Pocket Gophers May Be the First Non-Human Mammal to ‘Farm’ – Smithsonian Magazine

The gophers spend most of their time underground and only venture to the outside world to forage for food or mate. Veronica Selden/UF

Beneath North and Central American grasslands, pocket gophers dig labyrinths of winding tunnels hundreds of feet long. Now, researchers have found that the rodent architects may also be farmers, tendingto underground roots they harvest for food.

As the gophers construct their large tunnels, they turn over the soil, aerating it in the process, and munch on roots that grow and hang in the tunnels over time, reports Evrim Yazgin forCosmos. The behavior is not advanced agriculture, but it is a carefully managed food production system that provides the optimal conditions for root growth, Oliver Whang reports for theNew York Times. This week, details on the mammals root cropping behaviors were published inCurrent Biology.

Pocket gophers are brown rodents about the size of a Guinea pig. Their dietconsists of roots, stems,and some weeds and grasses above ground, reportsSciencesKatherine Irving. The gophers spend most of their time underground and only venture to the outside world to forage for food or mate.

To find out how and why the gophers construct large tunnels on their plant-based diets, scientists at the University of Floridadug trenches around three gopher tunnel sections in a Gainesville pastureand placed oil barrels at each trench to keep them out,Sciencereports. From here, the team photographed the blocked sections and noticed thatroots grew and filled the areas, whereas, in the places left open for the gophers to roam, the roots stayed short.

The researchersthen calculated the daily root growth to determinehow much of the gophers energy needs could be met by harvesting the roots, astatementexplains. Previously, it was thought that the gopherssurvived by eating away at roots they encountered while constructing their tunnels. Based on the calculations, the scientists found that the energy needed to dig a tunnel is too much to be supported by the roots that gophers eat while excavating it, but if they eat roots grown in other tunnels that are already dug, they can meet the energy expenditure, reports Sofia Quaglia forNational Geographic.

Through building and maintaining the extended networks of tunnels, the gophers create an environment for roots to thrive. The animals also scatter their poop and urine within the tunnels, which fertilize the growing roots, perNational Geographic. Theyre providing this perfect environment for roots to grow and fertilizing them with their waste, says Veronica Selden, a zoologistat the University of Florida and the studys first author, in a statement. When the potato-sized mammals nibble on the dangling roots, they also encourage growth.

Youre a small mammal going along, and you encounter a large root, and you bite it off, but its not very digestible because it has a lot of lignin or celluloses, its tough, its hard, says Francis Putz, an ecologist and study author at the University of Florida, toNational Geographic. But in response to being cropped, that root will make many small roots, and those will be really tasty and more digestible. By harvesting the root crops, the gophers can supply 21 to 62 percent of their energyneeds, making up the rest of the calories needed to continue their burrowing habits.

While some expertsargue that the gophers aren'ttechnically farming because they dont plant, weed or distribute their crops, the researchers involved in thisnew study think the finding opens upthepossibilitythat other ground-dwelling rodents could have behaviors that qualify as husbandry too.