In front of the narrow hole, Bi Fang identified the animal tracks that passed by.

Some of these footprints have survived quite a long time.

The dry-season African savannah has a hard and dry surface, leaving few footprints, except for giant reptiles like the Komodo dragon, whose sharp claws leave a row of small holes in the hard ground due to their massive body weight.

Most of what everyone saw at the entrance of the cave was left behind by the wet season.

However, there are fresh footprints, paw prints, and hoof prints in the cave.

"There are no large carnivores."

After watching it for a long time, Bi Fang confirmed the matter.

Then he checked his surroundings and confirmed that there was only one entrance to this underground river within a certain range, so he took Halley to hide behind a pile of rocks, ready to wait for the rabbit.

Sticking to the stone, Bi Fang sat on the ground, polishing his spear.

"The quality of human life has improved dramatically in recent decades – the tall buildings, the bustling streets, the beautiful night scenes, these are no longer new."

"The rapid development of technology has made our lifestyle more and more sophisticated, and what used to be considered a luxury is now easily achievable."

"In terms of three meals a day, we are no longer just pursuing a satisfying stomach, but have higher quality requirements for taste, and we are pursuing "food"."

"However, for the wild animals that also inhabit the planet, filling their stomachs is still their primary problem."

"Herbivores or omnivores are optimistic, food sources are relatively abundant, as long as they are not born in deserts, places like the Gobi Desert, there is always something to eat."

"The requirements for carnivores are higher, and they have to hunt for food."

"In the process of hunting, the predator needs to fight with the prey, which is a double test of energy and physical strength, and even if the hunt is successful, the food obtained cannot be stored for a long time, and there is even a risk of being snatched."

Bi Fang put the polished spear on his back, and then looked for some plants with a strong smell nearby to hide his figure.

Perhaps because of their proximity to the water source, the plants that grow in the crevices of the rocks are green, much more vibrant than the bright yellow hay seen in the grasslands.

"One of the main tasks of our visit to the African savannah this time is to let Halley learn to hunt, so that he will not be stupid and unable to eat meat when he lives alone on the grassland."

"However, different species of predators have different temperaments, tastes and physical conditions, and their predation styles are naturally different, so we also need to demonstrate according to the characteristics of the animals themselves."

"For example, the difference in the predation style of lions, tigers and wolves reflects the difference between cats and canines."

"The lion and tiger are strong and agile, and the latter prefers to be alone. The gray wolf is weaker in size and speed than the lion and tiger, but the social life makes the gray wolf's predation efficiency much improved."

"When the Canadian gray wolf catches bison, it will constantly use trap harassment tactics in the snow-covered natural environment, causing the bison herd to fall into confusion, waiting for an opportunity to attack the lone bison."

"It's rare to be like the Big Big Wolf and want to sweep the sheep village on his own."

"Compared to wolves, tigers are much more arrogant as felines, and even among the lions that hunt in groups, there are many male lions and a few female lions who like to act alone."

"Feline hunting pays attention to ambush, highlighting a fast and ruthless accuracy, even if the cheetah is the king of speed, many times hard pursuit can catch up, but that is actually an additional cost, ambush is the best choice."

"So, the focus of our demonstration is on the ambush."

"No matter what strategy is used, the predation operation needs to have a major premise, that is, it must first be able to find the prey, otherwise no matter how strong the predation ability is, it will be on paper."

"For wild animals, the most natural foraging strategy is to simply follow Brownian motion and fly in the future."

Brownian motion?

Flying to Levy?

When Bi Fang talked about how to find prey, he suddenly heard a physical concept, and many viewers were a little confused.

"That's true, but the main body who looks for traces, traces, and finally discerns direction is me, a human."

"It's too much of a test for animals to have a clear grasp of these things."

"Most of the animals at the top of the food chain, such as lions, tigers, wolves, eagles, crocodiles, etc., rely mainly on sight to find prey."

"There is no gradient difference in visual signals, what is not seen is what is not visible, and no animal has clairvoyance."

"Birds like eagles have a wide field of vision and don't have to fight hard when it comes to foraging, but land animals like lions and tigers have to think about foraging strategies."

"Without knowing the prey apparatus, Brownian exercise is the most natural method."

But before Bi Fang finished explaining, the audience was even more confused.

For a while, the barrage was full of questions or inquiries.

"Well, we don't know much about the world of smell."

Bi Fang scratched his head, after all, the audience did not have the same keen sense of smell as him.

The gap in perception makes everyone seem to be separated by two worlds.

After thinking about it for a while, he came up with an example that he thought was more appropriate.

"Let's put it this way, if you put an alarm clock in the room on the second floor of a villa, and you sit in the living room on the first floor, can you accurately determine which room the alarm clock is on the second floor by simply relying on auditory capture?"

"I think most people can't do it, in the animal world with a keen sense of smell, their sense of smell plays the same role as our sense of hearing at this time, knowing that the prey is on the second floor, but not knowing which room it is in, and the sense of smell is more ambiguous than the sense of hearing."

"Just staying in one place for a long time can create two places with strong smells, which is not possible in the world of sound."

"Everyone should be familiar with Brownian motion, a never-ending irregular motion of particles suspended in a liquid or gas, a continuous random process."

"Brownian motion may seem insignificant, but its discovery is a major development in physics that has had a huge impact on our understanding of the universe."

"The behavior of many creatures in nature also obeys this invisibly, and animals that perform Brownian motion, like coming to the second floor, randomly enter a room to search, and from a data point of view, this is still the most efficient way."

"Its step size obeys a normal distribution, like a random walk, and its step size and direction are discrete. Although Brownian motion and random swimming are two different concepts and have developed different theories, the mathematical essence of the two is the same, and there is practically no difference in the efficiency of finding prey, regardless of the foraging strategy adopted by the predator."

"But if a predator really does Brownian motions aimlessly like a headless fly, can it really be very effective in finding its prey?"

Bi asked the audience questions.

You don't need to answer to know that this answer is no.

"Mathematically, it can be proved that Brownian motion is the same as the free diffusion of molecules, and the average displacement of a molecule per unit velocity in time t is only the root number t."

"If a predator uses this method to find prey, it may take a lot of mountains and rivers to succeed."

"So before that, there is another way to determine which villa the alarm clock is in the community, which is another mathematical concept, to fly in the dimension."

"It was Paul Pierre Levi, the mentor of the French mathematician Benhua Mandelbeau, who discovered that many random motions of life belong to Levi flight, and that there is also a small part of Brownian motion."

"This is a rather complex concept, so I won't explain it too much, but there is an example that you should be familiar with, the flight trajectory of flies, the application of which is to fly in the dimension, this principle makes their flight trajectory elusive, helping flies avoid predators and humans who want to knock their small heads flat.

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"Flying in the dimension is a fractal, which means that no matter how many times you zoom in, it still looks similar to the original figure."

"What's more, Levi's flight is a random walk, which means that its trajectory cannot be accurately predicted, just like the pace of a fly."

"One of the characteristics of Brownian motion is that the step size of each step is concentrated in a single area, which is a bell curve when drawn."

"This is not the case with Levi flight, in the Levi flight chart, the distance traveled per walk conforms to the power law."

"In other words, most of the steps in the sport are short, but a few are very long."

The vast majority of the audience in the live broadcast room were basically stunned when they heard this.

"The different nature of the step size of Levi flight and Brownian motion directly leads to Levi flight being more efficient than Brownian motion."

"With the same number of steps or distances, the flight displacement of Levi is much larger than that of Brownian motion, and it can explore a larger space."

"This is crucial for creatures that need to jungle in uncharted territory."

"For example, marine predators such as sharks use Brownian motion when they know there is food nearby, because Brownian motion helps to 'disc' – to open and empty hidden food in a small area."

"But when food is scarce and new territory needs to be explored, marine predators abandon Brownian motion in favor of the strategy of flying to the next level."

Behind the rocks, Bi Fang and Harley, who was resting again, scanned the surroundings, wondering if any prey was coming.

At the same time, continue to chat with the audience.

"In '08, a team of researchers from the Central and Ugly countries published a study in nature: 55 different marine predators in the Atlantic and Pacific Oceans, including silky sharks, swordfish, blue marlin, yellowfin tuna, sea turtles and penguins, were tracked and tracked over a period of 5,700 days."

"After analyzing 12 million of their movements, it was discovered that most marine predators have a preference for Levi locomotion when food is scarce."

"What's even more interesting is that the distribution of prey, such as krill, also matches the characteristics of Levi's flight."

"Not only that, but the routes of amoebae, plankton, termites, bumblebees, large land herbivores, birds, primates, and indigenous peoples in the soil are similar."

"Flying in Vivi seems to be a common law for living beings to survive in an environment where resources are scarce."

"For animals that wander the world, finding their next meal depends not only on luck, but also on advanced mathematics."

"With little to no knowledge of the distribution of their prey, Levi flies far more efficiently than Brownian motion, which may be why they switch to Levi flight mode when they try their luck."

"Therefore, biologists later proposed the flying foraging hypothesis to summarize the coquettish position of animals when they resigned themselves to their fate."

"However, just because wild animals are left to their fate, doesn't mean that Harley should also be left to fate, we can help him realize that there is a greater probability of encountering prey in some places, and just do Brownian exercises in a few fixed locations to help him survive better on the grassland."

After sitting behind the rocks with Harley for a long time, at noon, Bi Fang met his first real prey on the grassland.

An ostrich!