Wild grey squirrels choose better food despite greater effort

The most rewarding choices are not always the easiest ones. New research into squirrels suggests that animals often make smart decisions when they must weigh up effort, time and risk.

Scientists at the University of Exeter studied wild grey squirrels to see how they chose between easier options and better ones.

Their findings suggest that squirrels do not invariably take the easy route. Many opt for higher-quality food, even when getting it demands more effort.

Understanding animal decisions

In laboratory studies, animals often avoid doing extra work. When offered a choice, they frequently select food that is easy to reach, even when a better option is available.

Researchers call this “discounting”: a reward becomes less valuable when obtaining it requires more time or energy. Life outside the laboratory, however, is very different. Wild animals must deal with changing circumstances, competition and risk.

The Exeter team thought that wild animals might make more flexible, practical choices than those observed in laboratory tests.

Testing squirrels’ food choices

The researchers set up a straightforward experiment on campus. Squirrels were offered a choice between almonds, their preferred food, and pumpkin seeds, which they liked less.

The almonds were put on taller poles that were harder to climb, while the pumpkin seeds were placed on shorter, more accessible poles.

Before the experiment, the scientists established that the squirrels had a strong preference for almonds: when both foods were equally accessible, they chose almonds most of the time.

The poles varied in height. As the almond pole grew taller, the squirrels had to climb further and use more energy. The arrangement enabled researchers to assess how much work they would put in for better food.

Squirrels prefer better food

The findings were clear: squirrels kept choosing almonds even as the climb became more difficult. Their preference declined only slightly when more effort was required.

This suggests that squirrels do not readily abandon a better reward. Rather, they will work harder when the prize justifies the effort.

“The squirrels in our study were willing to work harder for the better food,” said lead author Yavanna Burnham.

“This suggests that – in natural decision-making scenarios – it may sometimes be beneficial for animals to wait or work harder for a better outcome. This is what we would expect to find, and it shows the value of doing research on wild animal populations.”

Why effort did not stop them

Squirrels naturally store food and make numerous choices each day about what to eat and what to save. Selecting better food can benefit them over the longer term, particularly when supplies become scarce.

The experiment also let the squirrels move between the two options. In contrast to laboratory tests, the alternative remained available after a choice had been made. This created a more realistic situation and eased the pressure to decide quickly.

Researchers confirmed, too, that taller poles made climbing more demanding. Squirrels climbed them more slowly, indicating that the task took greater effort.

Despite the extra difficulty, many still opted for the better reward.

The role of social life

A squirrel’s social status influenced its choices. Less dominant individuals often selected the food that was easier to reach.

While climbing, these squirrels faced a greater risk of stronger animals taking their food. If another squirrel arrived, a weaker one might lose the reward after putting in all the effort.

“This study helps us understand how animals decide how much time and effort to invest. It shows there isn’t always an ‘optimal’ decision, and – just as with humans – an animal’s social status affects the costs and benefits of particular choices,” said senior author Dr Lisa Leaver.

“It’s rational for different squirrels to assess the situation and adjust the amount of time and energy they will expend accordingly, in order to get a reward.”

Competition also changed behaviour

Other squirrels’ presence affected choices in interesting ways. When they were alone, squirrels often selected the easier option more quickly.

When other squirrels were close by, however, many went for the better reward first. Competition may create a greater sense of urgency, prompting them to act quickly to secure the best food.

The squirrels also avoided risky confrontations. Rather than fighting over food, many picked safer options. This suggests that animals consider risk alongside effort when deciding what to do.

The role of energy levels

Energy levels mattered too. Squirrels that had already made many choices during the day often began selecting easier options later on.

Tiredness, rather than hunger, may explain this shift. After climbing repeatedly, squirrels may steer clear of harder tasks to conserve energy.

The findings indicate that decisions can change over time. Animals alter their behaviour according to how much effort they have already expended.

A simple lesson from squirrels

Funded by the Natural Environment Research Council, the study suggests that animal decision-making is more complicated than straightforward laboratory results might indicate.

When choosing, wild squirrels weigh effort and reward against risk and social factors.

The findings also underline the value of studying animals in natural settings. Real-world conditions provide a clearer view of how they make decisions.

Squirrels demonstrate that a smart choice depends on the circumstances. Extra effort can sometimes bring a better result; at other times, the easier route makes more sense.