The existence of living things on earth cannot be separated from natural selection, a selection that determines whether the creature can maintain its kind to live or die in the face of extinction. Living things can defend their existence from extinction by reproducing, but there are also many factors that hinder the rate of reproduction.
Especially animals, not all animals with various types can defend themselves from extinction. In fact, over the last 50 years many animals have had to face extinction. What animals are they?
1. Japanese Sea Lion
The Japanese sea lion or Latin name Zalophus japonicus is a water mammal that has been declared extinct. This statement of the extinction of the sea lion typical of East Asia was put forward in the 1970s.
In fact, at the beginning of the 20th century, the Japanese sea lion population was very abundant and spread across Japan, Korea, and the southeastern Russian region. However, with the excessive exploration of the fishermen, this animal population is shrinking. Until the 1940’s this species was declared nearly extinct.
2. Duck Oustalet
Mariana Mallard or commonly known as oustalet duck is a duck endemic to the Mariana Islands in Pacific waters. Oustalet duck has the Latin name Anas oustaleti.
The oustalet duck was extinct due to uncontrolled hunting in the 20th century and the Mariana Islands which were currently in the battlefield of World War II. In Saipan, one of the areas where oustalet ducks spread, the number of oustalet ducks is decreasing all the time due to water pollution caused by sugar factory waste.
3. Fish Tecopa
Tecopa fish or Tecopa pupfish are fish that can survive in hot water temperatures. This tecopa fish is endemic to the hot springs of the Mojave Desert in California, United States. This fish is small with only about 2.5-4 cm in length. Cyprinodon nevadensis calidae is the Latin name for this tecopa fish.
In the 1950-1960s, hot springs, which are natural hot springs, became very popular in the United States. As many people come to the hot springs as hot springs in Mojave, the tecopa fish habitat is threatened. The tecopa fish population is decreasing all the time.
4. Dusky Beach Sparrows
Until the 1960s, the Dusky Beach sparrow population was scattered on the east coast of Florida and Merrit Island, where there were still many marshes suitable for their habitat. The problem of mosquito breeding and control makes this sparrow habitat disturbed. The excessive use of DTT and pesticides is a threat to this bird population.
It is not enough to stop there, road construction and changes in the function of swamps have eroded the habitat of these birds. In 1987 many of these sparrows were found dead. Until 1990 the Dusky Beach sparrow was declared extinct.
5. Costa Rican Golden Frog
The last golden frog to appear was a male frog that was seen on May 15, 1989. In fact, in 1987, an ecologist and herpetologist, Martha Crump found 133 frogs that were in the breeding season even though a few months later he found thousands of moldy frog eggs. and leaving only 29 tadpoles.
The fast extinction of the golden frog was allegedly due to climate change, where the frogs could not reproduce with such rapid temperature changes. Another cause that led to the extinction of the Costa Rican golden frog was water fungal disease. The chytrid fungus that causes chytridiomycosis contributed to the extinction of this frog.
6. Baiji
Baiji is a freshwater dolphin that can only be found in the Yangtze River, China before it was declared extinct in 2006. Baiji has the Latin name Lipotes vexillife. Baiji is on the IUCN Red List in the critical list and it is possible that this animal has become extinct.
It is estimated that in the 1950s the population of baiji in the Yangtze reached 6,000. The number of baiji is decreasing due to illegal hunting. In 1979 China declared that baiji was threatened with extinction, so in 1983 it was declared that hunting baiji was illegal.
7.The Pipistrelle Christmas Island bat
The Christmas Island pipistrelle bat is a type of bat from Christmas Island (an island which is part of Australia and is located south of Java). The bat, which has the Latin name Pipistrellus murrayi, was last seen in August 2009 and has never been seen again.
During the last decades, these bats can easily be found on Christmas Island. In 2006 there has been a decrease in the number of this bat population by 90% (according to IUCN data) and only 4 left in January 2009.
The cause of the extinction of these animals is not clear. According to an IUCN (International Union for Conservation of Nature) release, the cause of this bat extinction could be due to the impact of the large number of yellow ants invading their habitat and prey, or the impact of an unknown disease, but the causes have not been proven.
8. West African Black Rhino
The West African black rhino was declared extinct by the IUCN Red List in 2011. In fact, in 2006, the existence of the West African black rhino could no longer be found. Researchers at that time found no evidence of rhino life, such as droppings or food scraps, but they did find evidence of widespread poaching that is responsible for the loss of rhinos in the wild.
In the 1900s, the West African black rhino population was quite large in the wild, even though its distribution was not only in West Africa, the distribution of this rhino expanded to include South Africa.
