The New Encyclopaedia Britannica

activity America appear became become bill birds blood body Brazil breeding broadcasting Buddha Buddhist building called cause central century changes colour common contains continued countries early effect eggs established example Family feathers feeding feet female Figure forest fossil four ground head human important increased Indian industrial Italy known land later length less light lines living lower major male material metres natural nest normal North occur organizations originally pair pattern percent period petrels picture Pleistocene plumage political population present produced programs radio range receiver red cells region relatively remain result river short signal South specialized species structure surface tail television tion toes tradition trees tropical United usually varies various wide wings World young