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May 17 12 6:28 PM
May 17 12 6:29 PM
Rickson1979 wrote:Its a fictional book you muppet.
May 17 12 6:47 PM
Vodmeister wrote:We can discuss that somewhere else. This is Polar bear vs Kodiak bear.
Mar 12 13 6:59 AM
Mar 12 13 7:01 AM
Mar 15 13 9:24 AM
Apr 2 13 12:04 AM
Well Dr Larry Van Daele stated that the Kodiak bear is the largest bear in the world.
Apr 2 13 2:17 AM
Apr 16 13 8:44 AM
BrotherBear wrote:The polar bear is the worlds biggest bear on average. He is taller and longer due to his elongated neck and body which are modifications for swimming. He is heavier due to more fat which is needed in his arctic environment. In a fight, a typical alpha male Kodiak bear would most often defeat the typical alpha male polar bear. He has a more massive head and stronger jaws. He has a shorter and more robust neck as well as more massively muscled shoulders.
Apr 17 13 7:52 AM
Vodmeister wrote:Polar Bear.
Because Brown Bears have never reached above 1700 lbs, even in captivity. Polar Bears reach 2200 lbs in the wild.
Apr 17 13 7:53 AM
Apr 17 13 2:31 PM
BrotherBear wrote:Regarding Bone Density: Are you still blabbing about bone density? So now the polar bear has adamantium coated bones I suppose? I read once where a big tom cat that enjoyed killing birds attacked a hawk which had a broken wing in a sling. That bird ( which has thin hollow bones ) tore up the cat ( which has some fairly dense bones ). In other words - stupid argument.
Apr 18 13 6:03 AM
Apr 18 13 7:30 AM
Apr 18 13 12:45 PM
BrotherBear wrote:The kids says: And you are stupid for believing that mammals actually have stronger bones than birds, because they don't. *Birds have thin hollow bones designed for flight. I have eaten chicken, turkey, duck, goose, quail, dove, and even a sea gull once. I can easily snap a birds bone in my hands. I challenge anyone here to compare the strength of a bird bone with that of a pig or a cow.
Apr 18 13 2:39 PM
Dumont measured the density of the cranium, the upper arm bone or humerus and the thigh or femur bones in song birds, rodents and bats by measuring bone mass and volume. "I found that, on average, these bones are densest in birds, followed closely by bats. Many other studies have shown that as bone density increases, so do bone stiffness and strength. Maximizing stiffness and strength relative to weight are optimization strategies that are used in the design of strong and stiff but lightweight man-made airframes," she points out. Density is a measure of mass per unit of volume; dense bones are both heavier and stronger, much as a titanium toothpick would be stronger than a wooden one.
Over time bird bones have evolved specializations that maximize stiffness and strength, Dumont says. These specializations include high bone density, a reduction in the total number of bones, fusion of some bones, and changes in bone shape. For example, a long history of studies have shown that the main bone in the bird wing, the humerus, is quite round in cross-section. This makes it stiffer in the same way that a round toothpick is harder to snap than a flat one.
Galileo described bird bones as lightweight in 1683, Dumont says. Her new data help to dispel the common misconception that bird skeletons are lightweight relative to body mass. Instead, bird and bat skeletons only appear to be slender and delicate -- because they are dense, they are also heavy. Being dense, strong and stiff is one more way that birds' and bats' bones are specialized for flight.
*Bird bones are greater in density than those of an equal sized mammal, but thin and hollow never-the-less. This means that the bones of a bird are denser than those of a mammal of size parity, yet no stronger.
Apr 18 13 2:42 PM
Apr 18 13 6:22 PM
The skeletons of birds are
universally described as lightweight as a result of selection for minimizing
the energy required for flight. From a functional perspective, the weight
(mass) of an animal relative to its lift-generating surfaces is a key determinant
of the metabolic cost of flight. The evolution of birds has been characterized
by many weight-saving adaptations that are reflected in bone shape, many of
which strengthen and stiffen the skeleton. Although largely unstudied in birds,
the material properties of bone tissue can also contribute to bone strength and
stiffness. In this study, I calculated the density of the cranium, humerus and
femur in passerine birds, rodents and bats by measuring bone mass and volume
using helium displacement. I found that, on average, these bones are densest in
birds, followed closely by bats. As bone density increases, so do bone
stiffness and strength. Both of these optimization criteria are used in the
design of strong and stiff, but lightweight, manmade airframes. By analogy,
increased bone density in birds and bats may reflect adaptations for maximizing
bone strength and stiffness while minimizing bone mass and volume. These data
suggest that both bone shape and the material properties of bone tissue have
played important roles in the evolution of flight. They also reconcile the
conundrum of how bird skeletons can appear to be thin and delicate, yet
contribute just as much to total body mass as do the skeletons of terrestrial
bones are strong in proportion to their weight, and many are hollow, reinforced
with an internal crisscrossing strut system that provides stability. In
addition to the obvious advantage of reducing weight, hollow bones are
pneumatic, which means that the hollow air spaces within the bones are directly
connected to the respiratory system, enhancing respiratory efficiency. Flight
may have had some influence on bird skeletons, but it is not solely responsible
for its design. A species of carnivorous dinosaur (Aerosteon riocoloradensis) with telltale
characteristics was recently discovered: it sports hollow pneumatic bones like
those of birds, suggesting that the system may have evolved simply for more
efficient breathing, to reduce weight, or to help keep the animal cool. While
bird bones tend to be lightweight, individual bones are not always lighter than
the bones of other vertebrates of similar proportions. Nonetheless, the skeletal
structure as a whole is light and strong. The quintessential case is the
frigatebird, whose entire skeleton is only half the weight of its feathers.
pelvis, and thoracic region of the spine are all fused to create sturdy
platforms that reduce weight and provide the rigidity necessary to maintain
posture of the body during flight. The ribs also have lateral extensions that
overlap (called the uncinate process), bracing together to form a sturdy cage
that protects the lungs and heart from the crushing force of beating wings.
This interlocking rib feature, which until recently was thought to be a
characteristic specific to birds, has also been discovered in nonavian
dinosaurs (Zhou 2004).
structure of a bird’s neck makes it quite flexible. Because the forelimbs have
little use beyond flight or swimming, the neck is crucial for the task of
preening: the head must be able to reach most of its body to properly tend to
feathers. While mammals have seven neck vertebrae, birds have eleven to twenty-five.
furcula, the fused clavicles that we are familiar with as the “wishbone,” is
much like a flexible spring that aids flight: on the downbeat, muscles contract
and squeeze the ends of the furcula toward each other. When the wings have
reached the lowest point of the downbeat and begin to draw upward, the furcula
“releases” and rebounds to its original position, much like a bow letting loose
provide sturdy support for the flight feathers, the bones of the “hand” are
reduced and fused. The bone of the forearm, the ulna, has a series of bumps
along its trailing edge to which the secondary flight feathers attach directly.
The keel, or breastbone, is extremely pronounced in most birds. Large and
bladelike, it is a thin slab of bone along which the massive flight muscles are
anchored. It also provides additional protection for the heart and lungs. Some
flightless birds, specifically the ratites, have no use for a pronounced keel,
and it is therefore absent. Others, such as penguins, use their “flight”
muscles for swimming underwater, so they have retained their pronounced keel
and powerful muscles.
is extremely light as well. The heavy jaws and teeth of pro-avis were
eventually replaced with a lightweight bill covered in a horny sheath. The
teeth and jaws were replaced by the gizzard, a muscular organ that pulverizes food.
Set low and far back in the body, it enables birds to essentially “chew” with a
mechanism that does not hamper flight but makes it more efficient. Like its
skeleton, a bird’s musculature is well adapted for flight. The muscles of most
striking size are those of the breast, which power the wings. In many birds,
these bulky muscles make up a full third of its overall body weight. And in
species such as grouse, which make powerful bursts through the brush, they may
contribute nearly forty percent.
most part, musculature is centered on the underside of the bird, establishing a
steady center of balance. In comparison, the back has little muscle mass but
stabilizes the hard-working underside. The wings and neck are covered with a
complex, lightweight network of muscles that provides optimum strength and
has had its effect on the heart as well: this organ is the ultimate in
endurance capability. Like mammals, birds have hearts with four chambers;
however, they are often proportionately larger. A sparrow’s heart is three
times larger than that of a mammal of the same size. Bird hearts are also
stronger and pump faster than those of mammals: the fastest rate belongs to the
hummingbird, at one thousand beats per minute. Smaller birds have proportionately
larger hearts than larger birds, and birds that migrate have proportionately
larger hearts than nonmigratory species.
Apr 18 13 6:26 PM
BrotherBear wrote:*Birds have thin hollow bones designed for flight. I have eaten chicken, turkey, duck, goose, quail, dove, and even a sea gull once. I can easily snap a birds bone in my hands. I challenge anyone here to compare the strength of a bird bone with that of a pig or a cow.
Florida Driver Hits Owl That Survives Miles in SUV
The owl that a Florida tourist hit with her SUV and unwittingly transported for about 100 miles in the grill of her vehicle appears to have survived the ordeal none the worse for the ride, although vets said today they are treating the anemic bird with antibiotics out of caution.
Sonji Coney Williams made the startling discovery last week when she reached her destination in South Florida. Staring at her from beneath the hood of her SUV were the two large golden eyes of a live owl, lodged in the car’s grill.
Williams was reportedly headed south on the Florida Turnpike Feb. 7 when the owl collided with her vehicle near Yeehaw Junction in Central Florida. Williams was bound for Plantation, Fla., to visit her son. While going about 60 mph, she assumed the bird she had hit died on impact.
“He never moved, and so I said, ‘Oh, my God, I hit a bird.’ And I felt so bad,” Williams told The Associated Press. “But it was very dark, and we didn’t pull over.”
The next afternoon, while running errands, Williams discovered the live owl trapped in her car.
A family had pulled in front of her parking space and flagged her down, calling attention to something caught in the grill of her vehicle.
“‘Yes, what is it?’ And they said, ‘It’s an owl.’ And I said, ‘An owl?’” Williams told the AP.
Williams then discovered the bird she had hit the night before still alive and blinking from the small space between the grate and hood of her SUV. It was a great horned owl, a breed common to Central Florida. It can grow to 2-feet tall.
Astonished to find the creature wedged in her truck for nearly 24 hours, Williams told ABC affiliate WFTV, “I’m about to faint. I’ve never experienced anything like this before in my life.”
After encountering the trapped owl, Williams called the Florida Fish and Wildlife Conservation Commission. Agency officials managed to extricate the owl, which seemed to be in good health, an agency representative told ABC News today. They eventually moved the owl to the South Florida Wildlife Center in Ft. Lauderdale, which said today it has run the owl though a battery of tests and hopes to return it to its Central Florida natural habitat after its appetite is restored and it gets a clean bill of health.
It’s unclear whether the bird is male or female.
As for driver Williams, she found it difficult to look at the finally freed owl, even shedding tears over the animal’s predicament.
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