In 2019, University of Washington researchers witnessed the consequences of an extreme heat event in Argentina at one of the world’s largest breeding colonies for Magellanic penguins. On Jan. 19, temperatures at the site in Punta Tombo, on Argentina’s southern coast, spiked in the shade to 44 C, or 111.2 F. As the team reports in a paper published Jan. 4 in the journal Ornithological Applications, the extreme heat wave killed at least 354 penguins, based on a search for bodies by UW researchers in the days following the record high temperature. Nearly three-quarters of the penguins that died — 264 — were adults, many of which likely died of dehydration, based on postmortem analyses.