It is estimated that over 99 percent of all species that have ever lived on this planet have gone extinct. That accounts for over five billion species that have been completely wiped off the earth. The number currently existing today is between 10 and 14 million, and only 1.2 million of them have been documented. That leaves just over 86 percent that have yet to be labeled.
Mass extinctions are a rarity, however solo extinctions are a relatively common event. Quite recently, scientists have started to record extinctions and have been shocked to learn the extremely high death rates. Most of these species were never properly documented previously. Scientists now are predicting that by 2100 close to half of all animal and plant species will go extinct.
Typically, it takes about 10 million years from when a specie arrives, until it becomes extinct – with the exception of what is called living fossils. For millions and millions of years, they survive almost no morphological change. We can see these living fossils in the forms of alligators and crocodiles today, they have been here since the time dinosaurs roamed the planet. This is hopefully good news for humans, as we have only been here for around 180,000 years. A species will be wiped out when a higher up species depletes them, or when living conditions can no longer support their life. Or, in the very rare instance, a disease will kill them off.
Here are some diseases that have totally diminished species, or have been close to wiping them out…
9. Sylvatic Plague
The bubonic plague was the worst epidemic to ever devastate human life. It killed off about 25 million lives, as it spread through fleas on mice. Now a similar disease has arrived called sylvatic plague. It has attacked various prairie dog populations in towns on the Fort Belknap Reservation, and has now infected over 3,000 acres.
Not only has it reaped havoc over prairie dogs, it is now significantly affecting predators that hunt them. Take the black-footed ferret for example, gophers are their number one food source. If their food source disappears, so will they. And to add insult to injury, the black-footed ferret is one of the most endangered species on earth already.
Thankfully, scientists now have a vaccine for it. Peanut butter is one of the prairie dog’s favorite foods and it actually helps fight against the plague. Scientists mix peanut butter with vaccines, and distribute it all over their habitat. They have also been injecting vaccines into the ferrets, along with using insecticides to kill fleas. Hopefully, doing this can replenish their population, and will not affect anymore animal species.
8. PBFD Virus
Psittacine Beak and Feather Disease (PDFD) victims are lovebirds, cockatoos, parrots and macaws. PDFD virus also attacks even more seriously endangered species of all sorts of tropical birds. For instance, the New Caledonian Rainbow lorikeets, which can easily spread the disease to other nearby species.
This virus when picked up by young birds is almost 100 percent fatal. PDFD likes to hide in feathers and is easily transferred to others. It spreads through direct contact, feather dust, inhalation, and contaminated surfaces, which will most likely lead to death. Symptoms show disfiguring, irreversible feather damage, lesions, twisted beaks and devastating weight loss. Scientists have yet to find a cure.
7. Sarcoptic Mange
This disease is spread through animals that are alive, as well as dead carcasses. It most likely will be carried and be distributed by foxes. Sacoptic Mange can also be found in wolves, lynx and wombats, along with other species. It has already wiped out red foxes on the island of Bornholm in Denmark. It is spread through mites that burrow in the skin of their victims, and can spread through the skin of the animals to others. It causes massive hair loss and terrible itching, which leads to organ damage, weight loss, then death. There has yet to be a cure found for this awful disease.
6. Chronic Wasting Disease
Chronic wasting disease (CWD), is life threatening to elk and deer populations. In 1957, in Florida, the key deer species was down to just 27 due to CWD. Now their population has risen to approximately 800. The Virginia white-tailed deer is now endangered thanks to CWD, along with car collisions and human interactions. It will not be long before they are completely gone.
CWD is similar to mad cow disease, as it attacks the brain and it does not take long to become fatal. Symptoms show a weakened body and weird changes in the animal’s behavior. It leads to drinking a substantial amount of water, along with extreme salivation, as they walk with their ears and head down. Death inevitably follows shortly after.
Europeans arrived in Australia back in 1788, in an attempt to colonize the continent. At the same time, they brought rabbits with them. By the 1920s, the population of wild rabbits skyrocketed to over 10 billion. These rabbits destroyed Australia’s natural ecosystem by gobbling massive amounts of food which forced other animals away.
Rabbit hemorrhagic disease virus (RHDV), has now wiped out over 60 percent of the rabbit population. That disease was far more successful than previous poisoning attempts. Thanks to RHDV, it has allowed rodents to increase their numbers, which otherwise were almost extinct. Vegetation has started to grow again, and kangaroo numbers along with other species have started to bounce back. For such a brutal disease, it sure has proven to be very beneficial to other species.
We think of parasites as the ones that are carrying the deadly diseases, although not all of them are these death carriers. Scientists believe that some actually help build a stronger immune system in some animals. There are some parasites that when exposed to young animals, will help them become immune to them later in life. And those animals that are not exposed young can become vulnerable when they mature.
A type of flightless bird out of New Zealand called a Kakapos has a population less than 200. It was being killed off by a tapeworm, which is now extinct, allowing this bird to come back from almost being completely killed off. There are parasites that affected the spotted kiwis, both of which now are extinct. Parasites sometimes have to go extinct to save other species, and other times they help save them.
Chytridiomycosis or “chytrid”, is a deadly fungus that has preyed upon salamander and frog species. In just the last three decades, it has put over 200 amphibian species into a cataclysmic decline, and has made some face extinction. Since the early 2000s, chytrid has drove 30 species to extinction, and five of them had never been previously seen.
The fungus can be found on all continents with the exception of Antarctica. It damages the outer layer of a salamanders’ and frogs’ skin. These amphibians use their skin to absorb water and to take in nutrients, but this fungus will suffocate them to death. Scientists continue to research for a cure.
2. Sea Star Wasting Syndrome
Sea star wasting syndrome first appeared in the 1970s. The last plague began in 2013 and it startled scientists at how fast it spread. Starting on the pacific coast of Mexico, it quickly made its way up to Alaska. The disease affected 19 species of sea star, and has caused three species to go extinct. By 2014, 87 percent of places surveyed had become infected. It was the biggest disease outbreak in recorded marine history.
Wasting disease spreads through physical contact while attacking the immune system. Sea stars then suffer an infection that leads to abrasions, which leads to arms falling off. Finally, they turn to mush. It only takes two days for death to occur after the lesions set in.
Scientists remain baffled to why this sudden outbreak occurred. Acidification and warmer water temperatures are possible causes. Wasting disease is now affecting sea urchins as well. As of now, there is no cure for it. Scientists are scrambling to help find a solution before it spreads to even more sea creatures.
It was first discovered in 1976, in the Democratic Republic of Congo, in Africa. Scientists believe it may have started in bats then carried over to other animals. It is easily spread from human-to-human through bodily fluids. We have recently seen epidemics of Ebola take place, especially in Africa, wiping out many people.
Early symptoms are a fever and a sore throat, which soon leads to more serious symptoms, such as organ failure of the liver and kidneys, both internal and external bleeding, and finally death. Not only has it devastated human populations, it has also hit other species close to our own kind. There is a huge variety of primates that call Africa home, especially the big populations of gorillas and our closest relatives, the chimpanzee. In just 40 short years, Ebola has overpowered close to a third of the planet’s species, putting gorillas on the endangered list. Thanks to frequent epidemics, entire populations have vanished.