The fear is of a process similar to that which happened in Hawaii, where foreign parasites caused the extinction of 30% of the endemic bird species on the island.
The Galapagos Islands are an archipelago of dozens of islands in the Pacific Ocean with a total area of about 8000 square kilometers. The islands were formed by volcanic eruptions above a "hot spot".
Their location close to the equator and far from the land allowed the development of many endemic (unique) species, which enjoy the food carried on the Humboldt Current, a cold water stream rich in nutrients coming from the south.
The Galápagos Islands became famous following the visit of Charles Darwin who identified the different species of pharaohs on each island, and consequently received the inspiration to develop the theory of the process of evolution driven by natural selection.
Even before Darwin's visit, the islands were used as a "refueling station" for ships whose sailors loaded the giant tortoises as "cans" and thus contributed to the extinction of the tortoises. Also, while loading the turtles, the sailors brought goats down to the shores, and these competed with the turtles for the food. Rats from the ships invaded the islands and began the systematic extermination of reptiles and birds. This is how visitors "contributed" to serious damage to the variety of species in the Galapagos. It was only in the twentieth century that the activity of preserving and maintaining the natural environment of the islands began.
Today there is a ban on bringing farm animals or domestic animals to isolated islands, there is an activity of exterminating rats and removing stray goats from many islands, and there are also centers that deal with the proliferation of endangered species, especially turtles.
The activity of conservation and return to nature of various species is positive and correct, except that today According to BBC,
Many species in the Galapagos are facing two new environmental dangers: parasites that cause fowl fever (malaria) and a significant increase in the frequency of "El Nino". According to researchers, the dangers are multiplying because of global warming.
Zoologist Dr. Patricia Parker Dr. Patricia Parker from the University of Missouri in St. Louis (University of Missouri St Louis-UMSL), says that "the situation is especially dangerous for species that live in small populations", the fear is of a process similar to the one that happened in Hawaii, where foreign parasites caused the extinction of 30% of the endemic bird species on the island. To this day, a similar fate has been avoided for Galapagos birds. The parasite (Plasmodium) that causes fowl fever develops in transit through the digestive tract of an insect (mosquito). In order to be able to complete the life cycle, the parasite must reach the insect's salivary glands and through a bite is transferred to the bird. Through the circulatory system the parasite reaches the bird's liver where it multiplies and returns to the blood. An insect that will bite the bird, will suck infected blood and the cycle starts again.
But not all birds are suitable surrogates. It turns out that many of the birds that are special to the islands are not suitable, and even if they bite, the parasites will not develop in them (until they develop mutations). Those who are to blame for the spread of the parasites are those who brought to the islands chickens, ducks and a species of cuckoo (Crotophaga ani) brought by the settlers as "tick droppings". All of these constitute a suitable source and reservoir for the development and spread of the parasites. One of the foreign species that serves as a host for the parasite are imported rock pigeons. In a successful operation, large populations of rock pigeons were eliminated on the isolated islands.
The danger that is already being realized is that genetic changes (mutations) will occur in the parasite that will allow it to reproduce also in local birds. Dr. Parker, who participated in research on avian malaria in the archipelago, fears that the spread of the epidemic and damage to the local species is only a matter of time" or "may happen soon. According to her, the parasite has already developed mutations that allow it to reproduce in populations of yellow terns and Galapagos penguins, two species endemic to the islands.
More of the topic in Hayadan:
- Endangered Species of the Galapagos Islands (2007)
- Islands in the Humboldt Stream
- Darwin's living legacy
The research is being carried out by researchers from the University of Missouri in collaboration with the St. Louis Zoo, the Charles Darwin Foundation and the Galapagos National Parks. It turns out (again) that the unique species in the Galapagos are infected by the parasite but do not take part in the parasite's life cycle, and the parasite does not complete its development. The researchers say that if it turns out that one of the species (chickens - or cattle ducks) is the main distributor of the parasite, the Galapagos Parks Authority will be forced to remove the population to prevent an epidemic, since once the parasite adapts to local species the disease will get out of control.
In the meantime, they are trying to find out who the imported mosquito is that spreads the parasite, identify it and eliminate it, but it turns out that preserving local species can be difficult and will not amount to preventing the spread of malaria. This is because one of the most studied climate phenomena that threatens the islands is El Nino. According to the researchers, the "El Nino" events are becoming more frequent and extreme and they are harming the animals in the Galapagos. During the El Nino events that occurred between 1982 and 1996, the penguin population dropped to about 300 individuals. The frequency of the events does not leave populations time for recovery and regeneration, which may lead to extinction.
The impact of El Niño is in the Humboldt current. The current that brings with it a lot of food is diverted back, meaning the water around the islands is "empty" of food. Added to this is the warming of equatorial waters, the life in the water is disappearing and the bird populations that feed on the sea are dying.
The famine during the "El Nino" weakens the birds and increases their vulnerability to malaria parasites. The frequency of "El Nino" and the danger of fever are a deadly combination that could wipe out many species. Already today there is a danger to the penguins, the local cormorant (which does not fly) and the mangrove pelican whose population is being destroyed by an imported fly Philornis downsi first identified in 1990.
According to a researcher at the Darwin Foundation, Francesca Cunninghame, in 2013, about 40% of the retired population was exterminated and 14 couples remained. According to Dr. Parker "Until recent years there was no extinction of birds in the Galapagos Islands and solutions must be found to prevent the archipelago from becoming a copy of Hawaii."
Let's hope they succeed.
One response
mozar!
The parasite, which is an inferior creature, "knows" how to change itself by mutations so that it is able to reproduce in a local chicken. And on the other hand, the local chicken, which is a more developed export, is not able to "develop" a defense that eliminates a virus.