Rivers are a pair of narrow regions found on the upper-middle and the lower-middle side of the map. There are 2 rivers connecting the oceans. Each river has a current that pushes most animals and food in the directions of the current. Some animals, like Crocodile,Hippo, and Dragon aren't affected by the current. The 2 rivers have opposite currents; one goes from left to right, and the other right to left. You will evolve easily if you make a circle around the rivers, animals that climb hills and rocks have a advantage.They don't have sandy beaches, rather they have sharp sides. Food tends to spawn more in rivers, especially starfish. Also, food from both the land and ocean biomes can be found in the river. There's no point in going backwards, as it conflicts with the river's current.