environmental
alone
animal
annoyed
ape
bar
bars
behind
brown
cage
caged
captive
captivity
captured
child
chimpanzee
concept
creature
depression
environment
exhibit
face
fence
freedom
gorilla
iron
jail
locked
lonely
look
mammal
metal
monkey
natural
nature
portrait
primate
prison
sad
sadness
solitude
species
suffer
survive
term
tropical
wild
wildlife
young
zoo