Test whether Rhytidoponera can execute behavioural retreat during extreme heat

Determine whether Rhytidoponera workers are unable to fully execute behavioural retreat during high-temperature exposure, thereby causing their elevated thermal sensitivity above the mortality plateau.

Background

Rhytidoponera shows elevated thermal sensitivity relative to the assemblage, including excess mortality during extreme heat events. The authors hypothesize that this vulnerability may result from an inability to fully retreat behaviourally, potentially because the lineage’s matinal activity schedule exposes workers to rapidly rising morning temperatures before retreat is possible.

This explanation is explicitly unresolved and requires direct behavioural testing to distinguish it from alternative physiological or ecological mechanisms.

References

Second, elevated thermal sensitivity in the Rhytidoponera lineage (excess hazard 5\,\% per \textdegree C) is consistent with some lineages being unable to fully execute behavioural retreat, possibly because their matinal schedule exposes them to morning temperature ramps before retreat is possible --- a hypothesis requiring direct behavioural testing.

— Body size predicts how long ant workers live - but not how they age or how they die from heat  (2608.14245 - Moscardi et al., 14 Aug 2026) in Discussion, Section 4.3, “Thermal risk is nonlinear — and the buffer is taxon-specific (Claim 3)”