Poachers target older elephants for ivory because their tusks are larger. Elephants live in groups led by older females, and their loss may drastically affect the social structures of these communities.

Yet elephant societies managed to survive the loss of their matriarchs, a study found.

“We were expecting some sort of social collapse, especially knowing how important matriarchs are to a society,” said Shifra Goldenberg, a wildlife ecologist doctoral candidate at Colorado State University and an author of the new report, which was published in Current Biology.

Instead, the researchers found that after the loss of a matriarch, female offspring often stepped in and leveraged their mother’s contacts to rebuild social networks. (The study did not track adult males.) “We thought we’d be seeing a bunch of kids running around that don’t have much guidance,” Goldenberg said. “But the story here is that they are figuring it out. They just need a bit of time.”

 

Snail sex change cued by touch

Clownfish do it, wrasses do it, and sometimes even chickens do it. Animals that spontaneously change sex are probably more common than you think. After all, the ability to change the sex ratio of a species based on environmental factors makes way more sense than the system we’ve got going on.

A study from the Smithsonian Tropical Research Institute examined the oil’ sex switcheroo in one species in particular and found a surprising trigger: touch.

It makes sense for bigger tropical slipper limpets (Crepidula marginalis) to become female. Because eggs take more energy to produce than sperm, a bigger mollusk will be more capable of reproductive success as a mom than a small one. In fact, females of the species play host to multiple males that live on their backs. But how does a snail’s body know that the time is right to make that change? Some kind of inter-animal communication must occur that “tells” a snail that it has reached the right relative size to become a mom.

STRI staff scientist Rachel Collin and former intern Allan Carrillo-Baltodano, now a pre-doctoral student at Clark University, found that the snail seems to use physical contact with other members of its species to guide sex change. The researchers aren’t entirely sure what the mechanism behind this strange cue is.

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