- Winter has cold temperatures
- Temperature is a property of the environment
- Hence, winter means cold environmental temperature

- Winter means cold environmental temperature
- An animal requires warmth for survival
- Hence, animals must move to a warmer environment during the winter

- Animals must move to a warmer environment during the winter
- Migration is when animals move themselves from a cooler climate to a warmer climate for the winter
- Therefore, an example of migration is moving to a warmer climate in the winter

- An example of migration is moving to a warmer climate in the winter
- Birds fly south for the winter
- Therefore, an example of migration is birds flying south in the winter

So, an example of migration is birds flying south in the winter
Some birds fly south before winter each year. This is an example of
- Winter has cold temperatures 
- Temperature is a property of the environment 
- Birds fly south for the winter 
- An animal requires warmth for survival 
- Migration is when animals move themselves from a cooler climate to a warmer climate for the winter