"these birds" - related articles and key terms

Related terms: buff   pale   nest   flock   weigh   prey   eggs   tail   birds   pairs   call   darker   seeds   feather   adult   genus   habitat   migratory   intergrades   breeding   distinct   migration   sandhill crane   subspecies   pdf fulltext   endangered   canada   species   north america   national wildlife refuge

Wikipedia sources: Barn Owl   Mourning Dove   Whooping Crane   Sandhill Crane   Great Horned Owl   Black-capped Chickadee

Context for words: these   birds