- Winter has cold temperatures
- Temperature is a property of the environment
- So, an environment is cold in the winter

- An environment is cold in the winter
- Cold environments usually have little food for animals
- So, an environment usually has little food for animals in the winter

- An environment usually has little food for animals in the winter
- Animals require food to survive
- Hence, animals must move to an environment with more food in the winter

- Animals must move to an environment with more food in the winter
- A warm environment usually has more food than a cold environment
- So, animals must move to a warmer environment during the winter to find food

So, animals must move to a warmer environment during the winter to find food
Question
Which of the following best explains why many species of birds in New England fly south for the winter months?

Context
- Winter has cold temperatures 
- Cold environments usually have little food for animals 
- Temperature is a property of the environment 
- Animals require food to survive 
- A warm environment usually has more food than a cold environment