Answer is Retrograde motion
Most of the time planet moves in expected path near the ecliptic which is east to west. Some times each planet turns around and moves to the east for a period of time, then it turns around to head in west direction again making a loop or zig-zag against the star background. This is called retrograde motion. Thus retrograde motion is the change of direction of the planets in loop.
I think it might be warm water
The Everglades located in Florida is an example of a freshwater wetland
A supercell is a thunderstorm with a deep, persistently rotating updraft. Supercells are the least common form of thunderstorm yet they are potentially the most violent. Large hail of greater than baseball size, strong damaging winds, and tornadoes can accompany these storms
Hope this helped
The sahara made migrating rough because it was a desert but it was easier to pass through rather than south afria going through jungles