Behavioral responses to cold stress vary during poleward range expansion of <i>Nerita yoldii</i>

Here, we examined boldness and locomotor performance under acute cold stress in the intertidal snail <i>Nerita yoldii</i>, which has recently expanded northward along the Chinese coastline into cold‐temperate regions.

Using six populations spanning the historical and expanded ranges, we combined simulated winter body temperature with controlled cold‐stress experiments to quantify emergence latency as an index of boldness and movement distance as a measure of locomotor performance. Northern expanding populations experienced colder winters and more frequent extreme cold events than southern historical populations. Boldness before cold exposure did not differ significantly among populations, but changes in boldness following cold exposure were population specific: the recently established populations maintained relatively stable boldness, whereas the historical-range populations became significantly shyer.