Living about 15 to 20 years, Giraffes tend to darken as they get older.   In this close-up, you can really see how different their markings are.

They have a keen sense of smell, hearing and excellent sight.   Add the fact of their being the tallest land animal on earth and you have quite a sentry.   That's why it's not unusual to find other non-agressive animals in the vicinity of Giraffes; they are taking advantage of the Giraffe Early Warning System.   and, even though they can weigh two tons, when they need to, they can reach speeds of 30 miles and hour.