TAPACHULA, Mexico – Most people wouldn’t dare step off the trail and climb several feet down a steep ravine covered in thick foliage – excellent cover for the poisonous snakes common here in the mountains of southern Mexico.

But it doesn’t seem to bother Beatriz Otero-Jimenez. Wearing tall rubber boots, she fearlessly wades into the weeds to do something that many would find just as terrifying or repulsive: catching rats and mice.

“I worked with frogs before I came here, listening to their calls. This is my first experience handling animals in the field,” said Otero-Jimenez, a third-year doctoral student in ecology and evolutionary biology at the University of Michigan.

This summer, Otero-Jimenez is in the field studying how the rodents move in this coffee-growing region in southern Chiapas state, close to the border with Guatemala. Specifically, she’s interested in whether the coffee fields inhibit or help the migration of the animals. She’s wondering if the mice living in the fields are different from the ones in the forest.

Most of the tropical rain forests across the world are fragmented, with patches of forest separated by farm fields. This poses a serious problem for organisms because moving across farm fields – especially those with pesticides – can be challenging for them. If the migration stops, species can experience inbreeding and eventually become extinct.

Read the full Global Michigan story and watch a video featuring EEB graduate students Otero-Jimenez, Senay Yitbarek, Zach Hajian-Forooshani and Ivan Monagan.