Monday, 16 July 2012

Extinction in the Animal World

Scientists hold that more than 99 percent of the species that have ever existed are now extinct. Each year, between 0.01 and 0.1 percent of all species become extinct.

Now, if the low estimate of the number of species out there is true and there are around 2 million different species coexisting with us on planet Earth, then that means between 200 and 2,000 extinctions occur every year. But, if the upper estimate is true, which is 100 million different species, then between 10,000 and 100,000 species are becoming extinct each year.

Both estimates are actually high. In fact, the extinction rate we are witnessing these days is between 1,000 and 10,000 times higher than the natural extinction rate. Right now, one species is going extinct every 20 minutes. Yep. Other studies estimate that it’s 150-200 species per day.

Enjoy this collection of extinction in the animal world before we, too, become extinct.

Golden Toad, or Golden Toad of Monteverde or the Monte Verde Toad
Incilius periglenes), 1989 
Scientists aren’t totally sure what led to this Costa Rican toad’s decline, though the best theory is that the El Nino weather pattern along with climate change and airborne pollution dried up the pools and ponds the toad lived in.

Western Black Rhinoceros or West African Black Rhinoceros
(Diceros bicornis
longipes), 2011
A subspecies of the black rhino which lived mainly in Cameroon, the western black rhino was a victim of rampant poaching, even after protections were issued in the 1930s. Scientists searched for any signs in 2006 and came up empty, and it was officially declared extinct in 2011. The other three remaining subspecies of black rhinos are also critically endangered.

Poʻouli or Black-faced Honeycreeper (Melamprosops phaeosoma), 2004

Non-native species, particularly pigs, cats, and rats have wreaked havoc on Hawaii’s ecosystem over the last few centuries, and most likely contributed to the decline of this unique bird. After an unsuccessful effort to get the last few remaining birds to breed, the last bird died in 2004. Technically, it’s still listed as “critically endangered,” but no birds have turned up in the wild after extensive searching for the last few years.

Saint Helena Earwig (Labidura herculeana), 1967
Even though it hasn’t officially been classified as extinct, but this freaky bug from the island of St. Helena in the south Atlantic hasn’t been seen alive since 1967. Searches in ’88, ’93 and ’03 turned up empty. Hm.

Conondale’s Gastric-brooding Frog or Platypus Frog (Rheobatrachus), 1983
Endemic to Australia, this frog was first discovered in 1973. What makes it unique is that it swallowed her eggs after they’re fertilized, eventually ‘birthing’ fully developed young frogs out of its mouth. The last one of its kind died in captivity in a laboratory in 1983. Since the mother is able
to shut off her stomach acid while carrying her young in her stomach, scientists had hoped to learn something about how to cure human ulcers from the frogs.

Pyrenean Ibex (Capra pyrenaica pyrenaica), 2000
The last of this subspecies of Spanish ibex died in the wild in 2000 when a tree fell on her. Scientists had taken samples of the last ibex’s DNA in 1999, and in 2009 they mixed the DNA with domestic goat eggs to create a clone. However, the cloned baby ibex died shortly after birth due to lung defects.

Caribbean Monk Seal, or West Indian Seal or Sea Wolf (Monachus tropicalis), 2008
Although the last one seen alive was in 1952, it wasn’t until 2008 that the Caribbean monk seal was finally declared extinct. Christopher Columbus recorded killing a few of these seals when he arrived in the Caribbean. They were also hunted extensively during the 1700s and 1800s for their blubber, which was used as oil for lamps and machinery.

According to the notes from a zookeeper at the New York Aquarium, which had a few of these seals in the early 1900s, they had a habit of spraying water from their mouths at visitors who leaned in too close over the railing.

The extinction of the Caribbean monk seal also meant the extinction of the Caribbean monk seal nasal mite — an insect that only lived inside the nose of this species of seals. Apparently, the only specimens of said mite were recovered a few decades ago from the nasal passages of a single captive, and presumably stuffed-up, seal.

Pinta Island Tortoise, or Pinta Giant Tortoise, Abingdon Island Tortoise, or Abingdon
Island Giant Tortoise
(Chelonoidis nigra abingdonii),
Lonesome George was a male Pinta Island tortoise and the last known individual of the subspecies. His exact age isn’t known, but he was estimated to be over 100 when he died on June 24, 2012.

Javan Tiger (Panthera tigris sondaica), 1994
Loss of habitat due to farming was the chief killer for this distinct subspecies of tiger that lived on the Indonesian island of Java. The last area in which they lived was in the highest mountain of Java. Records show that a tiger was killed there in 1984; by 1993, scientists couldn’t find any evidence of Javan tigers still living in the area.

Canarian Oystercatcher, or The Canary Islands Oystercatcher, or Canarian
Black Oystercatcher (Haematopus meadewaldoi), 1994
Photo of an African black oystercatcher, which is nearly visually identical. These shorebirds lived on the Canary Islands off the coast of west Africa, and died out due to depletion of its shellfish food source due to commercial fishing. It’s unclear exactly when the last birds died. Local lighthouse keepers and fishermen said they hadn’t seen it by 1940, but reports of sightings were still common through the 1980s. By 1994, it was officially declared extinct. Only four specimen of stuffed birds exist in museums today.

Mariana Mallard or Oustalet’s Auck (Anas oustaleti), 2004
Living only on three small Pacific islands, including Guam, habitat loss from draining marshes for agriculture and damage to the islands during World War II was the main reason for this duck’s extinction. The last pair of ducks were spotted in the wild in 1979, and the last known pair in captivity died at Sea World in San Diego in 1981.

Ivory-billed Woodpecker (Campephilus principalis), 1994
After habit loss of the swamps of the southern U.S, the last definitive sighting of the Ivory-billed Woodpecker was in the 1940s. Since then, there have been multiple reports of sightings. Then in 2002, an audio recording of the distinct sound it makes when pecking a tree sparked a flood of scientists and birders to come search for it. Despite some promising leads and tantalizing clues, the bird still remains officially extinct.

The Mexican Grizzly Bear (Ursus arctos nelsoni), 1964
Unlike popular belief, bears do not only live in cold habitats. The Mexican grizzly, like the grizzly which lives in the northern U.S. and Canada, are both subspecies of the brown bear. This Mexican subspecies was hunted to extinction by ranchers because the bears were killing their livestock. Only 30 were left by 1960; by 1964, it was considered extinct.

Japanese Sea Lion (Zalophus japonicus), 1974
Commercial hunting along with habitat loss due to WWII did these seal lions in. There were a only few sightings in the 1960s, and a baby was caught in 1974. In 2007, the government of South Korea announced a plan to introduce the closely related California sea lions into areas where the Japanese sea lion once lived.

Baiji Dolphin, or Chinese River Dolphin, or Yangtze River dolphin (Lipotes vexillifer),
Declared extinct in 2006, a video of what appeared to be a Yangtze River Dolphin was taken in 2007. The species is still considered “functionally extinct,” meaning that if there is only one of a few old creatures alive, no new ones will be born.

Alaotra Grebe, aka Delacour’s Little Grebe or Rusty Grebe (Tachybaptus rufolavatus),
This small diving duck lived primarily in one lake in Madagascar until habitat loss and predation by carnivorous non-native fish species killed it off.

Dusky Seaside Sparrow (Ammodramus maritimus nigrescens), 1987
A native of the east coast of Florida, this species rapidly died out from DDT pesticide spraying and its habitat being taken over for use by NASA for the Kennedy Space Center. The last know bird died in 1987, and was officially declared extinct in 1990.

“Extinction is the rule. Survival is the exception.”
― Carl Sagan



The Most Unusual and Unknown Creatures

The Most Unusual and Unknown Creatures II 

Animals That Are Not To Be Confused

Big Cat Hybrids 

Why Do Cats Give Massages? 

Why Flamingos Are Pinkish-Orange
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