Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| EXAMPLE ORGANISM Noun phrase, subject of following verb phrase | EXAMPLE ACTIVITY Verb phrase for organism |  | ABSTRACT ACTIVITY Abstract description of organism performing an activity |
| --- | --- | --- | --- |
| A dog | burying a bone | is an example of an organism | storing nutrients for future use |
| A girl | eating an apple | is an example of an organism | taking in nutrients |
| An insect | crawling on a leaf | is an example of an organism | moving on a surface |
| A boy | planting tomatoes in a garden | is an example of an organism | cultivating nutrients |
| A squirrel | climbing a tree | is an example of an organism | moving in its habitat |
| A rabbit | feeding its young | is an example of an organism | providing nutrients to its offspring |
| A frog | eating an insect | is an example of an organism | ingesting nutrients |
| A bird | migrating south | is an example of an organism | adapting to change in the environment |
| A bat | flying at night | is an example of an organism | moving |
| A deer | drinking water | is an example of an organism | ingesting water |
| An owl | eating a mouse | is an example of an organism | ingesting nutrients |
| A squirrel | storing nuts | is an example of an organism | preparing for a seasonal change in its environment |
| A whale | spouting | is an example of an organism | breathing |
| Maple keys | spinning through the air | is an example of an organism | reproducing |
| Leaves | falling from an oak tree | is an example of an organism | eliminating waste |
| A turtle | eating worms | is an example of an organism | taking in nutrients |
| Some birds | flying south before winter each year | is an example of an organism | migrating |
| Some mammals | sleeping through the winter each year | is an example of an organism | hibernating |
| Some seeds | sprouting after they have been exposed to fire | is an example of an organism | germinating |
| Bears | going into a kind of sleep during winter to reduce their need for food | is an example of an organism | hibernating |
| Canadian geese | flying south during winter to avoid the cold | is an example of an organism | migrating |
| A white arctic fox | blending in with the snow | is an example of an organism | using camouflage |
| Some butterflies | living an average of two weeks | is an example of an organism | living a life span |
Question:
What organism demonstrates migration by flying south before winter? Select the correct choice to answer the question or fill in the blank.
Choices:
(A) squirrel
(B) birds
(C) seeds
(D) whale
Answer:
(B) birds