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A study was conducted to assess the hypothesis that llamas (L) grazing effects on soil infiltration rate and soil moisture are lower than cattle (C) grazing because llamas have a lower impact on key soil and vegetation variables associated to rangeland hydrological function. Two ecological sites were selected, one dominated by�Festuca humilior�and�Carex ecuadorica (Fehu-Caec)�in regular condition (RS), and the other dominated by�Calamagrostis macrophylla�and�Stipa brachiphylla (Cama-Stibra) in poor condition (PS), both sites managed under high intensity rotational deferred grazing system. Changes in biomass, litter, soil bulk density, soil infiltration rate, and soil moisture were assessed. Measurements were taken at the end of the deferment period and after each grazing period. The results revealed that in both sites (RS and PS) soil compaction was higher with cattle than with llamas (0.88 g ? cc-1 vs. 0.86 g ? cc-1, p < 0.01). There was no difference (p > 0.05) in infiltration rate (L, PS: 0.14 and RS: 0.18 cm ? min-1) vs. (C, PS: 0.06 and RS: 0.17 cm ? min-1) despite the fact that llamas grazing was more beneficial. Soil moisture, a key variable, was higher under llama grazing than with cattle (p < 0.01) (L, 29 % vs. C, 26 %), an outcome that was attributed to the higher amount of residual biomass that llamas left after grazing compared to cattle because eat less per unit weight than cattle. We conclude that American Camelids have lower impact on rangeland hydrological function than cattle do.