What is the difference between a bird and a fly?
553787
a bird can fly but a fly can't bird.
183391
Grasshoppers and all insects have trachea, that is, tubes formed by invagination that extend inside their bodies and carry oxygen directly to the tissues. It's a very efficient system, but doesn't work at large sizes.\n\nBirds have lungs and air sacs. Contrary to the mammalian system, the flow of air in birds lungs is continuous, and the capillaries are arranged at right angles to the airways. It's also very efficient. \nBut other than in their high efficiency, I don't see the similarities.
3269
an African or European swallow?
1042915
It depends on the species of bird. Some it may take months, some weeks, some a week, and others just a few days. It also depends on the health of the parents and baby. If the parents are healthier they can take better care of the baby so it will be healthier and can fly sooner. Also a healthier parent will teach the baby sooner and quicker. But some bird such as the ostrich, emu, and South American rhea do not fly. Sorry I was unable to be more specfic as it would have been impossible to give you an exact time period. After originally answering this question you e-mailed me saying that the birds were sparrows. Sparrows are small birds and as such, will learn to fly quickly. It may be anywhere around 6-14 days.
975004
A birds bones are lighter and hollowed out.  The feathers are lighter then human hair.  There bodies are streamlined similar to an airplane.  Depending on what kind of bird,  these adaptations may vary.  An ostrich is much heaviar then a falcon.  A falcon is much like a fighter jet, it is built for flight and speed.  They achieve high speeds by having thin wings and light bones,  many birds are built in this way and some may not fit the category.  Some are not built for flight.  But these adaptations are set to make different birds greatly adaptable to there surroundings.
572291
From Wikipedia\n\n"Apart from its greater size, the Raven differs from its cousins the crows by having a larger and heavier beak, and a deeper and more varied barking prrrukk call note. Other field points are the shaggy throat feathers and a longer, wedge-shaped tail"
555808
flies can set in motion the wings 200 times/sec....\nso,flies can fly very-very fast, that is 300mil/hour or 50 kilometres/hour
859989
They are both modified forelimbs. However both are modified in very different ways, as they evolved independantly. Whereas bats rely on a flap of skin stretched between fingers, birds have feathers that attached at various places to produce lift/ direct airflow.
593379
what is the difference between the two
1087265
About one fly height.
557776
a fly flies as high\nas a fly can fly\nand if i were a fly\nso high would i fly\nthat my wings touch the sky\n(at least I would try)\nand so with a sigh\nI now say goodbye ~
1031888
Flys don't move with the lift.  If the fly is in the air when the lift starts moving up, the fly must also move up -- or it will end up on the floor.  If the fly is perched somewhere on the lift wall, then it will gain momentum with the lift.  If the fly releases itself from the wall, it first has no problems because it is traveling at the same momentum as the lift, but it immediately starts to lose the momentum and must again fly in the same direction as the lift.\n\nTHE FLY IS NOT HELD IN PLACE BY THE AIR IN THE LIFT.
681664
the difference between a chicken and a baby is that\na chicken is a result of a sitting hen\nwhile a baby is the result of a standing cock
241563
Bats are mammals and they do fly like birds.Squirrels can only glide a limited distance.
717949
They are "cold blooded."  Unlike warm blooded mammals like humans, flies and other insects do not produce their own heat.   They need to get heat from outside sources, like the sun or the air.  When it's cold, they move slower because their whole physiology has slowed down.
1103147
Bee= Male (the stinger)\n"gets friendly" with\nBird= Female
268841
ok\n Hoatzin chicks have archyopterix-style claws on their wings\n\nPuffin`s beaks are not as colourful out of the breeding season\n\nThe Goatsucker (no, not el Chuppacabra, the bird!) of the USA is called a Nightjar in the UK\n\nAmerican Robins are not related to european Robins, they are in fact a type of thrush\n\ncormorants have to open their wings to "dry" them as they`re not as waterproof as other waterbirds.