It took more than 30 years for science to formally identify the Caquetá titi monkey (Callicebus caquetensis) of Colombia as a new species. Now it probably won't last another 30 years unless it is protected, according to the International Union for Conservation of Nature (IUCN), which on Tuesday added the monkey and more than 1,900 other animals and plants to its Red List of Threatened Species.

The Caquetá titi monkey—which is both the size of a house cat and also purrs like one—was first observed in 1976, but decades of armed conflict in Colombia prevented scientists from locating it again until 2008. By then the monkey's forest habitat had been severely fragmented by agricultural development. In a 2010 paper (pdf) identifying the species and its distribution, scientists from National University of Colombia warned that the monkeys were probably down to their last 250 mature individuals, which are often separated from each other by barbed wire, grassy savannas and other obstacles. The scientists who identified the species recommended that it be added to Red List under the category of "Critically Endangered."

This 2012 Red List update, released in conjunction with the United Nations Conference on Sustainable Development in Rio de Janeiro (aka Rio+20), includes the titi and nearly 64,000 other assessed species to form what the IUCN calls "the world's most comprehensive information source on the global conservation status of plant and animal species." Other species making it onto the list for the first time include the "Critically Endangered" Burmese snub-nosed monkey (Rhinopithecus strykeri), "Endangered" cone snail (Conus mercator), and the ruby-eyed green pit viper (Cryptelytrops rubeus), which has been classified as "Vulnerable."

Meanwhile, four species have been moved into the Red List's "Extinct" category: two mollusks—the ovate club shell (Pleurobema perovatum) and the Fish Springs marsh snail (Stagnicola pilsbryi)—and two plants—Acalypha dikuluwensis and Basananthe cupricola.

Here's a breakdown of the 63,837 species now assessed on the Red List:

Extinct = 801

Extinct in the Wild = 63

Critically Endangered = 3,947

Endangered = 5,766

Vulnerable = 10,104

Near Threatened = 4,467

Lower Risk/Conservation Dependent* = 255

Least Concern = 27,937

*This is category is being phased out.

In addition, nearly 10,500 species appear on the list in the "Data Deficient" category, indicating that there is not enough information to properly assess those species' health.

Obviously there are many more species on Earth than appear on the Red List, but that's because so many remain to be assessed. The New York Times recently ran an infographic which pointed out that only 0.3 percent of insects, 0.02 percent of arachnids, 5 percent of flowering plants, 5 percent of mollusks and 29 percent of reptiles have had been scientifically assessed to determine their conservation status. The IUCN says the Red List, although not all-inclusive, "provides a useful snapshot of what is happening to species today and highlights the urgent need for conservation action."

Photo: The Caquetá titi monkey (Callicebus caquetensis) is critically endangered and he doesn't look happy about it. Photographed by Javier Garcia, courtesy of IUCN