Native and no-native herbivorous relationships have mutual benefit: Lepus flavigularis case

Abstract

Lepus flavigularis is an endemic leporid from southeastern Oaxaca, México, listed as “endangered” under Mexican law and the IUCN Red List.  The main threat to the species is severe habitat fragmentation due to human activities.  The jackrabbit shares the grasslands with cattle (Bos taurus), but the trophic interaction between these herbivores is unknown.  This study aimed to determine the seasonal diet of Lepus flavigularis and cattle, to identify the possible dietary overlap between these mammals.  The study zone covers an area around the locality of Santa María del Mar in Oaxaca, southern México.  Plant species were identified using linear transects, and vegetation cover was also estimated using circular plots.  Throughout the study fresh L. flavigularis and B. taurus fecal samples were collected, which were processed using the microhistological technique to determine the seasonal botanical composition of diets from the two species.  Twenty-three plant species were recorded in the diet of L. flavigularis and 29 species in the diet of B. taurus.  Both herbivores fed primarily on Poaceae species throughout the year (L. flavigularis: dry season (ds) = 79.79 %, wet season (ws) = 91.54 %; B. taurus: ds = 78.02 %, ws = 84.63 %) despite the significant difference in the availability of plant species between seasons.  No significant differences were found in the seasonal composition of the diet between the two species.  Twelve plant species were consumed by both herbivores during the two seasons.  The dietary overlap between the two species was high for both seasons (ds Ojk = 0.7311, ws Ojk = 0.8459).  Trophic niche breadth was low for both species, with a high dietary overlap.  We recorded low seasonal use values for L. flavigularis and B. taurus when compared to forage availability.  Low trophic niche breadth and high dietary overlap between the two herbivores suggest forage resources competition. However, we expect that jackrabbits benefit from cattle presence, as long as the stocking rate does not increase.  Furthermore, B. taurus grazing reduces height, cover, and density of vegetation, which could help L. flavigularis to avoid predators.