What are the most reasons that birds can fly?
343725
to get food and water
887471
they can!!!!!! just short distances.   ever try to catch one:) it will fly!!!!
750988
How does the bird's vertebra indicate that it evolved to support flying? (Answer: The thoracic vertebrae are fused to provide a rigid upper shell to withstand the muscular forces of flight muscles. As partial compensation for this rigidity, birds have more neck vertebrae than many animals to provide enough flexibility to feed, groom, etc. See ref.)
726758
Birds fly in V formation to reduce total drag on the flock.  By flying closely behind each other, they are able to draft off of one another and cut down wind resistance compared to flying in a random pattern.  The lead or point of the V is alternated when the lead bird (who does not benefit from drafting) settles back to the rear of the formation and another bird takes it's place.
6433
The legs of a fly have a primary role of helping the fly to land and lift off, and also move about a little when its not flying. If the fly would not have wings, it would be able to move futher on its legs, but the mobility would be severly restricted because the legs haven't been used in that sense before. This fact is confirmed from experimentation done in around 2003, where a genetically mutated fly which didn't grow any wings tried to move solely on its legs.
241563
Bats are mammals and they do fly like birds.Squirrels can only glide a limited distance.
43957
birds can be found all over the world. It all depends on what kind of bird.
776602
i watched a tv program on this about birds that swarm and its all to do with a few factors ie all the birds are equal distance apart for flying purposes . no bird wants to be on the outside of the swarm or flock due to predator that target such swarms "falcons". so if you can visualise a bird has to have a zone around it to fly and it don't want to be on the edge.when the bird  near it moves to the centre of the swarm to stop being on the edge.the new bird that's exposed whether it be from the side above or below that bird will then move to gain cover in the swarm.hence the shapes you get and the sudden change in direction of the swarm you see in the sky.there is a a computer graphic program that runs this formula but i don't were to tell you to go for this.
284184
Geese fly in a "V" formation for air resistance and to enable the other geese to follow in the "drag" created by the geese in front of a particular goose except the one in the lead. There is turbulence in the air currents made by each goose.\nThe lead goose encounters the most air resistance. They trade off leaders on occasion.\nThe reason one side of the formation is longer than the other is that there is usually an odd number of geese in the formation or that the air resistance and turbulence is less on one side or the other.
706631
That is quite a difficult question to answer as you would have to know how many calories are in a particular food item (which can be determined using a calometry bomb) and how many calories are expended during flight. I would say that no, a pigeon would need more than a few grams of seed to fly kilometers (it also depends on how many kilometers were taking, 2 vs 100 is a huge difference). Many birds migrate overlong distances, but make stops to refuel and take adventage of flight formation (the V of geeese), wind currents, updrafts and anything else they can to make it easier so they really arent technically flying the entire distance, they glide a great majority of it. Although, knowing that they are going to be going a long way, birds do eat and store quite a bit to fuel them. \nWings and the tail provide steering, but its primarily the wings. \nSo, no a single meal is not enough, but yes the do consume enough calories to fly great distances.
884128
Yes indeed, I agree with you that it would be easier for them to chew worms if they have teeth. However teeth are heavy and would make it very difficult for birds to fly.  This is especially important for birds of prey who must fly swiftly to catch their food. Due to this "anatomical structural design"  birds have light  beak which is good for giving food a good mashing. Birds "chew" their food inside a part of the stomach called the gizzard.  The gizzard has strong muscles which grind the food against a rough inner surface to break it down.♥
925479
FLY like a BIRD!!!\nbecause swimming like a fish has restrictions... if there's no water.. you cant swim anymore... unlike flying... you will have unlimited access over things and creatures!!!!
406248
Hummingbirds can fly right, left, up, down, backwards, even upside down due to their special wings. Hummingbirds are also able to hover by flapping their wings in a figure - 8 pattern.   http://www.kidsplanet.org/factsheets/hummingbirds.html
461940
Yes. They could fly inside a space shuttle. Birds would have a hard time adjusting to the lack of gravity though, and would look funny trying to fly. Assuming there would be the normal amount of air inside the shuttle, the wings would be effective as they would push some air around.
1067132
There are several advantages to flying at night instead of during the day, some or all of these may have an influence on migration times.\n\nTaking their direction from the position and polarized light of the setting sun ensures that they start off facing the right way.\n\nDaytime predators such as falcons are avoided.\n\nDehydration that could result from flying for hours in warm, sunlit skies is reduced.\n\nThermals and updrafts are less common at night, without sunlight creating pockets of differential heating.  This makes night flying smoother, and more stable.\n\nFlying at night means that foraging activities take place on the ground during the day when most birds visual acuity is greater.  This means that food detection and selection as well as predator avoidance are scheduled at a time when their senses are best suited for the task.\n\nAt night the moon and stars are often visible, adding back-up navigational aids to the internal compasses and directional sense that the birds already have.
594900
Generally, as with most animals, they can sense weather patterns and climate changes.  When something is out of the everyday pattern, their behavior changes.  As far as hurricanes: you usually see the birds leave waayyy before most of the people do.\n\nSo yeah, they fly away before it even hits land.
679764
My pet Emu -Larry- says you are mistaken. In reality birds do not fly. See, you were outside, enjoying a lovely day when you stumbled upon a group of kids playing in the park. What you saw was nothing more than a fowl ball.