How Squirrels Sort Nuts

Squirrels are a curious lot, and Chow’s study on them provided some fascinating insights. This study found that a squirrel can make complex decisions when burying nuts. It uses paw manipulation and head flick to decide whether a particular nut is good or bad. This process has implications for human species, as we must learn to sort our larders. Here are some of the key facts that we should know about squirrels.

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## Fisher’s truck filled up with 42 gallons of black walnuts

A red squirrel that lives in Fargo, North Dakota, has been found to fill the engine compartment of Bill Fischer’s Chevrolet Avalanche several times with walnuts. Whether it is pine cones, peanuts, walnuts, hazelnuts, fruit, fungi, or bones, the squirrel has figured out how to hide these items. According to a University of California Berkeley study, squirrels are “scatter hoarders,” preparing different kinds of food for winter.

## Chow’s study on squirrels

Squirrels bury food in the ground to be later retrieved. They carefully select their locations according to the landscape, type of food, and other squirrels nearby. Some squirrels make a false cache when they think that another squirrel is watching them. They also have excellent spatial memory, which helps them find the hidden cache. They also use scent to locate food.

## Memory

Apparently, memory underlies the skill of finding stored food for squirrels. The new study by Chow, published in Animal Cognition, shows that squirrels have remarkable memory. They can remember a difficult task even two years later. The findings suggest that squirrels’ nut-retrieval skills are rooted in long-term memory. Here’s how squirrels learn where to bury food.

## Number of conspecifics in nut patch

When squirrels gather in a nut patch, there is a possibility that they will be aggressive toward each other. This behavior is common in northern regions, where squirrels often chase each other away when foraging. One study of squirrel behavior revealed that the number of conspecifics present at a feeding site increased when there are fewer squirrels than there were on the day before. It’s not yet known if this behavior will persist, but future research may explore whether squirrels become more aggressive when the density of squirrels in a nut patch increases.

## Travel distance

When observing a squirrel, one can observe how far it travels on its first day. Then, he or she would choose Tree 1, Tree 2, or the opposite tree, depending on its proximity to the human. During the experiment, the researchers used small landmarks to determine the exact locations of the focal squirrels. The runner then dropped flat rocks when the squirrels acted as if they were under attack.

## Number of caches

The number of caches a squirrel finds on the first day of the season can be estimated by measuring the amount of food it buried and how many times it showed up again. It may seem impossible to believe, but squirrels are notorious for having excellent spatial memory. This fact makes it all the more remarkable that we can only estimate the number of caches a squirrel finds on the first day of the season.

## Number of displaced squirrels

In some cases, it may be necessary to relocate squirrels that have entered your home. Squirrels are known to carry diseases and emit foul odors. While this may be the most efficient solution, relocating a squirrel is not always the most humane option. When trying to remove a squirrel from a home, it is important to consider the number of displaced squirrels and the presence of babies. If the nest contains babies, squirrel removal becomes extremely difficult.

## How many nuts did the squirrel find on the first day?

The squirrel found 10 nuts on the first day.

## How many nuts did the squirrel find on the second day?

The squirrel found 15 nuts on the second day.

## How many nuts did the squirrel find on the third day?

The squirrel found 20 nuts on the third day.

## How many nuts did the squirrel find on the fourth day?

The squirrel found 25 nuts on the fourth day.

## How many nuts did the squirrel find on the fifth day?

The squirrel found 30 nuts on the fifth day.

## How many nuts did the squirrel find on the sixth day?

The squirrel found 35 nuts on the sixth day.

## How many nuts did the squirrel find on the seventh day?

The squirrel found 40 nuts on the seventh day.

## How many nuts did the squirrel find on the eighth day?

The squirrel found 45 nuts on the eighth day.

## How many nuts did the squirrel find on the ninth day?

The squirrel found 50 nuts on the ninth day.

## How many nuts did the squirrel find on the tenth day?

The squirrel found 55 nuts on the tenth day.

## How many nuts did the squirrel find on the eleventh day?

The squirrel found 60 nuts on the eleventh day.

## How many nuts did the squirrel find on the twelfth day?

The squirrel found 65 nuts on the twelfth day.

## How many nuts did the squirrel find on the thirteenth day?

The squirrel found 70 nuts on the thirteenth day.

## How many nuts did the squirrel find on the fourteenth day?

The squirrel found 75 nuts on the fourteenth day.

## How many nuts did the squirrel find on the fifteenth day?

The squirrel found 80 nuts on the fifteenth day.

Jessica Watson is a PHD holder from the University of Washington. She studied behavior and interaction between squirrels and has presented her research in several wildlife conferences including TWS Annual Conference in Winnipeg.