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Lonesome George, the last of the Pinta Island tortoises, died in 2012, leaving no offspring. His solitude was imposed upon him by humans who killed the rest of his species and brought goats to his island in the Galapagos, destroying their habitat. But Lonesome George probably didn’t much mind being on his own. Tortoises are generally solitary, coming together only to mate. The same is true of most reptiles and even many mammals, including bears, moose, tigers, sloths, platypuses, rhinos and pangolins.
As social creatures ourselves, it is only natural that we are fascinated by animal societies, from wolf packs to ant colonies. But to understand sociality, we must look at the flip side: why do some animals prefer to go it alone? Surprisingly, researchers have paid little attention to this question. “People are only interested in group-living species with complex societies,” says Carsten Schradin at the Hubert Curien Pluridisciplinary Institute in Strasbourg, France. “But if you don’t understand why, in many cases, solitary living is the better solution, you also miss a total understanding of group living.”
Now, Schradin and a handful of pioneering biologists are addressing this oversight. Already, their research reveals that being solitary isn’t simply the ancestral lifestyle for mammals, but an evolved strategy, a specialised way of living, with its own pros and cons. What’s more, animals considered solitary aren’t necessarily antisocial: it turns out that many of them have structured social networks, even if they spend most of their time by themselves. These creatures give us a new perspective…
