Spontaneous discrimination of urine odours in wild African lions (Panthera leo)

Olfactory communication is the primary mode of communication for many mammals, yet research on this form of signalling is still largely descriptive in most species. Thus, despite the apparent importance of scent-marking in the social lives of wild felids, experimental studies directly investigating the function of olfactory communication are lacking. We conducted scent presentation experiments to investigate whether wild African lions can discriminate another lion's social group and sex from a sample of its urine. Our results indicated that lion urine has the potential to signal depositor sex and social group, and that lions can use urine to discriminate males from females and residents from non-residents. The response of lions to urine was also dependent on both the sex and age of the subject receiving the presentation. Female lions responded less frequently to urine from resident females than to either non-resident females or resident males. Males responded more strongly to urine from resident males than resident females, but did not appear to differentiate urine from non-resident and resident females. Observations of flehmen and further scent-marking responses from lions provide additional evidence that lion urine functions in scent-marking. These results establish that urine scent-marks contain sufficient information for receivers to discriminate the sex and social affiliation of the signaller, and are the first to experimentally demonstrate the functional relevance of scent-marking in African lions

Death Metal: Evidence for the impact of lead poisoning on childhood health within the Roman Empire

The use of lead was ubiquitous throughout the Roman Empire, including material for water pipes, eating vessels, medicine, and even as a sweetener for wine. The toxicity of lead is well established today, resulting in long-term psychological and neurological deficits as well as metabolic diseases. Children are particularly susceptible to the effects of lead, and it is likely that the widespread use of this deadly metal among Roman populations led to a range of adverse health effects. Indeed, lead poisoning has even been implicated in the downfall of the Roman Empire. This research examines, for the first time, the direct effect of lead poisoning on the inhabitants of the Empire. It explores whether the dramatic increase in lead during this period contributed to the failure to thrive evident within the skeletal remains of Roman children. Lead concentration and paleopathological analyses were used to explore the association between lead burdens and health during the Roman period. This study includes 173 individuals (66 adults and 107 non-adults) from five sites, AD 1st–4th centuries, located throughout the Roman Empire. Results show a negative correlation between age-at-death and core tooth enamel lead concentrations. Furthermore, higher lead concentrations were observed in children with skeletal evidence of metabolic disease than those without. This study provides the first bioarcheological evidence that lead poisoning was a contributing factor to the high infant mortality and childhood morbidity rates seen within the Roman world