| Birds are warm-blooded, bipedal egg-laying | | | | crepuscular which means that they are active |
| vertebrates that are characterized primarily by | | | | during the night. Several birds will migrate long |
| their physical features of feathers, forelimbs | | | | distances to take advantage of optimal habitats. |
| modified as wings, and hollow bones. Birds range | | | | With that aside there are others that will spend |
| largley in size from tiny hummingbirds all the way | | | | almost all their time at sea. Some birds have the |
| up to the huge Ostrich. Depending on how you | | | | ability to stay up in the air for days at a time, |
| look at it, and what your viewpoints are there are | | | | even sleeping while in the air. |
| approximately ten thousand different species of | | | | All birds have similar characterists: |
| living birds. Note the living. there are several | | | | - Bony beak with no teeth |
| others that have become extinct throughout | | | | - Laying of hard-shelled eggs for reproduction |
| human history. This mass in numbers makes birds | | | | - high metabolic rate |
| the most diverse class of terrestrial vertebrates. | | | | - Light and strong skeleton |
| Birds are at the majority of times a very | | | | Most birds also share the common trait of flight |
| differentiated class, with some feeding on nectar, | | | | however there are sevaral species of flightless |
| plants, seeds, insects, rodents, fish, carrion, or | | | | birds, that exist mostly on islands. These are birds |
| other birds. Most birds are diurnal, which means | | | | that once used to have the ability, but do to |
| that they are active during the day. Some wild | | | | adaption have lsost it. A famous flightless bird is |
| birds, such as owls and nightjars, are nocturnal or | | | | the kiwi which exists in New Zealand. |