A new study from a team of biologists and animal movement experts has revealed that the grounded running style of birds like the emu is more energy-efficient than the ungrounded running style of many other animals, including humans. This fascinating discovery sheds light on the evolutionary advantages of this unique locomotion technique.
The Emu’s Grounded Advantage
They never quickly become airborne when running at medium speeds, according to a study in the journal Science Advances. And they always have one foot solidly planted on the ground.
The researchers found that this grounded form of running consumes less energy than the leaping form, where runners both push away from the ground and upward against gravity with each step. To test this surprising result, the team created a digital model of an emu’s musculoskeletal system to simulate its running mechanics.
The researchers say being forced to crouch is why an emu — whose anatomy has evolved around this characteristic — cannot extend its legs all the way. This anatomical constraint probably informs much of the way the emu ran that you saw because it would be more energetically expensive for an intermediate-speed running EMU to run with an ungrounded style.
Takeaways from the Lesser Dinosaurs
The grounded running style of birds is thought to have evolved from the way non-avian dinosaurs ran, and their anatomies are similar so they would be expected to run similarly.
This finding has huge potential consequences for what we know of dinosaur movement and avian flight evolution. Research about the running styles of present-day birds that naturally can run long distances without investing energy [Jones] may ask us what motion patterns and adaptations of an African terror bird are required to get it moving effectively down a gravel asphalt.
It also moved in a very similar way to a real-life emu, the researchers explain, thereby confirming their results even further. It illustrates how the application of digital simulations to real-world observations can be very powerful in revealing some of the secrets behind animal locomotion.
Conclusion
These results question our assumptions of the most cost-effective casual bipedal walking and highlight that there may be many advantages to using a grounded running model, similar to the locomotor style used by ratite birds such as the emu, to inform improvements in human mobility, especially energy consumption. The more we learn about the ancient past of these fascinating animals, there may be an untapped well for how it can positively impact our movement and technological development.
