Ewes behavioural and physiological reactions to the odour of fox (Lycalopex gymnocercus) and wild boar (Sus scrofa) faeces

Abstract

Predation of sheep is a production problem that deserves the studies of how this prey species detects and react to predators. In this context, this study determined the behavioural and physiological responses of ewes exposed to the odour of predators’ faeces as fox (Lycalopex gymnocercus) and wild boar (Sus scrofa). Four experimental treatments were applied to 48 Corriedale sheep (12 ewes each): fox faeces (FFO), wild boar faeces (WBFO), unknown sheep wool (SWOC) and no odour (NOC). All ewes were evaluated in a behavioural test for 5 min and then rectal temperature was measured, and a series of blood samples were obtained to determine cortisol concentration, glycaemia, total protein, albumin and globulin. The frequency of kicking the ground, turning their head, going back and stillness behaviours increased significantly in FFO in comparison with NOC (p = 0.01; p < 0.0001; p = 0.005 and p = 0.002, respectively) and kicking the ground and turning the head compared with SWOC (p = 0.03 and p < 0.001 respectively). The FFO group spent significantly more time turning the head and going back than NOC (p < 0.001 and p = 0.01 respectively) and SWOC (p = 0.002 and p = 0.05). For ewes evaluated with WBFO, kicking the ground, turning their head, going back and remaining still occurred significantly more times than with NOC (p = 0.008; p = 0.005; p = 0.01 and p = 0.003), and kicking the ground, turning their head and remaining still occurred significantly more times than with SWOC (p = 0.02; p = 0.02 and p = 0.05). Furthermore, WBFO group spent significantly less time still (p = 0.01) and more time turning their head and going back (p = 0.001 and p = 0.02, respectively) than NOC, that spent significantly more time turning their head than SWOC (p = 0.006). Rectal temperature and haematological variables were not affected by treatments. The increase in the frequency of agonistic behaviours and duration of locomotion behaviours in ewes treated with predators’ faeces, allow us to conclude that ewes respond to fox and wild boar’s faeces exposure with a similar aversive behavioural repertoire. Also, ewes displayed some physiological responses although these responses cannot be attributed to the odour of predators.