Population ecology is the study of these and other questions about what factors affect population and how and why a population changes over time. Population ecology has its deepest historic roots, and its richest development, in the study of population growth, regulation, and dynamics, or demography.
While running, the neck of a giraffe moves backward and forward to keep the animal balanced. Giraffes have a top speed of about 56 kilometres per hour (35 miles per hour), however, because its legs are so long a galloping giraffe does not appear to be going very fast.
Giraffes are non-territorial, social animals. They travel in large herds that are not organized in any way. Herds may consist of any combination of sexes or ages. Giraffes have small horns or knobs on top of their heads that grow to be about five inches long. These knobs are used to protect the head in fights.