If you’ve ever put out a bird feeder, you may have had a few unwanted visitors.
Squirrels can navigate the wild just as dexterously as urban environments—
landing impressive jumps as they leap between trees.
But moving through the canopy isn’t as easy as it looks.
Branches bend and curve in a variety of ways.
This impacts how squirrels generate momentum, especially for long distance jumps.
New research lays out how quick decisions allow squirrels to traverse tree canopies
and perfect their landings.
The scientists’ daredevil of choice was the fox squirrel, found throughout North America.
In order to best observe their acrobatic capabilities, researchers brought the lab to the squirrels.
To lure them to participate, researchers rewarded them with an irresistible treat
after they completed a jump: shelled, unsalted peanuts.
This is how they trained them to jump from point A to point B.
First, researchers created “branches” with different levels of bendiness
and observed how squirrels leapt off these structures.
Squirrels launched farther from the branch attachment when the beam was rigid.
In comparison, squirrels leapt sooner off bendier beams, traveling distances more
than three times their body length.
After modeling the data, scientists found that the flex of the beam played a large role
in where squirrels decide to launch from
even more than the distance of the landing perch.
Next, they presented the squirrels with a different set-up: a launching point with almost
three times greater give, and nearly double the distance of previous tests.
They trained the squirrels to attempt the same type of jump multiple times.
Although they landed every attempt, the squirrels reduced their landing error over time.
For their final experiment, researchers increased the gap distance,
and changed the height of the landing perch.
The squirrels rose to the challenge yet again, but with an unexpected move:
bouncing off the vertical board the perches were attached to.
Scientists think the added contact mid-leap helped the squirrels calibrate how fast they land.
This study shows that squirrels think fast on their feet, using what they’ve learned
from previous jumps to make their next landings stick.
In the future, researchers hope to use this data to build a robot that’s just as agile
for search and rescue missions.
To humans, that’s worth a lot more than a claw full of acorns.