Answer:
Hippocampus
Step-by-step explanation:
The hippocampus is a portion of the brain that plays a major role in the ability to recall past events. It helps in the storage of important information that can be useful later in the future. If this portion of the brain is absent then, it will be difficult to remember or recollect past events.
In the scenario described above, the chikadees and other birds that store food in various location will not be able to remember where the food is stored again after several months if the hippocampus is removed from their brain. This is because they have lost the ability to recall where the food particles were initially kept.