cc-zeroNygård, ElisaNouhaud, PierreMartin-Roy, RaphaelKulmuni, Jonna2025-03-242021-09-042021-09-04https://hydatakatalogi-test-24.it.helsinki.fi/handle/123456789/8985Local populations can cope with rising temperatures, if they have adaptive potential to face the new thermal regime. Hybridization with a closely related lineage is one potential source of adaptive genetic variability and an outstanding question is whether hybridization could help contemporary populations to adapt in the face of current environmental change. We investigate thermal adaptation by testing for differences in cold and heat tolerances between Finnish populations of two mound-building wood ants, Formica polyctena and Formica aquilonia, and their naturally occurring hybrids. The results showed that parental individuals differed in both cold and heat tolerances and expressed thermal limits which reflect the global distributions of the parental species, in support to the thermal adaptation hypothesis. However, hybrids could not combine the thermal tolerance of both parental species as they were equally heat-tolerant to F. polyctena, but not equally cold-tolerant to F. aquilonia. Intriguingly, body weight had a significant role in thermal tolerance, with heavier ants coping better with higher temperatures. These results contribute to understanding the outcomes of hybridization and the potential that species possess in coping with environmental change. Wood ants are keystone species in the boreal forests and important for healthy forest ecosystems, but they are threatened by increasing global temperatures and habitat destruction. Our findings help to understand how these species may respond to global climate change.Opendataset