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.
When giraffes walk, they move both legs on one side of their body and then both legs on the other side; this is unique to giraffes. However, they run in a similar style to other mammals, swinging their rear legs and front legs in unison. They can reach 55 km/h (35 mph) at full speed but only in brief spurts.
Male giraffes spend about 22% of the 24 hours walking, compared to 13% for female giraffes. The rest of the time male giraffes are searching for a female giraffe to mate with. Giraffe herds do not have a leader and individual giraffes show no particular preferences for others in the herd.