Raptor Resource Project Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Bald Eagles Fact of the Day  (Read 18024 times)

Iriscats

  • Moderator
  • Newbie
  • *****
  • Posts: 27
Re: Bald Eagles Fact of the Day
« Reply #30 on: April 28, 2020, 06:16:34 PM »

for April 29,2020

Within the first month they will begin to cast pellets which are indigestible parts of prey (some bones, fur, feathers and scales) which are formed and compacted in their gizzards.  We will also notice them grasping with their talons, and may attempt to peck at food in the nest even though they are not ready to self feed yet. They are already grabbing at food in their parent's beak, not waiting to be fed, but snatching and gulping enormous chunks of food.

pyrmum1

  • Moderator
  • Newbie
  • *****
  • Posts: 16
Re: Bald Eagles Fact of the Day
« Reply #31 on: April 29, 2020, 07:54:35 AM »

A bald eagle's feathers are important for flight, regulating body temperature, & are useful for territorial, social & courtship displays. Feathers also help keep certain areas of the body clean from debris & transmit information to nerve receptors in the skin (e.g. wind currents).  Bald eagles have approximately 7,000 feathers.  The feathers of a bald eagle weigh twice as much as their skeleton (which weighs about half a pound).  Thirty bald eagle's feathers weigh about the same as a penny (.088 ounces). 

Feathers protect an eagle from the cold and sun by trapping layers of air.  A bald eagle will change the position of the feathers by ruffling & rotating them. This action aids in maintaining their body temperature & the air pockets are opened to the air or drawn together to reduce the insulating effect.  Its feathers allow bald eagles to live in extremely cold environments.
« Last Edit: April 29, 2020, 04:14:03 PM by pyrmum1 »

tulsaducati

  • Moderator
  • Jr. Member
  • *****
  • Posts: 80
  • Spread the Word: Lead-free hunting and fishing
Re: Bald Eagles Fact of the Day
« Reply #32 on: April 30, 2020, 08:45:57 AM »

April 30, 2020
Bald eagles keep their feathers in good condition by preening, which involves removing dirt, smoothing, and distributing oil that comes from a gland near the base of the tail called the uropygial or preen gland. Ornithologist Frank Gill describes it as a rich oil composed of waxes, fatty acids, fat and water.  The gland has pores that secrete the oily substance.  Preening is rubbing the head and bill over the gland pores, redistributing the oil to feathers, legs and feet. Dr. Ford states, "It was once thought that applying oil to the feathers helped make them waterproof and helped in the production of Vitamin D.  We now know that the feathers are naturally waterproof by microscopic structure and that Vitamin D is not produced from the preen oil photo-degrading on the feathers. The oil most likely acts as a conditioner to moisturize and protect the proteins in the feathers to keep them pliable."
Please join us in our campaign to GET THE LEAD OUT. Together we can make the world a safer place for Bald Eagles and all wild life. We need you, THEY need you!
https://www.biologicaldiversity.org/campaigns/get_the_lead_out/index.html

Iriscats

  • Moderator
  • Newbie
  • *****
  • Posts: 27
Re: Bald Eagles Fact of the Day
« Reply #33 on: April 30, 2020, 07:55:31 PM »

May 1, 2020

Pin feathers continue to develop. They are also known as blood feathers because they are connected to the blood supply which emerges from the skin's feather follicle and allows the feathers to grow. The emerging feathers will initially be surrounded by heavy layers of down. The dark feathers are arranged in tracts beginning with the head (capital) and back (dorsal) tracts. The (ventra)l or belly feathers are the last group to appear. Males develop plumage earlier than females. Their feet and eyes are growing fast and nearly full size during this stage
« Last Edit: April 30, 2020, 09:03:29 PM by Iriscats »

cwellsla

  • Moderator
  • Full Member
  • *****
  • Posts: 207
Re: Bald Eagles Fact of the Day
« Reply #34 on: May 01, 2020, 11:52:03 PM »

May 2, 2020

Juvenile flight feathers start growing at about 27 days, although feather growth does not overtake structural growth until thirty-five to forty days after hatch. The flight feathers of the wings are called remiges and are of two kinds: primaries and secondaries. Primaries are 10 in number and are attached from each wrist to the wing tip. They aid in providing forward lift or thrust in flight and help in stability and maneuverability during flight. Secondary flight feathers, or secondaries, are mid-wing, and are 16 in number. In bald eagles, they make up most of the body's surface area, going from the wrist to the elbow and aid in vertical lift. When bald eagles have attained their mature size, their wing feathers will extend to within an inch of the tip of their tail feathers.


You can clearly see the primaries and secondaries at work in this slow motion video:
https://youtu.be/thEkFMaB5CA?t=33
« Last Edit: May 02, 2020, 07:11:36 AM by cwellsla »
All you need is love.
Lennon-McCartney

glogdog

  • Moderator
  • Hero Member
  • *****
  • Posts: 4146
  • And He will raise you up on Eagles' wings!
Re: Bald Eagles Fact of the Day
« Reply #35 on: May 03, 2020, 07:16:37 AM »

One type of learned behavior is Voluntary learning.  It produces voluntary conscious responses.  They are not automatic and not necessarily immediate.  Voluntary learning includes insight which assumes the bird has knowledge or understanding of a situation.  Insight can come from watching parents and siblings and then joining in.  An example would be a young eaglet watching its parents de-fur or de-feather prey.  At some point the eaglet will attempt to do that on its own.  Insight learning is relatively permanent.  Once knowledge is gained it can't be unlearned.
glogdog

eaglesrock29

  • Moderator
  • Hero Member
  • *****
  • Posts: 899
  • Hope is the thing with feathers ... Dickinson
Re: Bald Eagles Fact of the Day
« Reply #36 on: May 03, 2020, 07:43:08 AM »

D34 and D35 are four weeks old today and it's just a few more days for D36!  At four weeks, the eaglets are grasping with their talons. They may attempt to peck at food, although they are not yet ready to self-feed (hmm, what to do with those feet lol). 

They may grab at food in their parent's beak, not waiting to be fed, while snatching and gulping enormous chunks of food.  Within the first month, they have begun to cast pellets which are indigestible parts of prey (some bones, fur, feathers and scales).   Pellets are formed and compacted in their gizzards.  Think about those fish tails they have been consuming  :)

Males are developing plumage earlier than females.  Male eaglets may gain about 3.6 oz per day, while females may gain about 4.59 oz per day.  After 20-30 days, the weights of the two sexes begin to diverge or separate and sexual size dimorphism begins to appear.  The quicker rate of female weight growth results in their lifelong difference in size. 
« Last Edit: May 03, 2020, 03:38:45 PM by eaglesrock29 »
"When a storm is coming, all other birds seek shelter. The eagle alone avoids the storm by flying above it. So, in the storms of life may your heart be like an eagle's and soar above." - Anonymous

pyrmum1

  • Moderator
  • Newbie
  • *****
  • Posts: 16
Re: Bald Eagles Fact of the Day
« Reply #37 on: May 04, 2020, 07:45:39 AM »

Frank Gill says the avian heart is approximately 41% larger than a mammal's heart of similar size.  The avian heart can also pump about 7 times as much blood as a human heart. The heart of a bald eagle has 4 chambers & is very similar to a human heart except that the eagle's aorta bends to the right instead of to the left as in humans.  The avian heart rate varies with the size of the bird.  An eagle's heart rate may range between 120 beats per minute (BPM) for a calm bird to 300 BPM for an excited bird. The heart rate can jump from 120 to 300 instantly when suddenly excited. Like other birds, their heart rate is generally higher than a mammal of the same size.
« Last Edit: May 04, 2020, 07:51:18 AM by pyrmum1 »

jfrancl

  • Moderator
  • Hero Member
  • *****
  • Posts: 1233
  • Educating is key to ending lead poisoning
Re: Bald Eagles Fact of the Day
« Reply #38 on: May 04, 2020, 07:47:09 AM »

We are often asked what kind of tree the nest is in. N2B was built in a male Cottonwood tree. The scientific name for the cottonwood is Populus deltoides.  The common name is Eastern Cottonwood.  The female Cottonwood produces cotton-like seeds but both male and female trees grow heart shaped leaves. The cottonwood is classified as a hardwood although the wood is lightweight and rather soft.  The average tree is 60-100 feet tall with a 60-100 foot canopy spread. They grow best on moist, well-drained sands or silts near streams.

N1 and N2 were also constructed in male Cottonwood trees.
Please join us in our campaign to GET THE LEAD OUT. Together we can make the world a safer place for Bald Eagles and all wild life. We need you, THEY need you!
http://raptorresource.org/forum/index.php/topic,765.0.html

smileawhile

  • Moderator
  • Newbie
  • *****
  • Posts: 46
Re: Bald Eagles Fact of the Day
« Reply #39 on: May 04, 2020, 08:39:32 PM »

Post for May 5

Coming to Terms!
Digitigrade - animal or bird that walks on its toes (digits) as opposed to -
Plantigrade - foot flat on the ground (humans).
Eagles are digitigrade (what a great vocabulary word!).  We see that starting in week 4 our Decorah eaglets are gaining the muscle strength to stand.  The nest is certainly not a very firm, stable surface to practise walking but the challenge will actually help them strengthen those leg muscles.  This will enable them to "prance" about on those huge toes to explore their beautiful (eaglethood) home high up in the cottonwood.

Here is a link with some anatomy diagrams:
https://www.donqmedia.net/word-of-the-moment/plantigrade-digitigrade-and-ungulate/

and here is a link for everything you could possibly want to know about bird feet and legs!
https://en.wikipedia.org/wiki/Bird_feet_and_legs

Enjoy!

Pansie

  • Moderator
  • Newbie
  • *****
  • Posts: 9
Re: Bald Eagles Fact of the Day
« Reply #40 on: May 05, 2020, 09:30:46 AM »

On the Defense
During the first month of life, our eaglets either ignore an intruder or react to it as they would to the parent bird. Mark Stalmaster, author of The Bald Eagle, writes that they may even beg for food from a researcher who may climb into the nest.  However, this is soon replaced with a defensive mode. At five to six weeks of age, our nestlings will raise themselves up and call threats to any intruder who may dare come near the nest. At six to nine weeks of age the eaglets will become even more defensive, as they spread their wings, ruffle their feathers, open their beaks and hiss, and even display or strike with their talons. How fierce our eaglets can be!

An interesting note by Stalmaster states that an adult eagle may lay prostrate in the nest, feigning death, attempting to divert the attention of the intruder. The adult eagle may assume a stooped shoulder posture, wings held limp and heads bowed. Recall early on after hatching, the pecking that went on, the prone posture of the one pecked, the submissive behavior that puzzled some viewers.  Now we understand why, the instincts which play such a large part in their growth.


tulsaducati

  • Moderator
  • Jr. Member
  • *****
  • Posts: 80
  • Spread the Word: Lead-free hunting and fishing
Re: Bald Eagles Fact of the Day
« Reply #41 on: May 05, 2020, 05:24:54 PM »

Answering a couple of camera questions we've been seeing in chat:
The new view of the retention pond we have been seeing recently is provided to us by the new (replacement) camera that was recently installed atop the Visitor Center at the hatchery.  It looks across the retention pond back toward the N2B nest.  This camera also provides the view of Mom and DM2 when they perch on M2, the new maple tree location (the one that Mom moved to when the old maple had to come down).There is a certain amount of movement and vibration visible in this view from this camera; rather than the camera being attached to a sturdy tree trunk or limb like the other cams are, it is attached to a pole, and it just isn't possible to achieve the level of stability to prevent any movement. It doesn't take much movement to affect the view.
Please join us in our campaign to GET THE LEAD OUT. Together we can make the world a safer place for Bald Eagles and all wild life. We need you, THEY need you!
https://www.biologicaldiversity.org/campaigns/get_the_lead_out/index.html

eaglesrock29

  • Moderator
  • Hero Member
  • *****
  • Posts: 899
  • Hope is the thing with feathers ... Dickinson
Re: Bald Eagles Fact of the Day
« Reply #42 on: May 06, 2020, 08:36:49 AM »

Well, the eaglets are all 4 weeks old and counting.  Happy 4 Week Hatch Day, D36!   Week Five offers more wonderful developments to observe: 

At 5 weeks, they should measure approximately 24 inches from head to tail and weigh about 6 pounds!  When the eaglets are 5  to 6 weeks old, they can stand uprightly, may start to scream loudly, and attempt to tear up their own prey. 
 
The eaglets are beginning to preen regularly.  Preening removes dirt, smoothes their feathers, and distributes oil from the uropygial gland near the tail, which helps to keep the feathers healthy.    It may look itchy to some viewers but some some studies concluded that it is not.
 
Get ready! We will soon begin to see vigorous flapping, hopping, and moving about the nest!   

They will only need to be brooded in harsh weather.
« Last Edit: May 06, 2020, 08:50:06 AM by eaglesrock29 »
"When a storm is coming, all other birds seek shelter. The eagle alone avoids the storm by flying above it. So, in the storms of life may your heart be like an eagle's and soar above." - Anonymous

Iriscats

  • Moderator
  • Newbie
  • *****
  • Posts: 27
Re: Bald Eagles Fact of the Day
« Reply #43 on: May 06, 2020, 08:12:27 PM »

For May 7,2020

Feet and Toes

A bald eagles toes are part of its skeletal structure. An adult bald eagle's foot measures about 6 inches from front to
back excluding talons. Toes are numbered beginning with the back toe as digit 1, inner toe as digit 2, middle as digit 3,and the outer toe as digit 4. Each toe is made up of separate bones (singular=phalanges:plural=phalanx) Three of the toes point forward and the hallux points backward (in humans the hallux][ is the big toe) this toe arrangement is called anisodactyl.  The toes close securely much as human]s can clench our hands into fists.  Birds are called digitigrade because they actually walk on their toes and not on all of the foot bones (as humans do)
« Last Edit: May 07, 2020, 10:54:36 AM by Iriscats »

tulsaducati

  • Moderator
  • Jr. Member
  • *****
  • Posts: 80
  • Spread the Word: Lead-free hunting and fishing
Re: Bald Eagles Fact of the Day
« Reply #44 on: May 08, 2020, 07:40:32 AM »

How are feathers formed? Each new feather grows from a small outgrowth of skin called the papilla. As feathers mature, their tips get pushed away from the papilla, where the newest parts of the feather form. Like human hair, feathers are youngest at their base. The feather's structure develops as proteins are laid down around the surface of this bump of skin. It's here that the branching patterns form by smaller branches fusing at the base to make thicker ones' barbules fuse into barbs and barbs fuse into a rachis. As the feather grows, it stays curled in a tubular shape around the papilla until it is pushed away from the growth area. A protective sheath maintains the feather's cylindrical shape until it starts to disintegrate near the tip, allowing the mature part of the feather to unfurl. The sheath falls off and the feather growth process is complete.  From Cornell University's Academy.Allaboutbirds.com.  https://academy.allaboutbirds.org/feathers-article/2/
« Last Edit: May 08, 2020, 07:43:12 AM by tulsaducati »
Please join us in our campaign to GET THE LEAD OUT. Together we can make the world a safer place for Bald Eagles and all wild life. We need you, THEY need you!
https://www.biologicaldiversity.org/campaigns/get_the_lead_out/index.html