Buzz
The mother duck swims ahead, and the ducklings follow behind, forming a neat straight line. This is not random; it's the coordinated swimming formation of ducks.
Professor Frank Fish, true to his name, has a profound love for fish and the ocean. Additionally, he is fascinated by ducks swimming on water.
As a professor of biology, his research mainly focuses on the biomechanics of animals. In 1994, Professor Frank published a paper on the swimming behavior of ducks, studying the energy expenditure when swimming in groups.
However, research on duck swimming behavior didn't end there. In 2021, the research team led by Chinese professor Nguyen Chi Minh published a new thesis on duck swimming. Both studies won the Ig Nobel Prize in Physics.
The Ig Nobel Prize, a parody of the Nobel Prize, is awarded annually in early autumn - close to the time when the Nobel Prize is officially announced - for 10 achievements that 'first make people laugh, then make them think.' Its main purpose is to create a cheerful atmosphere to encourage research.
What makes duck swimming so captivating that it fascinates many researchers?
Ducks ride the waves and breeze as they swim
Those who have observed ducks swimming have likely seen the mother duck swimming ahead, followed by the ducklings in a neat single file line. This is not random; it's the coordinated swimming formation of ducks.
The reason why ducks prefer swimming in formation is still under research. However, the benefits of swimming in this formation are gradually being discovered. It's all about saving energy.
In an experiment, researchers calculated the metabolic rate by measuring the amount of oxygen consumed by the ducklings.
During the research process, Frank trained several one-day-old ducklings to swim in a line behind a female duck. Next, the research team conducted experiments on the growth of the ducklings on the 3rd, 7th, and 14th days.
In the metabolic exchange measurement results of the ducklings, the activity frequency increased while the energy consumption of each duckling decreased. This experiment has demonstrated the accuracy of the cause behind the ducklings swimming in formation from a metabolic exchange perspective.
And the underlying cause of this 'energy saving' is waves.
Professor Nguyen Chi Minh's research team focused on observing duck swimming behavior for 7 years, concurrently establishing a correlational mathematical model, uncovering the secret of wave oscillations during duck swimming.
The force diagram of a duck on calm water, with the same wave but different phase. (The green line represents the water surface, the blue curve represents the pressure directed towards the duck's body surface, the arrows indicate the direction of force).
In the 'single-file formation,' when the duckling is in the most suitable position behind the mother duck, the wave resistance at this moment becomes 'positive' - the direction of resistance aligns with the swimming direction of the duckling. At this point, the wave phase is shown in figure (d) above.
In other words, the resistance at this moment turns into a pushing force from behind, propelling the duckling to 'ride the waves and breeze,' helping them swim smoothly. More subtly, this situation can be maintained by the ducklings in formation. The first and second ducklings behind the mother duck are both pushed forward so they can swim ahead with less effort. From the third duckling onwards, the force acting on each individual will gradually approach 0, thus achieving a dynamic equilibrium state.
From this, it can be seen that the leading duck's swimming has helped the members behind expend less energy. This 'wave-riding and wave-passing' mechanism helps the smaller ducks swim behind the larger duck without getting exhausted or obstructed.
Ducks save energy, boats save fuel
Not only ducks but also boats 'swim' in the water. Because ducks are already very intelligent in their movement behaviors, it's natural that humans can't lag behind.
A research team from Wuhan University of Technology analyzed the configurations of different ship formations and found that the overall resistance coefficient of ships moving in a 'stringed' pattern had been effectively reduced. This means that this movement pattern helps ships save energy.
Thinking a bit further, could this principle be applied to all ships in the future? Professor Nguyen Chi Minh's team is exploring related concepts, hoping to bring significant advancements to the maritime transport industry.
Source: Thepaper
