Squirrel Sorters

In the first experiment, the team labeled almonds, hazelnuts, pecans, and walnuts. Then they gave each type of nut to 45 squirrels. They tracked each squirrel using a handheld GPS tracker. When a squirrel buried the nuts for a future snack, the scientists noted the location and timed how long the squirrels took to make a decision.

Back in the lab, the team mapped the results. They found that squirrels bury nuts in different places depending on type and size. Delgado thinks this might help the squirrels remember where the nuts are so they can find their snacks later.

“Like us, animals have to solve problems,” she says. And “those problems are really dependent on the environment that animal lives in.”

Squirrels must bury thousands of nuts each year to eat in winter and early spring, when food is scarce. They also need to remember where to recover their food and keep other animals from stealing it.

First the team labeled almonds, hazelnuts, pecans, and walnuts. They gave each type of nut to 45 squirrels. They tracked each squirrel using a handheld GPS tracker. When a squirrel buried nuts, the scientists wrote down the location. They also timed how long it took the squirrels to choose a spot.

Back in the lab, the team mapped the results. They found that squirrels choose different burial spots depending on the type and size of nut. Delgado thinks this might help squirrels remember where the nuts are. “Like us, animals have to solve problems,” she says. “Those problems are really dependent on the environment that animal lives in.”

Squirrels must bury thousands of nuts each year. They eat them in winter and early spring, when less food is available. The squirrels need to remember where they stashed their food so they can eat it. They also have to keep other animals from stealing it.

Delgado grew to love squirrels through her research. Her favorite was a mother squirrel that the researchers nicknamed Flame. Her bold personality made her a great subject for their experiment, Delgado says.

Urban wildlife is a window into the natural world, and Delgado encourages everyone to take notice. “Studying animal behavior can be challenging. You have to be patient. Animal subjects might not want to participate in your experiment. But my job is also fun and interesting. Animals around us do so many cool things that we don’t realize,” she says.

Delgado grew to love squirrels while she studied them. Her favorite was a mother squirrel nicknamed Flame. Flame’s bold personality made her a great squirrel to watch, says Delgado.

Delgado thinks everyone should pay attention to wildlife, even in cities. It’s a way of connecting with nature. “Studying animal behavior can be challenging. You have to be patient,” she says. “But my job is also fun and interesting. Animals around us do so many cool things that we don’t realize.”