Effects of group size, habitat type, and hunting risk on vigilance and feeding behaviour in the Lesser Rhea (Rhea pennata pennata)

BARRI, F., ; ROLDAN, N.; NAVARRO, J.L.; MARTELLA, M.B.

EMU

CSIRO PUBLISHING

Año: 2012 vol. 112 p. 67 - 70

0158-4197

 We studied the effects of group size, habitat type (shrubland steppe vs. meadows), and hunting risk (protected core area vs. edge area exposed to poaching) on vigilance and feeding behaviour of wild populations of the Lesser Rhea (Rhea pennata pennata), a “near threatened” ratite species, in northwestern Patagonia, Argentina. On average, Lesser Rheas allocated 18% of time to vigilance and 67% to feeding. Individuals tended to be more vigilant with declining group size, in areas with low visibility that hinders escape by running, and in areas exposed to hunting, than in open habitats with abundance of food resources or sites under low hunting risk. On the other hand, although time allocated to feeding was also influenced by habitat type and hunting risk, no direct relationship between feeding and group size was observed. As with other ratites species, the Lesser Rhea takes advantage of flocking as an anti-predation strategy.