First time we entered the Serengeti national park, we saw that the Wildebeest were starting their congregation at the southern tip of the park. Their herd sizes were small as it was the beginning of the congregation and most of the Wildebeest were still shy. They would run away from the sides of the road as soon as they saw an approaching vehicle. You can see more of that experience in this earlier post.
This time we were on our return journey and were exiting Serengeti national park going towards the Ngorongoro Crater. We noticed that the congregation had swelled in size. The Wildebeest herds could be seen all over southern Serengeti. More importantly the Wildebeest seemed to have become more tolerant of the passing vehicles and no longer scooted away at the sight of every vehicle. The road sides were now lined with Wildebeest and you could stop, look and choose the ideal subjects for photography and even wait for for a couple of minutes for a nice pose.