Argentina 443 Buenos Aires [Argentina] South America 189 article 48 Atlantic Ocean 42 Buenos Aires 40 abundance 37 rodent 36 Mar del Plata 35 Pampas 33 Rodentia 32 Animals 31 morphology 31 Rio de la Plata 30 nonhuman 29 Gondwana 26 Western Hemisphere 25 World 25 seasonal variation 25 Aves 22 concentration (composition) 22 Atlantic Ocean (Southwest) 20 urban area 20 Animalia 19 Mammalia 19 Rivers 19 agricultural ecosystem 19 controlled study 19 phytoplankton 19 taxonomy 19