Diferential aversive responses to novelty in two sympatric foxes at southern Patagonia: implicancies for improving selective control methods

SIGRID NIELSEN; ALEJANDRO TRAVAINI; ALDO IVÁN VASSALLO; GERMÁN OSCAR GARCÍA; ALEJANDRA ISABEL ECHEVERRÍA; SONIA ZAPATA

Bahía Blanca

Jornada; XVIII Jornadas Argentinas de Mastozoología; 2010

SAREM

Neophobia, or the hesitancy to approach a novel food item, object, or place, is an important factor influencing investigative and innovative animal behavior and its incorporation in selective predator control techniques may be of great interest. In this study, we simultaneously evaluated the existence and intensity of neophobic responses in two sympatric fox species, the Culpeo Pseudalopex culpaeus and the Grey fox P. griseus at the “Monumento Natural Bosques Petrificados”, in southern Patagonia. For this purpose, we used bait-stations and compared behavioral responses in absence (pre-treatment), presence (treatment) and removal (post-treatment) of a novel stimulus, which consisted of an orange PVC-75 cm tall vial cone. We established 19 transects, each one composed by 6 bait stations. A bait station consisted of a 1-m-diameter circle of smoothed earth with the bait placed at the centre. Stations were spaced by 0.5 km apart and transects were at least 1 km apart. We detected a neophobic response in both fox species. The comparison between treatment and pre-treatment conditions showed for both Culpeo and Grey foxes that visitation rates decreased in presence of a novel object, but Culpeo fox showed a relatively strong neophobic response toward novel objects as compared to Grey fox (Culpeo foxes mean visitation rate 0.025 (treatment) vs. 0.114 (pre-treatment), N = 20 and N = 19 respectively, and Grey foxes 0.817 (treatment) vs. 0.914 (pre-treatment), N = 16 and N = 14 respectively). The opposite happened during post-treatment, where individuals showed an increase in site exploration, as indicated by a significant increase of bait station use and number of tracks left inside it. We suggest that manipulating fox behavior has promising utilities in improving selective and efficient control methods for Culpeo foxes throughout those areas where it lives in sympatry with the non target Grey fox.