In the ancient dinosaur era, amphibians such as frogs once lived in this world with dinosaurs. They were luckier than dinosaurs. They survived and evolved various survival skills. Although they are trying to adapt to the great changes in the world, they are extremely sensitive to the changes around them. Every amphibian is evolving in its own way, and they have evolved a unique attractive appearance and unique survival skills. For example, some have evolved into highly toxic killers, and their venom is enough to kill 100 people; Mexican salamanders never grow up.
Most amphibians will have great changes in their body shape during their lifetime. For example, from the tadpole period, frogs have completely different body shapes and sizes at different stages of their lives. In addition, amphibians are semi-aquatic animals, and their permeable skin must always be moist. They are very afraid of losing water, so the slightest change in some species, habitats or local climate can be fatal.
At present, the species and quantity of frogs in the world are decreasing, and some local species have even become extinct. In many places, the decline rate of frog species and numbers is increasing every year. Scientists know the importance of frogs to the earth. In order to protect amphibians such as frogs and prevent them from extinction, a lot of manpower and material resources have been invested worldwide, such as increasing protection and artificial reproduction. However, it is not easy to raise public awareness of frog protection. Compared with other more endangered species, amphibians such as frogs do not attract the attention of ordinary people. Fortunately, many animal protection organizations actively advocate the protection of frogs, such as the Ugly Animal Appreciation Association.
There are many reasons for the decline of frog species and numbers. At present, amphibians on the earth are facing various survival threats, such as disease, trade, species invasion, habitat destruction, pollution and climate change.
1. Disease
For frogs, pitcher plant disease is a devastating disease, which will lead to the extinction of all amphibians on the earth. This is a fatal skin disease caused by chytrid fungus, and one of the main reasons for its widespread spread is the global transportation of infected amphibians. A recent study shows that since the discovery of chytrid, chytrid has been found in 520 species of amphibians in 56 countries. At present, there are chytrids on all continents except Antarctica. It has caused the number of at least 200 amphibians to drop sharply or become extinct completely.
trade
Global trade also poses a great threat to the long-term survival of amphibians. People buy and sell frogs for pet keeping, scientific dissection, as bait and even cooking food. At the same time, global trade has also caused the widespread spread of pitcher plant diseases.
3. Species invasion
When frogs are transported to a new place, they may be released intentionally or unintentionally. These species began to adapt to the new environment and thrive. They will prey on other local species, destroy the local food chain and spread infected germs. A famous case happened in 1935. At that time, sugarcane toads, native to Central and South America, were introduced to Australia to deal with pests in the fields. However, due to the absence of natural enemies, sugarcane toads are rampant in Australia, and their venom even killed many local animals that used to feed on frogs. Therefore, sugarcane toads have finally become a major public hazard in the local area, and people have to take turns to deal with them.
4. Habitat destruction
Habitat destruction is one of the biggest threats to the decline of amphibian population. The large-scale development of human beings not only transformed nature, but also destroyed it, such as building houses, building roads, logging, damming and opening rivers, which seriously damaged the natural habitat of amphibians. In Britain, thousands of toads die every year on their way back to their habitat after hibernation.
5. Pollution
Amphibians have strong permeability and skin absorption, and are vulnerable to pollutants and pesticides. Pesticides used to protect crops, their chemical components will penetrate into rivers, polluting water quality and food eaten by amphibians. In addition, pesticides will destroy the natural protective layer of frogs, making them more susceptible to infection.
6. Climate change
Amphibians need a humid climate for reproduction, so they are extremely sensitive to climate change in their habitats. Frogs in mountainous areas are seriously threatened by climate warming. In tropical mountainous areas, many amphibians live in cloud forests. Global warming causes clouds to rise. If the clouds rise a few hundred meters, the amphibian habitat will be exposed to the sun, and many frogs living on the top of the mountain will not survive. In addition, scientists also found that the climate change in the rainforest also provided a more ideal environment for the survival of chytrid.
The above threats will make you seem to see the scene before the extinction of dinosaurs. The extinction of amphibian species will also be a great disaster. They are extremely important to our human health, environment and culture. The first is health. About 60% of the Nobel Prize in Physiology or Medicine is about experiments and research on frogs. Secondly, amphibians such as environment and frogs can provide food sources for almost all carnivores; Tadpoles can eat algae, thus making the river cleaner.
(Compile: Binbin)