Columbia subject headings:
Apes--Behavior.
Apes--Ecology.
Mammals--Behavior.
Mammals--Ecology.
Harvard subject headings:
Apes--Behavior
Apes--Ecology.
Mammals--Behavior
Mammals--Ecology
Princeton subject headings:
Apes--Behavior.
Apes--Ecology.
Mammals--Behavior.
Mammals--Ecology.