Sex differences in feed intake, behaviour and weight gained by greater Rheas (Rhea americana) in captivity during the pre-reproductive season

SIMOY, M. VERÓNICA; MILANO, FERNANDO; MARINELLI, CLAUDIA B,; FERNÁNDEZ, GUSTAVO J.; CANZIANI, GRACIELA

JOURNAL OF BIOLOGICAL SYSTEMS

WORLD SCIENTIFIC PUBL CO PTE LTD

Lugar: London, UK; Año: 2015 vol. 23 p. 123 - 133

0218-3390

The use of common rhea, Rhea americana, as breeding bird requires knowledge of nutritionalphysiology. It is important the analysis jointly of feed intake, behavior and weightgain. Our objective was to determine and analyze differences in the feed intake, weightgained and behavior of captive subadults and adults male and female rheas duringautumn and winter in the Humid Pampas, Argentina. Neither males nor females showedsignificant seasonal differences in the weights with which they initiated the trials. Dailyfeed consumption didn?t show significant differences neither between seasons nor betweensexes. However, we observed differences in weight gain by males between seasons andduring the autumn trial, the weight gain was higher for males. Rhea behavior also variedseasonally. Males and females spent more time preening and resting than walkingand feeding during autumn, the opposite occurred in winter. The males had a highertendency towards walking than to feeding, the females showed the opposite in autumn.Analyzing the feed intake, weight gained and the time spent on feeding we hypothesizedthat males are more efficient for feeding. This analysis allowed us to observe there arenutritional issues that can be explained from a behavioral point of view.