Earth 's magnetic patterns are used for finding locations by animals that migrate, and boreal and temperate species have generally survived by migrating. Given these facts, how do boreal species ensure their survival among the following options:
- Staying put
 - population movement
 - Leaving children behind
 - Earth's magnetic field
 - Going to work
 - food and shelter
 - genetic diversity
 - looseness of dirt or compost


 

    Earth's magnetic field     