Reliability of δ13C and δ15N in faeces for reconstructing savanna herbivore diet

摘要: We tested the reliability of herbivore faecal δ13C and δ15N values for reconstructing diet through review an extensive database derived from a 3-year study ungulates in South Africa's Kruger National Park. Faeces are useful material stable isotope studies because they record dietary turnover at very short time scales, sampling is non-invasive. However, validity proxies may be questioned represent only undigested food remains. Results Park confirm that free-ranging browsers have consistent with C3 feeding, grazer faeces C4, mixed-feeder intermediate. Although respective ranges do not overlap, there significant variation grazers (∼2.0–4.0‰) across space time. demonstrate most (∼70%) this can ascribed to corresponding patterns C4 plants, respectively, re-enforcing fidelity but highlighting need mixing models control variations plant order achieve accurate reconstructions. Predictions effects climate (rainfall) ecophysiology on 15N-abundance mammals persist faeces. Rather, tracks changes δ15N, further fractionation occurring primarily due protein (reflected by %N). Controlling these effects, we show dual-isotope multiple source model (Isosource) extend reconstructions African savanna herbivores beyond simplified C3/C4 distinctions, although understanding mammal needed greater confidence approach.