100,000 Why: Why do frogs bark when it rains?
The reason why frogs croak when it rains
Every rainy day, frogs make special noises. Especially when it's about to rain, the frogs' cries are one after another, getting louder and louder, which really seems like a concert.
Frogs don't like living in an environment that is too cold, too hot or too dry. They like cool and humid places, so when it rains, they are really happy for frogs. Especially after a sunny and dry day, when it is about to rain, because the air pressure drops, the humidity increases and the water in the air increases, the frog's skin is fully moist, so it becomes active.
At the same time, in the rainy season, many insects breed at this time, and these insects are the food of frogs. At this time, the frog has just passed the cold and dry winter and needs a lot of insects to recover its strength. With good food and a good environment, frogs can't help singing loudly; Taking this opportunity, male and female frogs also mate and breed near the water in Chi Pan.
Summer nights are very hot. There were waves of frogs' cries in the field: "Quack, quack, quack". This kind of animal chorus often comes and goes, echoing in the night sky all night.
Frogs are amphibians, that is, they can live in water or on land. However, tadpoles that haven't become frogs can't live without water, because they breathe through their gills like fish. After tadpoles grow into frogs, they gradually get used to breathing with their lungs, so that they can live on land.
Although frogs are amphibians, they seem to prefer living in water. We can often see frogs at the water's edge "plop, plop" jumping into the water for a while, and then onto the shore or lotus leaf. At least, frogs like wet environment very much. Therefore, whenever it rains, the humidity in the air becomes higher and higher. At this time, the frogs in the field will cry "happily". When the rain falls, the frogs in the pond jump up and down happily and are busy.
Extended reading:
Frog habitat
Because the skin is exposed, it can't effectively prevent the evaporation of water in the body, so they can't live without water or wet environment for life, and they are afraid of drought and cold. Therefore, most of them live in tropical and temperate rainy areas, and there are very few species distributed in cold zones.
When I was a child, I could only live in water. When I grow up, I can live on land. Frogs breathe with their lungs, but they can also draw oxygen from the air through wet skin. Various pigment cells in its skin will also expand or contract with the change of humidity and temperature, thus changing the depth of skin color. Frogs usually inhabit rice fields, ponds, ditches or grass by the river, sometimes they lurk in the water and usually hunt at night.
The living habits of frogs
singer
There is a bulging thing on the frog's mouth that can make a sound. It likes to sing loudly on rainy days in summer. In hot summer, frogs usually hide in the grass and occasionally make short calls. If there is a cry, the people next to them will scream a few times, as if singing to each other. Frogs are happiest after the heavy rain. At this time, there will be dozens or even hundreds of frogs croaking endlessly, and the sound can be heard for miles away.
Vocal cords are the vocal organs of frogs. Located above hilar cartilage. On both sides of some male frogs' squabbles, there are external sound sacs that can expand and vibrate, and the sound sacs produce * * * sounds, which make the frogs' songs magnificent and loud. When you walk to the pond after the rain, you will hear the cries of male frogs echoing each other, one after another, forming a chorus. Scientists point out that frog chorus is a veritable chorus, which has certain rules, including lead singer, chorus, chorus and accompaniment, and is closely coordinated with each other. It is speculated that chorus is much better than solo because it contains more information. Chorus is loud and far away, which can attract more female frogs, so frogs often use chorus.
Master of physical education
Its eyes are protruding, its head is triangular, and its crawling action is very slow. Maybe you'll think it's a little silly. However, as soon as you get close, you jump into the pond with duckweed. The distance of this jump is 20 times its length. Then, swim to the other side in the most standard breaststroke posture.
Frogs don't jump the best in the world like copepods, but their jumping ability is also excellent. In the frog family, some smaller members can jump 10 times their length. According to a recent study published in Journal of the Royal Society B, the secret of frog's powerful jumping ability lies in its leg muscles, which are far more flexible than mammals. Before jumping, frogs will squat down to stretch their hind leg muscles and challenge the laws of physics. This kind of stretching can make frogs produce incredible mechanical energy and strength, and finally get rid of the potential threat with an amazing leap.
The Great Impostor
This frog has a white belly, a yellow-green head and back, and some dark brown stripes. Some have three white marks on their backs. The reason why frogs are green is a good disguise. It is almost the same color as the grass in the grass and can protect itself from the enemy. Frog's head has two round and prominent eyes, a wide and big mouth and a long tongue. The back of the body is green with dark stripes and the abdomen is white. There are four legs under the body, the front leg is short, the back leg is long, and there is webbed toes. Frogs are amphibians. They can jump on the ground and swim in the water. They will make a "croak" sound, and the male will cry loudly.
In spring, frogs lay eggs on aquatic plants, and the eggs gradually become tadpoles. Tadpoles are black, round and have a long tail. Tadpoles grow up day by day, first the hind legs, then the front legs, and the tail gradually shortens and degenerates, and finally becomes a frog. Frogs are experts in catching pests. Frog catches pests with its long and wide tongue. The root of the tongue grows in front of the mouth, and the tip of the tongue branches backwards, with a lot of mucus on it. As long as a small flying insect flies by, it will suddenly jump up, open its mouth, quickly stick out its long tongue and eat the pests at once. Frog's eyes are slow to see still things, but keen to see moving things.
Natural Selection, survival of the fittest.
Predation between organisms, natural selection; Can survive with the change of environment.
There are many kinds of pigment cells on frog skin: melanocytes with black or brown pigment particles, yellow pigment cells with yellow pigment particles, red pigment cells with red pigment particles, and many iridescent pigment cells with reflective crystal plates.
The skin consists of epidermis and dermis. There are various pigment cells in the dermis, but there are only smaller melanocytes in the epidermis. Because the epidermis is thin, the color inside the dermis can be revealed. When the frog is in a dark environment, the environmental phenomena perceived by the eyes are transmitted to the pituitary gland in the middle through nerves, so that it secretes melanin, promotes the diffusion of melanin, and contracts red pigment and yellow pigment. In this way, the red and yellow pigments retreated, but the melanin was very obvious, and the frog was dark. The change of body color is mainly the result of the participation of larger melanocytes in dermis.
Environmental temperature and adrenaline can also cause frogs to change "fashion". As the temperature rises, the color becomes lighter; As the temperature decreases, the color becomes darker. At the same time, the body color is lighter and the heat absorption is less; Dark body color absorbs more heat, which is beneficial to the regulation of their body temperature. If the frog is injected with adrenaline, its body color will become lighter with the increase of blood pressure.