Mediterranean rangelands usually include woody vegetation
with mechanical and chemical defences against browsing. As
discussed by Papachristou et al. (2005), browse consumption
introduces new criteria for predicting diet selection, such as the presence of thorns or concentration of potentially toxic secondary
compounds (e.g. tannins, terpenes). Spinescence is
aimed at decreasing leaf and shoot losses for the plant. It
reduces the bite size and intake rate and increases the total
handling time, especially for large herbivores, by forcing the
animals to select the parts without thorns (Cooper and Owen-
Smith, 1986). In experimental trials involving penned animals,
a depressive effect of tannins on intake was observed and
related mainly to reduced palatability of feed due to tannin
astringency