Life
Food-storing tayras, stay-at-home finch dads and ant sex scandals in this week's news
Farmer-ant sex scandal
Ants heralded as thriving without males or sex turn out to practice sex after all in parts of their range. Asexual animals intrigue biologists because these species are in the minority despite having the advantage that any individual, not just a female, can have babies. The ant Mycocepurus smithii forms all-girl farms that cultivate fungi as food throughout much of Latin America. Genetic analysis has now detected signatures of sexual reproduction in some populations of the species in the Amazon Basin. Researchers haven’t collected a male but have found otherwise hard-to-explain sperm, an international research team reports online July 18 in the Proceedings of the National Academy of Sciences. —Susan Milius
Finches without mommas
A male zebra finch can feed and raise his offspring by himself if need be, but his babies may grow up to respond to stress a bit differently from chicks in two-parent nests. Adult finches raised by single dads showed an unusually prolonged rise in stress hormone production when isolated for 30 minutes. Earlier work on rats had shown that effects of maternal absences persist in adulthood. The results suggest that birds too show long-lasting effects of early parenting, Cornell researchers report online July 20 in the Proceedings of the Royal Society B. —Susan Milius
Tayras shop smart
Weasel-like tayras that pick and cache unripe tropical fruit may count as a new example of animals that can take future circumstances into account. Cameras as well as researcher observations have documented tayras collecting both plantains and sapote fruits that had achieved their full size but hadn’t sweetened to prime ripeness yet. Instead of eating these finds on the spot, tayras cached them, and observers have also seen the animals feasting on fruit caches. Animals that collect and store food can get a big advantage for survival. Tayras may inspire a new line of research on cognitive abilities, researchers in Costa Rica and Australia suggest in an upcoming Naturwissenschaften. —Susan Milius
