What was the most important part of the Southern
strategy?

To defend its land until the North gave up

Nobody:

Me: Hah I did it already (OwO)

1. Over-hunting
2. A disappearance of a primary food source
3. Drought
4. A more competitive species taking food
5. Different environment conditions that is difficult for the species to survive
6. Something killing off a certain gender of a species
Hope it helps! :)