"What I missed most was a cold beer after a long day's fieldwork," Andrén said.
Still, during two months of intensive work, the scientists were able to gather enough material for a 30-minute film about Iran's reptilian and amphibian fauna. (The pair produced four such films, broadcast on Swedish television, during the 1970s.)
The highlight was finding a population of Latifi vipers, named after Iranian researcher Mahmoud Latifi, deep in the sub-alpine Lar Valley in the Elburz Mountains.
Nilson and Andrén had studied the vipers, which are only found in that valley, in the 1970s. But the ongoing construction of a huge dam has since flooded much of the viper's habitat.
"We didn't know if the species had survived," Nilson said. "It took us three days to cross a lake and reach the inner part of the valley. There, we found an undisturbed area with an estimated population of a few hundred adult vipers. It was fantastic."
Other discoveries were somewhat accidental. Traveling near the city of Yassuj, the scientists decided to stop along a mountain wall. There, they found a unique blue-tailed lizard scaling the steep slopes.
"We immediately realized this was a new species that had never been found anywhere," Andrén said.
Species related to the blue-tailed lizard occur on the Arabian Peninsula, suggesting that the lizard may have traveled to Iran from Arabia millions of years ago when there was a land bridge across the gulf.
The blue-tailed lizard was given the name Lacerta yassujica. Three of the other reptiles that the scientists discovered in Iran are still waiting in Sweden for their scientific names.
Many venomous snakes in Iran are being collected for the production of antivenin. Scientists warn that this practice is threatening the survival of some of the snakes.
"Several times we heard about very good snake hunters cleaning an area completely of venomous snakes," Andrén said.
Snake hunters are even collecting the rare Latifi vipers.
"When you have been working for several years in different parts of the world, like we have, you realize that these animals are not looked upon as so important by most people," Andrén said. "They are becoming more and more rare, and they need protection."
Identifying unknown species is vital to the task of protecting them. There are some 1.8 million known species of animals in the world today. But scientists believe there may be as many as 20 million species, including small organisms like parasites and worms, out there.
Nilson says vipers have a fossil record that dates back 15 million years. "That means they are very good survival machines. We should have respect for these species. We should not be allowed to exterminate them."
SOURCES AND RELATED WEB SITES