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Author Topic: Bald Eagles Fact of the Day  (Read 18013 times)

Pansie

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Re: Bald Eagles Fact of the Day
« Reply #60 on: May 22, 2020, 09:32:15 AM »

Foraging
Eagles have numerous methods of foraging for food. As we know they are considered 'opportunistic' eaters. Of course the easier the better, and they have no qualms about stealing from another source. Are they often considered 'lazy', yes, but we need to realize that when the opportunity becomes challenging, they will rise to the occasion. They can be quite serious about their meals.

According to Mark Stalmaster, author of 'The Bald Eagle', early evolutionary adaptation may have been genetically passed on through generations. Perhaps food was scarce in the early times, and the Eagle became adept to stealing from others in order to survive. (This may also be where imprinted behavior plays a part as the parent raises their brood.)

The NOVA special, Eagle Power, showed us a bit of the different methods of foraging.  We saw 'aerial chases', where they attacked and caught their prey in the air. There is the 'running or walking' attack, where they will pounce on opponents and battle fiercely with their talons or wings, always being careful to protect their eyes.

There is also the 'mock attack' where an Eagle will show force, then back off a bit, testing the will and strength of the opponent. Smart raptor!

As we watch these eaglets,  we may view 'beaking', jabbing or striking at another to drive it away. They may scream at the competition. Fluff their feathers and thrust their wings forward.  The 'beaking' Eagle will hold it's head and body lower over the food source, reducing the chances of attack. Also 'mantling',(which we have often seen), in which they will cover the food with their body and outstretched wings.

All methods are ways in which the Eagles shall find the food they need to sustain their offspring and themselves.





jfrancl

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Re: Bald Eagles Fact of the Day
« Reply #61 on: May 23, 2020, 12:36:42 PM »

Imprinting is defined as a genetically programmed learning mechanism formed during a brief receptive period. This usually occurs soon after hatching and generally establishes a strong long lasting behavioral response to an object or a specific individual, such as parents or siblings.

Environmental imprinting starts on the nest and immediate surroundings. After fledge they imprint on a larger area which may include rocks, cliffs, man made structures and so on.

Habitat and geographical imprinting or environmental imprinting, are important to birds that disperse a great distance and are migratory, then those who are more sedentary,  as they will need to hone their abilities as to what habitat and nesting area is important to look for as adults.  Studies have shown that there are strong parallels between the type of nest in which a young eaglet has been reared and the type of nest they will choose or build as adults. 1st time breeding birds will look for a similar habitat in which it was raised, often a short distance from their natal nest area.
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

Bob1603

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Re: Bald Eagles Fact of the Day
« Reply #62 on: May 23, 2020, 03:32:22 PM »

We often hear the eagles vocalizing and it is interesting to note they are able to do that without any vocal cords.  They have bones in their throat and their hi-pitched, shrilling, squeaking, and screeching sounds are made by passing air over those bones.  All of this is done in an area of the throat called the syrinx that is located at the posterior end of their trachea where the windpipe is separated going into the lungs.  The syrinx is similar to the larynx of mammals.  Syrinx is derived from a Greek word for pan pipes. 

Iriscats

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Re: Bald Eagles Fact of the Day
« Reply #63 on: May 24, 2020, 09:22:29 AM »

May 24, 2020

D34 and D35 are 49 days old today.  They have reached 7 weeks. D36 is 46 days old, and here is what we can expect.

The ability to self-feed is evident at about the 6th to 7th week although, it will be a long time before the young birds become proficient.  They are almost as large as their parents.  By 7 weeks of age, young eagles have attained almost their full fledge weight and very much look ready to fly, but the tail feathers have only started to lengthen and their wing feathers are well below fledging length.

« Last Edit: May 24, 2020, 09:26:09 AM by Iriscats »

Faith

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Re: Bald Eagles Fact of the Day
« Reply #64 on: May 25, 2020, 03:40:23 PM »

We are often asked how we will know if the eaglets are male or female.  The truth is we will likely never know.  The only way to be 100% accurate in determining the gender of an eagle or eaglet is by doing a DNA or blood test.

Another method often used is the Bortolotti Rule, which uses measurements of the bill depth and hallux length in a formula to determine gender.  The formula is (Bill depth X 0.392) + (hallux length X 0.340) - 27.694, in centimeters.  A positive result = female.  A negative result = male.  This method is about 90% accurate.
« Last Edit: May 25, 2020, 03:42:07 PM by Faith »

pyrmum1

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Re: Bald Eagles Fact of the Day
« Reply #65 on: May 26, 2020, 08:16:22 AM »

Metabolism is defined as a set of chemical reactions occurring in cells of living organisms to sustain life.  These chemical reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments.  Flying requires a higher body temperature & a faster metabolic rate. Smaller birds have a faster metabolic rate than larger birds, i.e. raptors. Researcher, Nick Fox, states there are 3 types of raptor metabolism:

1) basal metabolism,  the energy needed to keep basic bodily functions operating and to keep the heart beating

2) existence metabolism, the extra energy a raptor needs to cope with effects of temperature and climactic changes on its body, such as wind and rain

3) productive metabolism, energy needed for activities such as hunting, courtship,
« Last Edit: May 26, 2020, 08:18:41 AM by pyrmum1 »

oregonian1944

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Re: Bald Eagles Fact of the Day
« Reply #66 on: May 27, 2020, 08:30:14 AM »

Many have asked what happens after the eaglets fledge.  Will we still see them?

After they have fledged (left the nest), they will be in advanced eagle training from their parents.  That includes honing their flying skills, landing techniques, soaring with their parents, learning to hunt for prey and fishing.  At the same time they will continue to depend on their parents for food, often returning to the nest to eat.  Learning to hunt takes time and many misses, so often they will scavenge on carrion.  They will remain close to the nest for a few weeks, but eventually will venture further away and explore other areas. It is thought that by the age of 16 weeks or so, they are pretty self-sufficient and by their 20th week may leave the parents' home range in Sept. or early October.

pyrmum1

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Re: Bald Eagles Fact of the Day
« Reply #67 on: May 28, 2020, 09:14:06 AM »

MEMORY:  The raptor memory is typically very good and aids them in their migration.  Like we humans, the raptors' comprehension and ability to remember is better for sights than for sounds. The raptors' sharpness of vision and ability to recognize things surpasses that of we humans.

Nick Fox, researcher, had a trained goshawk. She would sit quietly on her perch outside in the yard. As soon as she saw a portion of Fox's head appear in the window, she would call to him immediately.   Observations on memory noted are related mainly to trained raptors.  Fox states a trained hawk will recognize its owner after more than a year of separation. It will also recognize and remember the meaning of the lure used as bait as well as the hood the trainers use.
« Last Edit: May 29, 2020, 08:18:36 AM by pyrmum1 »

pyrmum1

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Re: Bald Eagles Fact of the Day
« Reply #68 on: May 29, 2020, 08:48:18 AM »

MEMORY CONTINUED:  Fox (researcher) states raptors have a good memory and forget very little.  The capacity for each bird to store information in its memory is an individual event.  As with humans, their comprehension and recollection is far superior for sights than it is for sounds. As predators, their visual acuity and recognition exceeds ours.  Fox further states that hawks recognize places where they have caught prey in the past and will sometimes revisit that area in order to check out the place.  However, with so much land being developed, raptors are finding that what they remember as good places to hunt, are changed & more difficult to recognize.  Fox points out that memory should not be confused with intelligence.
« Last Edit: May 29, 2020, 08:58:02 AM by pyrmum1 »

Bob1603

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Re: Bald Eagles Fact of the Day
« Reply #69 on: May 29, 2020, 10:01:51 PM »

We all have heard about the comeback of the American Bald Eagle and here is true story that speaks to that.  It's a fact that the bald eagle is thriving more then ever!

https://www.cnn.com/2020/05/28/us/bald-eagles-massachusetts-scn-trnd/index.html

glogdog

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Re: Bald Eagles Fact of the Day
« Reply #70 on: May 30, 2020, 06:18:05 AM »

An adult bald eagle flies (cruising speed) at approximately 30-35 miles per hour and can dive at a speed of up to 100 miles per hour.  Measured flight speeds of migrating eagles were recorded at between 36-44 mph (Broun and Goodwin 1943).  In flight, they can reach an altitude of some 10,000 feet.
glogdog

tulsaducati

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Re: Bald Eagles Fact of the Day
« Reply #71 on: May 30, 2020, 06:14:55 PM »

For May 31, 2020:
At about 8 weeks, eaglets are well feathered and have reached more than 90% of their mature weight. They grow so quickly that a standing eaglet may droop its wings, since the developing wing feathers are blood filled, and their wings can be heavy. Eaglets may practice hovering (sustaining air briefly above the nest) and those all-important landings. Wing flapping and hovering strengthens their pectoral muscles for flying. At this stage, they can be called nestlings, eaglets, and juveniles. Beaks are blue-black, eyes are dark brown, they are more aware of their surroundings, and may react to birds as well as humans nearing the nest.
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

Pansie

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Re: Bald Eagles Fact of the Day
« Reply #72 on: May 31, 2020, 04:58:13 PM »

FOD for June 1, 2020
Eagle Feathers
According to the U.S. Fish and Wildlife, no one other than Native Americans and Alaskan Natives may possess any part of an eagle. Their use of eagle feathers is for religious and cultural purposes. Only a federally recognized tribe may obtain a permit for feathers. The sale to outside entities is prohibited.

According to these cultures, the feather is a powerful symbol that represents honor, trust, wisdom, strength, power and freedom. When a feather falls to earth, it is believed to carry all of the bird's energy, and is a gift from the sky, sea and trees.

While hawk and pheasant feathers may also be used, the eagle feather is held in highest esteem, for the eagle is thought to be the bravest and strongest of all birds. Native American warriors who showed great bravery during battles were gifted with eagle feathers, a symbol of strong medicine representing the highest, bravest and holiest of all feathers.

Eagle feathers are used to adorn the sacred pipe during ceremonies, and if dropped on the ground, a special ceremony is held asking for permission to pick it up, never to be dropped again. To wave an eagle feather over a person's head or a group, signifies blessings, happiness, prosperity and peace.

blog.nativehope. org


« Last Edit: June 01, 2020, 12:38:05 PM by Pansie »

Iriscats

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Re: Bald Eagles Fact of the Day
« Reply #73 on: June 01, 2020, 08:04:18 PM »

FOD for June 2, 2020

Bergmann's Rule: Applies to many warm-blooded birds and other animals that live in widely
different environments. Large bodies are at an advantage because they lose heat at a slower rate.
Northern bald eagles are so much larger than their southern counterparts that their males are
larger than southern females. In states that are mid-latitude-- and where these 2 subspecies meet
it is very hard to tell the difference between northern and southern varieties because the size
difference is minimal. The smallest known specimens are those from Florida, where an adult
male rarely exceeds 5.1 lbs. The largest are the Alaskan eagles, where a female may exceed 17
lbs and have a wingspan of over 7.9 feet.
« Last Edit: June 01, 2020, 08:11:06 PM by Iriscats »

smileawhile

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Re: Bald Eagles Fact of the Day
« Reply #74 on: June 02, 2020, 09:20:06 PM »

FOD for June 3, 2020

More about developing feathers and fledge:
   It can take up to five weeks after fledge for the flight feathers to be fully grown. Once the wings are completely formed it can still take a week for the blood to retract from the feather shafts, at which time the shafts become firmly attached to the bone.  This is referred to as hard-penned. Until this happens the feathers are more susceptible to damage and can't withstand much vigorous flight.
   So at fledge the eaglets flight feathers are blood-filled (therefore a little heavy) and longer than adult feathers, making for interesting and challenging flight lessons. Take-off is fairly easy but landing demands accuracy and skill. Practice practice practice!

Reference: Dr. Scott Nielsen  A Season with Eagles

https://www.youtube.com/watch?v=DpilgeM5lUk
https://www.youtube.com/watch?v=g56Z4z3v35U