Disentangling the impacts of climate and human colonization on the flora and fauna of the Australian arid zone over the past 100 ka using stable isotopes in avian eggshell

•Five 100 ka δ13C time series in Dromaius eggshell show abrupt ecosystem collapse 50 ka.•δ18O in the same samples show no climate change then.•Human agency is the most likely cause, plausibly due to a changed fire regime.