At least seven species new to science have been found in the mountains of Bolivia by a university expedition.
By Alex Kirby
BBC News Online environment correspondent
The students found two frog species, two snakes, two toads and a lizard.
In a largely unexplored valley, they also found an owl not recorded before in Bolivia.
Experts say their discoveries suggest the country's overall variety of species may be greater than previously thought.
The finds were made in 2001 by students from the universities of Oxford and Glasgow, UK, and the University Major San Simon, Bolivia. Their expedition, Yungas 2001, was named after the rainforest of the eastern slopes of the Andes.
The forest where the new species were found has been designated a protected area by the Bolivian authorities. It is under threat from logging, burning and clearing for agriculture.
Frogs' key role
The team will publish detailed reports on what it found in several scientific journals.
Dr Michael Harvey is a tropical biologist at Florida International University, and an authority on Bolivian amphibians and reptiles.
He confirmed that the team had made genuinely new discoveries, and said several of the other species appeared to be range extensions or new additions to Bolivia's fauna.
The project leader, Ross MacLeod, said: "Fifteen per cent of the frog species in this forest are found nowhere else in the world, so these two new frogs are a particularly significant find.
"Throughout the world frogs in particular are known to be good indicators for habitat quality and environmental change.
Nomad from the north
"Many other species are still undescribed in the High Andes, and given the current pace of habitat degradation they may soon become extinct.
"We hope Bolivian conservation agencies can use these data to develop the first conservation management plan for this unique system and its key species."
The bird that excited the expedition is the cloud forest screech owl, known till now only in Peru. Aidan MacCormick, who worked on the bird surveys, said: "We were very lucky to discover a new population of the owl more than 1,000 miles south of where it was thought to live.
"Extending the known distributions of 70 bird species along with discovering new frogs, reptiles and insects is remarkable.
Insect treasure trove
"It just shows there are still hidden places on this planet that remain scientifically unexplored: a group of enthusiastic student biologists can make huge discoveries and take an important step towards protecting the world's biodiversity."
The team found many insects not recorded before. Darren Mann of Oxford University said: "The material includes numerous examples of insects not represented in British collections, and a large number of fly and beetle species new to science."
Ross MacLeod told BBC News Online: "There's a very high rate there of endemism, species that don't exist anywhere else. It's almost as though a different species had evolved in each valley.
"We think there'll prove to be more than seven new species when the analysis is complete."
The expedition was supported by the BP Conservation Programme, a partnership between BirdLife International and Fauna & Flora International which has been backed for the last 13 years by the energy giant BP.
The programme is now forming a partnership with two US groups, Conservation International and the Wildlife Conservation Society.
This year it is giving awards to 32 conservation projects in 21 countries, worth $565,000 (£340,000) altogether.
Species to benefit include turtles in Kenya and Indonesia, elephants in west Africa, bats in Slovakia and the Nicobar Islands, and dugongs in Vietnam.
Images courtesy of Yungas 2001.