The dwindling North Atlantic right whale population is on track to finish its breeding season without any new births, prompting experts to warn again that without human intervention, the species will face extinction.
Scientists observing the whale community off the US east coast have not recorded a single mother-calf pair this winter. Last year saw a record number of deaths in the population. Threats to the whales include entanglement in lobster fishing ropes and an increasing struggle to find food in abnormally warm waters.
The combination of rising mortality and declining fertility is now seen as potentially catastrophic. There are estimated to be as few as 430 North Atlantic right whales left in the world, including just 100 potential mothers.
“At the rate we are killing them off, this 100 females will be gone in 20 years,” said Mark Baumgartner, a marine ecologist at the Woods Hole Oceanographic Institution in Massachusetts. Without action, he warned, North Atlantic right whales will be functionally extinct by 2040.
Their little chicks fast for more than a week while they forage for fish and krill in the waters of the Antarctic polar front, an upwelling where cold, deep seas mix with more temperate seas.
And while king penguins, the second largest penguin species, can swim a 400-mile round trip during that time, they are traveling farther and farther from their nests on the islands near Antarctica, endangering their hungry offspring.
As with so many other species, warmer temperatures are threatening this population, and a new study published today in Nature Climate Change warns that 70 percent of the 1.6 million estimated breeding pairs of king penguins could be affected in this century.
“They will need to either move somewhere else or they will just disappear,” said Emiliano Trucchi, one of the paper’s senior authors. “The largest colonies are on islands that will be too far from the source of food,” predicted Dr. Trucchi, an evolutionary biologist at the University of Ferrara in Italy.
The research team developed a model to predict which islands would become vulnerable with warming, and which ones might become better habitats. They then validated their model through historical and genetic data, reconstructing king penguin relocations during previous periods of climate change.
About half of the king penguin population nests on the Crozet and Prince Edward Islands, in the Indian Ocean south of Madagascar, and are projected to lose their habitat by 2100, according to the model. The 21 percent that nest on the Kerguelen Islands in the Indian Ocean and the Falkland and Tierra del Fuego islands close to South America would find their nesting grounds altered and would have to travel farther to find food and so might relocate. But, the researchers said, some of that would be offset by the colonization of Bouvet Island and a few other islands.
Several others are likely to become more habitable, according to the research. But unlike their bigger cousins the emperor penguins, king penguins can’t nest on ice so their choices are limited and may be hundreds or even thousands of miles from their current nesting areas.