The term "bird brain" should be dismissed: studies reveal that emus are significantly smarter than previously believed.

Over the decades, the term "bird brain" has become incredibly popular and quite insulting. However, studies have already shown that Eurasian jays can pass the marshmallow test, some species possess a "culture," and even extinct species like the dodo were likely much smarter than previously thought, writes Popular Science.

For years, large birds known as paleognaths—the closest relatives of dinosaurs—have been considered simpler creatures. But now, new research indicates that some large birds appear to be significantly more intelligent than previously believed. Scientists found that these birds are capable of solving physical challenges to access food.

Emus and ostriches, which can reach nearly 3 meters in height and weigh over 130 kg, are classified as paleognaths. Typically, these birds are better known for their muscles than their brains; they often rely on running speed and powerful kicks for self-defense. This has led to emus being labeled "the dumbest birds in the world" for decades.

According to co-author of the study and comparative experimental psychologist at the University of Bristol in the UK, Fei Clarke, the more scientists study the same species repeatedly, the more they learn. At the same time, a false impression is created that other species are "less intelligent," when in fact they simply haven't been studied to the same degree.

For the new study, the team examined three species of paleognaths at the Bristol Zoo: emus, rheas, and ostriches. The researchers developed a test to measure the paleognaths' capacity for innovation, defined as "using existing behaviors in new circumstances or inventing entirely new behaviors." Testing innovation and its connection to animal cognition is a common method for scientists to gauge overall intelligence.

The new test was based on previous conditions and involved a rotating wheel that had to be moved in the right direction to align with an opening for a food reward. The results showed that each of the three species completed the test in 10 sessions.

Emus were able to align the hole with the food chamber and move the opening in the most efficient direction toward the food 90% of the time. A male rhea employed the same technique but also devised a second method. He spun the wheel from the middle until it broke apart. However, this particular group of ostriches did not exhibit any innovations during these tests.

According to Clarke, she and her colleagues classified the innovations of paleognaths as low-level or simplified—that is, not as complex as the innovations observed in crows and parrots. Still, the team believes their discovery is incredibly significant.

Prior to this research, scientists had no reports of technical innovations among paleognaths, leading them to consider these birds not very clever. The results of the new study indicate that this is not true: technical innovations may have developed in birds much earlier than previously thought.