Guangdong Luokeng Crocodile Lizard Nature Reserve, located in Qujiang District, Shaoguan City, Guangdong Province, the reserve has a complex interior, surrounded by mountains, dense forests, many strange vines and trees, canyons and streams can be seen everywhere. In the streams and ditches under the forest, there is a creature of the dinosaur era, that is, the crocodile lizard.
This animal has a head like a lizard and a tail like a crocodile, hence the name crocodile lizard, which is a national first-class protected animal. Because the crocodile lizard will dive into the water when frightened, the locals call it a falling dog and a diving dog; in Jinxiu, Guangxi, because the crocodile lizard snoozes and likes to be quiet, it is called a big sleeping snake and a wooden sleeping fish; in Guangdong, because the crocodile lizard has colorful skin and five fingers, it is called a five-clawed golden dragon. The nickname of the crocodile lizard is both interesting and domineering, so let's call it a falling dog!
The falling water dog was first born 200 million years ago, and their ancestors lived in the same era as dinosaurs, and they were once neighbors. Powerful dinosaurs became extinct in the late Cretaceous period, while tiny falling dogs survived, the primitive reptiles left over from the end of the Quaternary glaciation period, and continue to this day.
Between 1928 and 1929, a team from the Department of Biology of Sun Yat-sen University went to Dayao Mountain in Guangxi Province and found 28 reptiles with lizards with heads and crocodiles on their tails. Later, this peculiar reptile was named the crocodile lizard by experts. Because it was first found in the Great Yao Mountain, it is also called the Yao Mountain Crocodile Lizard.
Before the 21st century, crocodile lizards have been considered to be distributed only in Guangxi, in 2001, amphibian and reptile expert Professor Li Zhenchang came to Guangdong Luokeng to investigate, found that the "five-clawed golden dragon" is a crocodile lizard!
The falling water dog is known as the "living fossil" of the primitive lizard, the "giant panda" of the reptile world, and retains the ancient pedigree of reptiles, which has very important scientific research value.
However, the number of falling water dogs has not been large, and the number in the wild is only about 1400, making it a critically endangered species. The distribution of falling water dogs is also very narrow, mainly distributed in Luokeng and Maoming in Guangdong, and Hezhou and Jinxiu in Guangxi. It is also found in northern Vietnam.
Curious what a falling dog looks like? Adult drowning dogs weigh about 100 grams, have a head like a lizard, a cylindrical body, and a body length of generally no more than 40 cm; the tail is shaped like a Yangtze crocodile, and the tail length is more than half the body length.
Curiously, each falling dog's tail has ridge-like scales, and many black broad horizontal stripes, and each tail stripe is distinctive, just like a human fingerprint, unique.
When a drowning dog encounters danger, it will automatically break its tail to survive, and then grow a new tail. If you look closely, you can also distinguish the newly grown tail, and the pattern is different from the original pattern.
The falling water dog has a well-developed eyelid, an oval pupil, and a "three eyes". Its head is slightly tapered in a four-sided shape, and the top of its head is balanced and covered with fine scales. There is a distinctly milky white dot in the center of the top of the skull called the cranioceploe, which is its "third eye".
Look again at the skin of the drowning dog, which is covered with fine, granular scales. Adult drowning dogs, females and males have obvious differences, the male cephalothorax ventral surface is bright red or light blue, colorful, more beautiful, while females are light yellow or reddish.
The falling water dog prefers to inhabit the mountain rush creek ditch below 750 meters above sea level, the water quality is clear, under the lush broad-leaved forest, overgrown, wet and shady place, the most likely to see the trail of the falling water dog.
Usually, the falling water dog will find a comfortable trunk, hold the trunk to rest, and stay motionless for half a day. Sometimes they would hide in the water, their heads sticking against the stone walls to expose them. Locals say that the falling water dog sees people and dives into the water, so it is called the falling water dog.
When the falling dog sleeps with a branch in its arms, you gently touch its back, it will not respond, but if you touch the branch, it will immediately turn over and jump into the water to hide in the stone cave, diving for up to 20 minutes.
Falling water dogs generally feed in the morning and dusk, and earthworms, spiders, small frogs, fish, and various insects can become food for falling water dogs.
When preying, the falling water dog brakes with a static brake, lying still on its stomach, and when it finds its prey, it jumps down to prey on it, and swallows the earthworm with its mouth open. Sometimes peers will tear each other apart for food.
The falling dog has no fighting power, and in the forest, even snakes and birds will become its natural enemies. When encountering enemy damage, he also used static braking to try to pretend to be dead to escape the disaster. When the enemy is relaxed, jump into the water and hide.
If the situation is really critical, when the small tail is grabbed by the predator, the falling water dog will choose to break the tail to survive. It doesn't matter, save your life first, and the tail can grow again.
From June to mid-September, it is a large number of hunting seasons for falling dogs, and in the autumn of October, the weather turns cooler, and the appetite of the falling water dogs will also decrease, and the temperature will begin to hibernate when it drops to 15 ° C.
According to researchers, there are two forms of hibernation of falling dogs, one is in a stone cave, and the other is in a tree cave and a sand nest.
Hibernation is different from the usual state of false sleep, with closed eyes, sagging head, and lying still in the nest without eating or moving. The state of sleep is also affected by the temperature, when the temperature is 15-17 ° C, it is the early stage of stinging, when it is affected by external interference, there will be a reaction; when the temperature is 10-12 ° C, it is a lethargic period, the body is stiff, even if you touch it with your hand, it has no response.
Because of the abundant summer food, when it first entered hibernation, the falling water dog was still relatively fat. After entering hibernation, the metabolic rate decreases rapidly, and when the temperature is 8-10 ° C, there is no breathing action for a long time, and the oxygen consumption is 1/5 of the active period. After hibernation, the weight will be lost about 10 grams.
The dog slept for 5 months, and did not wake up until March of the following year and began to move out of the nest. Falling water dogs are really special snoozing, no wonder it is called the big sleeping snake.
Every year from May to August, the falling water dog enters the breeding period, and the male will shake his head up and down in front of the female, showing off himself. Female falling dogs will choose males with brighter colors and stronger bodies.
For courtship, males also compete with each other, fighting each other, biting each other, and the winning party has the right to mate. The winning male falling dog will directly express his love in front of the female.
The male falling dog, who could not find a target, had to beat a single stick and courted again next year. After all, the population is sparse, narrowly distributed and dispersed, and it is impossible to "marry distant relatives".
After the female drowning dog becomes pregnant, the male will leave and may go to find another object. The female drowning dog was pregnant alone in October and did not give birth until May of the following year.
The drowning dog is an oviparous fetus, which exists in the form of an egg in the mother's body, and hatches in the mother's body, and after birth, it is a freely moving pups. On land or in the water, litters can be born. As soon as the pups are born, they can live independently, and they are born to hunt and feed themselves, without the need for parents to raise them.
The drowning dog, which was born not long ago, looks very similar to an adult individual, but the skin is relatively dark, and there is a small macular "birthmark" on the top of the head, which will disappear after 3 months.
The falling water dog is a little elf in the mountains, snoozing is not moving, and hibernating is nearly half a year. Less activity and lower needs for food and energy may be the way for drowning dogs to survive.
Xuelinggu Nature Lab/Production
References: China National Geographic, Science China, Forest and Humanity, China Green Times, Hezhou Daily, Science and Technology Daily