02035nas a2200169   4500008004100000245010400041210006900145300000900214490000600223520145600229100002301685700002301708700001701731700002001748700001901768856007801787       2013                        eng d00aIdentifying the water sources consumed by bison: implications for large mammalian grazers worldwide0 aIdentifying the water sources consumed by bison implications for  a23 -0 v43 a<p>The sources of drinking water consumed by grazers vary over time and may be highly selective, similar to choices in diet. Water sources consumed by large grazers in natural populations are not typically measured directly. Instead, consumption is inferred based on animal proximity to water sources. Here, we analysed the stable isotopic signature of water (δ18O and δD) extracted from fecal samples from a herd of bison in mesic grassland as a direct estimation of the water sources consumed over time. Bison at this site have their choice of a range of habitats and drinking water sources. Potential source-water samples measured had a large range of isotopic signatures, allowing the isotopic composition of water from bison fecal samples to be proportionally estimated based on varying sources. Results indicate bison have low reliance on multiple streams on site; rather, the majority of water consumed was from rainfall-fed sources (puddles and wallows) and from forage. Our research suggests that source-water analysis from fecal samples is a robust technique when samples from large grazers can be collected soon after production. These results have implications for analyses of the foraging patterns and landscape utilization by this and other large grazers, because hotter and drier future conditions are likely to reduce the frequency and amount of rainfall-fed puddles available for consumption in many grassland systems worldwide.</p>1 aNippert, Jesse, B.1 aCulbertson, T.S.F.1 aOrozco, G.L.1 aOcheltree, T.W.1 aHelliker, B.R.  uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES12-00359.1