Three days later, the story took an even stranger turn. Another olive ridley turtle came ashore near Huntington Beach, a few kilometres further south, and also dug into the sand to lay her eggs. Experts have since studied the photographs, particularly the shape of the carapaces and the arrangement of the barnacles: they were indeed two different females. Two turtles, two beaches, two nestings in less than a week. What might have been dismissed as an isolated navigational error suddenly began to look like something else.
Yet this species is not supposed to come and lay its eggs alongside the surfers at Huntington Beach. The olive ridley turtle lives mainly in the tropical regions of the Pacific, Indian and Atlantic Oceans. Its main breeding grounds in the eastern Pacific are much further south, notably in Mexico, Nicaragua, Costa Rica and Panama. Some Mexican beaches can even host hundreds of thousands of females during massive collective nesting events known as ‘arribadas’. Until now, olive ridley turtles would occasionally swim up into Californian waters, but they did not lay their eggs there.
The question is therefore simple: why now? And this is precisely where this little story about turtles ceases to be merely curious. Scientists do not yet have a definitive answer. Several hypotheses are being considered simultaneously: the powerful El Niño event currently underway, unusually warm waters, the aftermath of recent tropical storms, a navigational error or, more fundamentally, a gradual northward expansion of the species’ range. The Aquarium of the Pacific describes this as a ‘historic shift’ likely to have long-term consequences for turtle conservation and the management of California’s beaches.
We must, of course, avoid the oversimplification of treating two turtles as definitive proof of climate change. Biologists themselves remain cautious. But the event is unsettling because it forms part of a phenomenon now being observed across the globe: as temperatures change, the distribution maps of living organisms change with them. Fish, insects, birds and plants are gradually shifting their ranges. A species once considered tropical may appear a few hundred kilometres further north. An occasional sighting may become a regular occurrence. Then, one day, an animal is no longer content merely to pass through: it decides to raise its young there.
The two Californian nests were immediately fenced off and placed under surveillance. Incubation is expected to last around 45 to 60 days. If the eggs hatch, tiny turtles will emerge from the sand and attempt to make their way to the Pacific under the watchful eye of scientists. They would become the first known sea turtles to begin their lives naturally on a beach on the continental west coast of the United States. Their survival remains, of course, highly uncertain: among sea turtles, only a small proportion of hatchlings reach adulthood.
But what is truly fascinating lies elsewhere. The colonisation of a new territory sometimes begins exactly like this: an animal strays, finds a suitable spot, lays its eggs there, and then some of its descendants return years later. NOAA had already described this mechanism following the exceptional discovery of an olive ridley turtle nest in Hawaii: such irregular behaviour is precisely one of the ways in which a species can, over several generations, establish itself in a new region.
So here we have two turtles on two Californian beaches. It is almost nothing on a global scale. But it is sometimes from almost nothing that changes become visible. Whilst we draw borders, build cities and regard certain species as belonging permanently to certain regions of the globe, life continues to move. Perhaps these two turtles simply ended up on the wrong beach.
Perhaps, too, they have unwittingly shifted the map of the world by a few hundred kilometres.
