Different factors that modify anti-predator behaviour in guanacos (Lama guanicoe)

P. TARABORELLI; R. OVEJERO; M. EUGENIA MOSCA TORRES; N. M. SCHROEDER; P. MORENO; P. GREGORIO; E. MARCOTTI; A. MAROZZI; P. CARMANCHAHI

ACTA THERIOLOGICA

POLISH ACAD SCIENCES

Lugar: Bialowieza; Año: 2014 p. 1 - 11

0001-7051

Animals optimize the trade-off between the cost ofnot fleeing and the benefits of staying because the factors thatinfluence flight decisions and the disturbance level of a particularstimulus can vary both spatially and temporally.Different factors (human impact and habitat characteristics)likely to modify anti-predator behaviour in different types ofguanaco social groups were analysed. We found that groupsize was conditioned by high poaching, vehicle traffic,predation risk and vegetation density. Solitary adult malesshowed shorter alert and flight initiation distances than bachelorand mixed groups. Alert distance was greater during thesummer season, and assessment times were shorter whenyoung were present in the groups. In high-predation-riskenvironments, guanacos detected threats at greater distancesand flight initiation distance was longer. Alert distances wereshorter on steeper sloped hills and assessment times wereshorter in areas with irregular topography than on flat sites.In high traffic areas, flight initiation distance was longer andassessment times were shorter. And in areas with lowpoaching intensity, assessment times were greater than inthose with high poaching levels. Therefore, guanacos maybe able to evaluate a true threat. Social group and antipredatorresponses were conditioned by habitat characteristicsand human impact. We consider that plasticity of responsescould be key to the survival of guanacos.