Naked mole-rats employ a normoxic escape behaviour that is altered by social interaction

Escape behaviours are a common response when animals encounter hypoxic environments. Confoundingly, naked mole-rats (NMRs) experience hypoxia while sleeping in crowded colony nest chambers, from which escape may not be desirable. In isolation, individual NMRs decrease physical activity to save energy in hypoxia, but this response is absent when conspecifics are present. However, whether NMRs try to escape hypoxia is unknown, as is the impact of sociality on any hypoxic escape behaviours. We predicted that individual NMRs would try to escape from hypoxic environments, but that sociality would reduce the drive to escape. We allowed individual and paired NMRs to choose between normoxia (21% O₂) or various depths of hypoxia (3%, 7% or 11% O₂) and non-invasively recorded their activity. Surprisingly, individual NMRs exhibited a novel normoxic escape behaviour and preferred severe hypoxia (3% O₂) to a normoxic environment. This preference was not repeated in less severe levels of hypoxia. Paired animals also preferred a hypoxic environment over normoxia, but social interactions drove an increase in movement velocity and reduced the severity of their preferred level of environmental hypoxia to 7% O₂. Thus, NMRs choose hypoxic environments over normoxic environments and sociality impacts this behavioural choice in hypoxia.