Recent research has concluded that a strange burrowing rodent native to North America is technically the only non-human mammal to “grow” its food. Explanations.
Underground cultivators
The pocket waffles spend virtually their entire lives underground, digging multiple horizontal tunnels that can measure up to 160 meters in length. Since their diet consists mainly of plant roots, which they access through these galleries, scientists at the University of Florida wondered if the amount of energy expended to dig them did not exceed the contribution provided by the roots. standing in their way.
Another scenario suggests that the roots of the plants break through the walls of the tunnels already dug and that the ground squirrels return there punctually to consume them. The plants would survive this reduced length loss and would benefit from the nutrients contained in the excrement that the rodents spread in the galleries. The roots would grow further and spread out into the tunnel once more, giving them a new ” harvest ».
In order to test this hypothesis, Professor Jack Putz and zoologist Veronica Selden prevented ground squirrels from accessing a (limited) part of the sections of their galleries where the roots were exposed. Detailed in the review Current Biologythese experiments involved nearly 200 liter barrels (whose ends had been previously cut off), which were driven into the ground around the plants.
Revealing experiences
With the roots now protected, the scientists were able to precisely measure the speed at which they were growing, as well as the amount of energy they were capable of providing to rodents. According to their calculations, while regularly consuming the roots regrowing in existing tunnels gave ground squirrels enough energy to gradually expand their tunnel networks, the amount offered by their counterparts discovered by digging alone was largely insufficient.
« If agriculture requires crops to be planted, then ground squirrels cannot strictly speaking be considered cultivators “says Putz. ” But that seems like far too narrow a definition for anyone with a more horticultural view in which crops are carefully managed, like fruit trees in forests, but not necessarily planted.. »
