Rebuilding Role Play (Animals + Natural Disaster)

Introduction

Skyscrapers have been reduced to rubble in a recent earthquake. Tsunamis soon followed, flooding all of North America. Some animals fled to the mountaintops, while the others got washed away. The sea level hasn't yet reached the mountaintops, so those animals who fled are still safe. For now.
There is no contact with the rest of the world. There are no humans in sight. There is only the remnants of buildings floating on the surface of the water that could carry animals from mountaintop to mountaintop.
Our story takes place on the southern end of the Rocky Mountains. Your job is to make sure your species doesn't die out.