sentences:  The most common of these, the Lenga beech, was also a primary food item of the red deer, causing displacement to marginal areas and increased vulnerability for the smaller South Andean Deer.Both decreased reproduction rates and increased morbidity may be affecting the population in Argentina; predation by the cougar, the South Andean deer's only natural predator, remains a principal cause of mortality in Argentina.According to the International Union for the Conservation of Nature (IUCN), the species’ original global population is estimated to have suffered reductions of 99 per cent in size and more than 50 per cent in distribution range.