英文關鍵字
abundant
america
bird
bred
breed
common
cone
danger
ears
eastern
eat
ecologically
environment
family
fed
feed
feeder
feeding
feeds
field
fight
fir
forest
genus
gray
grey
location
mammal
native
natural
nature
nest
nesting
north
nut
pair
peanut
pine
prodigious
regenerator
region
rodentia
safe
safety
sciurus
seed
species
squirrel
tail
territorial
territory
tree
wild
wildlife