Dietary overlap of coexisting exotic brown hare (Lepus europaeus) and endemic mara (Dolichotis patagonum) in Northern Patagonia (Mendoza, Argentina)

PUIG, S.; CONA, M.I.; VIDELA, F.; MÉNDEZ, E.

MAMMALIA

WALTER DE GRUYTER & CO

Lugar: Berlin; Año: 2014

0025-1461

Introduced brown hares are present across thedistribution range of maras, which are endemic to Argen-tina?s open steppes. Food competition with exotic herbi-vores could be partially responsible for declines in marapopulations. Diets of sympatric hares and maras werecompared to detect dietary overlap according to foodavailability. Diets and availability were estimated usingmicrohistological analysis and point-quadrat transects,over four seasons. Horn?s index estimated dietary overlap,Kruskal-Wallis ANOVA detected significant differences,and permutational multivariate analysis of variance (Per-MANOVA) determined the multivariate response to fac-tors. Grasses prevailed among available items and in bothdiets. Plant cover and richness increased in summer andforbs in spring. High dietary overlap decreased in autumn-winter, when hares ate more forbs and tall shrubs and lesslow shrubs than maras. Interspecific overlap was higherinside a protected area with higher food diversity, moreforbs, and low shrubs. Both herbivores shifted to differ-ent foods as availability decreased. When forbs declined,they were less eaten by maras than hares. Broader habi-tat use allows hares to search for preferred forbs fartheraway than maras. The more adaptive hare could becomea stronger competitor in impacted environments. Betterfood availability inside than outside the protected area is afeeding advantage for the coexistence of these herbivores.