Stable isotopes reveal seasonal competition for resources between late Pleistocene bison (Bison) and horse (Equus) from Rancho La Brea, southern California

Stable isotopes of fossil teeth corroborate key general circulation model predictions for the Last Glacial Maximum in North America

“…18 O values from Florida (−1.5‰ ]), Arizona (−5.5‰ [Higgins and MacFadden, 2004]) and southern California (−8‰ [Feranec et al, 2009]) are also similar to or higher than modern estimates: −3.5, −8.0, and −7.5‰, respectively (data from Coplen andKendall [2000] andFriedman [2000]). The main question, however, is the degree to which such high d 18 O moisture penetrated northwards.…”

“…Isotope data from Florida, Texas, Arizona, and southern California have already been published [Koch et al, , 2004Higgins and MacFadden, 2004;Feranec et al, 2009], but were not interpreted within the context of GCMs. Key new data include specimens from a stratified cave deposit at Natural Trap Cave (NTC), located ∼200 km NNE of the WRT; this area is well within the region of NCAR-CCSM OAGCM-predicted decreased precipitation and d…”

The use of δ13C values of leporid teeth as indicators of past vegetation

“…To date, most stable isotope studies of herbivore teeth have focused on the teeth of large, herbivorous mammals because the enamel is both easy to sample and its isotopic composition integrates diet over at least a year (Cerling and Sharp, 1996;Hoppe et al, 2004;Feranec et al, 2009). Though they are less well studied, small mammals are increasingly being used to tackle questions about paleoenvironmental change (e.g., Rogers and Wang, 2002;Feranec et al, 2010;McLean and Emslie, 2012;Hynek et al, 2012).…”

“…Small mammals also are typically non-migratory, ensuring that δ 13 C values do not reflect a mixed signal associated with changes in the isotopic composition of vegetation across regional climate gradients. For example, leporid lagomorphs (rabbits and hares) typically spend their lives in areas 0.4-200 ha in size (McNab 1963;Chapman and Willner 1978), but large mammals such as Bison have modern home ranges several orders of magnitude larger (Larter and Gates, 1994), and are known to migrate long distances (Morgan, 1980;Feranec et al, 2009). Leporids also often are generalist herbivores (Feldhamer et al, 2003), so their teeth reflect a more representative proportion of the extant vegetation, namely low lying herbaceous plants, than large, grazing herbivores, such as Bison and Equus, which primarily consume grasses (Feldhamer et al, 2003).…”

Extinción de Equidae y Proboscidea en América del Sur. Un test usando datos de isótopos de carbono

“…Isotopic analyses can reveal information about resource use and resource partitioning among species and is also able to determine diet and habitat use (Tütken & Vennemann, 2009;Feranec et al, 2009). In this study, the diets of gomphotheres and horses from South America are assessed using carbon isotope analysis to test both hypotheses for extinction.…”