July 12 or 13.
Developmental Delays
Why hasn’t Carla flown yet?
Is this delay brought on by lack of food at a critical point or just the natural progression of a fledgling’s life?
Food stress is a problem this year shown by pecking from Cassidy. “Well fed juveniles seldom peck each other” (Poole). The lack of food must be delaying her development. Searching for “Osprey food provisioning and body development” got few Google hits, but the connection is obvious.
Lack of food at a critical growth period slowed Carla’s physical development of muscle and wings.
What are her instincts telling her? What does she think when she is alone in the nest while Mom and Cassidy gracefully come and go?
Each day we wait.
And each day Carla is the lone bird in the nest, begging for food, although not much food is coming. Surely hunger will force Carla from the nest.
July 17
Cassidy flew seven long days ago. Cassidy’s wing exercising--flapping, hopping and jumping--started on June 19.
Carla did not exercise her wings seriously until July 5th.
She does a side step, side step, hop but she doesn’t do much flapping or hovering. Carla is not doing many sets of wing strengthening. When she does, she tires quickly and flops down into the nest.
Carla still holds her wings down about half of the time, illustrating that her wing/bone /muscle structure is not fully developed. This is another sign of food stress.
Following the normal developmental progression for a juvenile, Carla should have flown a few days after Cassidy did.
The Accidental Aviatrix
Ready or not, one errant gust of wind will send her out of the nest. Most Osprey first flights seem accidental.
Every day we watch, expecting Carla to fly, and every day we are disappointed.
What if she does not fly? Osprey observers worry. Nature usually triumphs.
Carla must be disappointed too because Cassidy flies around the area, in and out of the nest with ease.
Mom and Dad are bringing fewer fish so the juveniles are hungry all the time. We haven’t seen George in quite a while. What happened to George? He should not have migrated this early but…
Often when Mom has a fish she flies around over the nest, taunting Carla. “Come fly with me!”
Migration Plan
Parents reduce the food supply to urge the kids to fly and fish for themselves. This is part of Osprey evolution. If the juveniles do not learn to fly and fish, they will not have a successful migration. The juveniles will leave the Colonial Beach area sometime between August 15 and September 15. They have a month or two to learn, observe, get stronger, practice and perfect their flying and fishing techniques.
The juveniles can’t rely on their parents during migration. Ospreys migrate alone. Fishing and flying are the only resources that will keep them alive.
More Food Stress
Even with her larger size, Carla still defers to Cassidy when food arrives and waits until Cassidy is finished feeding. Those head peckings made a lasting impression. Peckings have decreased, but all Cassidy has to do is approach Carla when fish are involved, and Carla, even though she is larger, backs off and crouches away.
See “Nature Red in Tooth and Claw”
For details on food stress and sibling rivalry.
July 19
Nine days after Cassidy flew, Carla flies while we are not home. I missed it! Did a gust of wind push her out of the nest or did she just go? Our neighbor reported the flight. Carla landed on his roof and stayed there for quite a long time.
See “First Flights and Sometime Landings”
For a closer look at Osprey landing attempts.
July 20
We came home to the sight of an Osprey on our tv satellite dish. It was a hot day.
Carla stayed on the dish, then on the roof, then moved to the other side of the roof. Since it resembles a branch, the dish must appeal to her. The broad expanse of roof reassures her.
Eventually she tried to return to the nest. Instead of approaching below the nest at speed, then moving up, stalling and dropping into the nest, she hovers and tries to lower herself down slowly. She knows she can hover because she used that maneuver to take off. The wind blows her off course.
She makes another pass at the nest and repeats the hovering approach. Carla has not learned that zero air speed and zero altitude combined make an efficient landing. She is flying like a helicopter instead of a fixed wing airplane.
There is very little research on the developmental stages of Osprey juveniles. It’s too intrusive to catch, measure, and weigh them at regular intervals. Even though some Osprey are used to having humans around, many are upset by human contact.
July 22
Hungry Again
Mom delivers a fish. Cassidy flies fast into the nest and grabs the fish. After a while Carla lands. She faces away from Cassidy while he eats. Cassidy holds the fish firmly with his foot.
Fortunately, Cassidy has not yet developed the skill of grabbing the fish and flying off with it to a perch.
Yes, he has! There goes Cassidy with the fish. Carla misses another meal.
No breakfast for Carla today.
She must be very hungry now and frustrated.
Catching Fish
If it took Carla seven extra days to fly, how many more days will it take her to catch her own fish?
The speed at which the juveniles develop skills is amazing, but then they have precious little time to learn all they can about life. In two to four weeks they will migrate by themselves to South America.
Cassidy flies into the nest with his own fish. Where or how he caught it, no one knows. Some Osprey can catch their own fish two to three days after fledging.
We think we know so much about Ospreys because they live in the open close to us, but there is so much more that we do not know.
Ospreycam?
Could we put miniature kitty cams with GPS on the heads of each member of an Osprey family? We could find out where they go to fish, who goes with them, do they go alone? Do they fish where Dad does? Where are there favorite perching spots? How many times did they try before they caught their own fish?
“Inquiring minds want to know.”
What must a dive feel like for the first time: head down, body turned into an arrow plummeting from as high as 130 feet directly into the water and grabbing a fish. Then lifting that live fighting fish out of the water and taking it to a safe place to feed.
Nature is amazing!!
Now is Osprey time in Colonial Beach. The skies are full of Osprey playing, practicing, fishing and generally having a good time.
ENJOY the view!!
By the end of August or the middle of September, these juveniles will migrate.
Who will go first and how long it will take them all to leave?