alone
animal
ape
away
bars
behind
black
brown
cage
captive
captivity
capuchin
chimpanzee
depression
despair
endangered
environment
environmental
expression
expressive
eyes
face
fence
funny
gorilla
hair
hooded
iron
jail
jungle
locked
loneliness
lonely
mammal
metal
monkey
natural
nature
primate
prison
sad
sadness
small
solitude
thoughtful
trapped
tropical
wild
wildlife
zoo