"The Great Wildebeest Migration is really about the search of over 2 million ungulates for rain, and with it, greener pastures. This herd had finally arrived at the lush woodlands of Ndutu, their canter kicking up a dust cloud that formed a dramatic blue curtain at dusk. The reality for them is that the grass will always be greener somewhere else, and they will never stop this endless journey right till their very last breaths." This stunning picture was sent to us by Instagram user @hengyirui.