The _ is the tallest modern land animal. It can be over 5. 5 meters tall. Its neck alone may be 1. 9 meters long. Yet the giraffe has only seven bones in its neck, the same number as in the humans'. Even a small bird has many more bones in its neck than a tall giraffe. Each bone in a giraffe's neck is very long, while the bones in a human's neck are short. That makes the difference. A female giraffe gives birth to one baby at a time. The baby, called a calf, is about 1. 9 meters tall at birth. By the age of eight it is full-grown. The giraffe eats mostly leaves. Because it has a long neck, it can reach the high leaves on the trees. ,. The bones in a bird's neck are   _  .
as big as in a human's neck as big as in a giraffe's neck many more than in a human's neck much smaller than in a giraffe's neck