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.
But they do it very rarely. A giraf has a lot of legs and neck to coordinate when he gets up, By that time the hyenas or lions already got it. So keep yourselve in a start position, it saves your life. Just like horses giraffes can lock their legs and sleep standing u whitout faling down.