Tiny endangered pocket mice inherit their mothers’ fear of snakes. The discovery reveals that captive-bred individuals released as part of conservation strategies may not be entirely naïve to the dangers of the wild world. The Pacific pocket mouse (Perognathus longimembris pacificus) is considered endangered by the U.S. Fish and Wildlife Service due to its limited range and threats from habitat loss and degradation, among other challenges. To conserve the rodents, researchers are working on captive breeding programs. But training captive-bred rodents to avoid predators when they’re released is time-consuming. Researchers have now learned that by exposing pregnant Pacific pocket mouse mothers to threats from snakes, their offspring retain some of their learned fear. “Here we show, for the first time in an endangered mammal, that predator training of pregnant mothers can influence how their offspring respond to predators later in life,” said Debra Shier, the Brown endowed associate director of recovery ecology at the San Diego Zoo Wildlife Alliance in Escondido, California, and the senior author of the study published recently in Frontiers in Ecology and Evolution. So far, this fear is only inherited by female offspring, though researchers aren’t sure yet why.
