By Nneka Nwogwugwu
Sweating, headaches, fatigue, dehydration – the ways heat exhaustion affects the human body are well documented.
As temperatures inch up year by year we need to change the way we live, creating cooler places that provide refuge from heat.
But what about wildlife? We know mass die-offs are becoming more common as heat waves sweep terrestrial and marine ecosystems, but incremental increases in temperature, which are much harder to study, are harming almost all populations on our planet.
Earlier this year, for the first time, a paper was published on the impact of heat stress in large Arctic seabirds. Normally, research on species in that corner of the world is about adaptations to the cold, but in an era of climate chaos, learning to live with heat is the new challenge.
Emily Choy, a biologist from McGill University in Montreal, Canada, has been studying a colony of thick-billed murres on the cliffs of Coast Island in Hudson Bay after reports of birds dying in their nests on warm days. These black-plumed birds spend summer months perched on cliffs in full sun with little shade. Males and females alternate 12-hour shifts sitting on their eggs.
Their high metabolisms keep them warm when diving in waters that are 8C and cooler, so when faced with temperatures of 21C, the birds struggle to keep cool, panting and flapping their wings, according to the paper published in the Journal of Experimental Biology. As the Arctic warms at twice the global rate, these temperatures are becoming increasingly common.
“When we compared our data, we could really only do comparisons with desert species that are well adapted for heat,” says Choy. “Most of the work that has been done on thermal physiology in Arctic species has focused on heat conservation.
