Fenología reproductiva y biometría de nidos, huevos y pollos del Ñandú, <i>Rhea americana</i> en Rio Grande do Sul, Brasil

The reproductive season of the Greater Rhea (Rhea americana) occurs at different times in the southern, central-western and northeastern states of Brazil. The start of reproduction in the Greater Rhea at Rio Grande do Sul shows a delay of approximately 30 days with relation to the populations in Central-east and North-east of Brazil. Males show a preference to build nests in fields of wheat and soybeans. Human and animal predation is the main cause of nest desertion by the incubating male, and the climatic variables are the most influential factors over hatching success and chick survival. The biometry of nests, eggs and chicks is discussed.