africanelephant anatomy animal-plantrelationships animaldefenses animalpopulations animals bears birds botany botswana carnivorousanimals celebrations chobenationalpark dd9137 dinosaurs diseaseandpestresistance ecology edible effectofhumanbeingson elephants endangeredspecies environmentalconditions environmentaldegradation evolution food fossil granivores grasslandanimals grasslandecology greatplains histology history holidays human-animalrelationships humorousstories juvenilefiction juvenileliterature mammals mathematicalmodels nat046000nat044000nat003000 naturalhistory nature physiology picturebooksforchildren plantchemicaldefenses plantdefenses plantmetabolites plantpopulations plants populationbiology predation(biology) predatoryanimals prehistoriccreatures ql862l276m1988 rejuvenescence(botany) ruminant savannaecology stomach ungulates unitedstates valentine'sday vertebrates wildlifeconservation wolves zoology