Seabirds such as albatrosses and petrels are retreating into smaller areas of ocean and travelling further to find new places to live as the climate warms.
Scientists from the University of Reading studied more than 120 species of Procellariiformes (the group that includes albatrosses, petrels, shearwaters and storm petrels) using evolutionary family trees, ancient climate records and ocean temperature data to track how their ranges and movements have changed throughout history.
The first-of-its-kind research, published today (Tuesday, 19 May) in Nature Climate Change, found that when temperatures rose rapidly in the past, seabirds did not get smaller, as some fish and other ocean creatures do. Instead, they shrank their territories and flew greater distances to reach suitable habitats.
Dr Jorge Avaria-Llautureo, who led the study from the University of Reading, said: "Seabirds have survived dramatic climate shifts before, but never at the speed we are seeing today. We can see from history that when temperatures rise quickly, these birds do not adapt physically. Instead, they are forced to abandon parts of their range and travel further to survive. Conservation efforts need to focus not just on protecting the places where seabirds live now, but on safeguarding the places they will need to reach in the future."
Speed matters more than direction
How fast the climate changes matters more than whether it gets warmer or cooler, the study found. Species exposed to the most rapid historical temperature shifts ended up with the smallest ranges and travelled the farthest. The rate of temperature change alone accounted for 35% of the variation in range size across the species studied.
Today's oceans are warming around 10,000 times faster than the rates seabirds have adapted to over millions of years. Seabirds have historically coped with warming of around 0.00002°C per decade; current ocean warming is running at around 0.13°C per decade.
New statistical models developed at the University of Reading, which can track where seabirds lived through millions of years of climate shifts, were used for the first time to inform predictions on how ranges might change by 2100.
Under a lower-emissions future, fewer species are affected and range losses are smaller. Under the worst-case warming scenario, more than 70% of species are expected to contract their ranges, with those losing the most ground forced to travel the greatest distances to survive. Four species face a real risk of extinction under this scenario:
Seabirds are already among the most threatened groups of birds on Earth and play important roles in ocean ecosystems, including cycling nutrients and supporting fisheries.
