This week, researchers have announced the discovery of a handful of new species in Peru, including a night monkey, common shrew opossum and porcupine, and the extra great news is that they're all storybook levels of adorable.

In September 2011, ecologist Gerardo Ceballos from the Instituto de Ecología at the National Autonomous University of Mexico was part of a team of researchers who conducted a biological inventory of the species living in the Tabaconas Namballe National Sanctuary, which is located on the Atlantic slope of the Peruvian Andes, near the Peru-Ecuador border. Before they even got there, they caught a glimpse of a little grey fox, which, according to Ceballos, may represent the southernmost record of a grey fox in America. Or, he speculates at the Instituto de Ecología website, it could be a new species.

New species of mammals are not easy to come across nowadays, so the team was lucky enough to see this fox, but within the 29,500 ha sanctuary of misty cloud forests and alpine pastures, the researchers found an incredible eight new species of mammals, plus three amphibians.

Pictured above is the new species of night monkey, which the team have yet to name. Otherwise known as owl monkeys, because they're the only known truly nocturnal monkeys, night monkeys from southern Central America and northern South America are still quite a mystery. They're rare and very few have been observed in the wild, so we're not sure how long they live outside of captivity, or even what their average weight and length is. The Save the Primates website quotes a Peruvian hunter as having told a reporter in 2007 that, “The monkeys are elusive... in order to capture them, we have to take down 30 metres of forest around the tree where they are located."

What we do know about the members of the Aotus genus is that they have a very similar reaction to the human malaria virus that we do, making them popular research subjects. They also have unusual eyes, their colour vision is quite poor, probably due to the fact that it's not particularly useful in the dark anyway, but have superior spatial resolution at low-light levels, which helps them to spot insects moving around in the dark.

Like the wide-eyed tarsier, night monkeys also lack a tapetum lucidum. This is the tissue layer in the eye that causes it to reflect light, producing what's known as 'eye shine' in of many other nocturnal animals such as opossums, aye ayes, cats and reptiles. In a 1983 paper in the American Journal of Primatology describing two new species of night monkey, Philip Hershkovitz from the Field Museum of Natural History in Chicago writes, "In addition to my years of experience night hunting Aotus and other nocturnal mammals, I have tested with flashlight the eyes of well over 100 captive night monkeys, more than 60 of them in the outdoor compounds of the Proyecto Primates in Iquitos, Peru. The eyes of Aotus did not shine at any time or place like those of nocturnal animals with tapetum lucidum." Hershkovtiz also quotes , a pair of researchers called Muckenhirn and Montgomery, who radiotracked a night monkey in the 1970s, reporting that, “there were long periods during which we could not see or hear it. It moved quietly through the trees, did not vocalise, and usually did not drop rinds as it fed." A night monkey is no easy find.

Another new species discovered by Ceballos and his team is a common shrew opossum, also known as a marsupial shrew, and a member of the Caenolestidae family. According to a National Geographic report, this new species is near double the size of its closest relative, and is the largest found in the region so far. One of the team, Horacio Zeballos, mammalogist and curator at the Natural History Museum of Peru, said of the new species (roughly translated from Spanish) "I was totally shocked when I discovered among [the] small mammals a new species of South American marsupial Paucituberculata Order, much larger than the three previously known species." Caenolestidae living in Peru were first documented in the early 1980s, and gradually they've gone from being considered extremely rare to quite common in their home in the Andes mountains. A new species of small-eared shrew was also discovered on the trip.

A new species of large porcupine was also found, and it sports dark fur and extremely long quills, compared to other species of porcupine in the region. Ceballos reports that the other new discoveries include a new olingo, which is a nocturnal, possum-like mammal, and the recently described frog species Pristimantis bustamante. According to the team's audit, the sanctuary is home to 85 species of mammals, 326 species of birds and 23 species of reptiles and amphibians, and protects the endangered mountain tapir and spectacled bear. But the longevity of the site is threatened because of intense logging and illegal mining.

Earlier this year, The Wildlife Conservation Society announced the discovery of 365 new species in Peru's Bahuaja Sonene National Park, and a colourful new species of Peruvian bird was described in July.

Order my new book, Zombie Tits, Astronaut Fish and Other Weird Animals, here.