Cloud forest and their butterflies in eastern Andes in Bolivia.

Cloud forests are upper montane rain forest, montane laurel forest, or more localised terms such as the Bolivian Yungas, have transition zones between the high Andes alpine and tropical Amazon flora and fauna. Amazon riwer system in South America has approx. 40% of the world's total forest land, approx. 70% of the world's animal and plant species, some of these reaches into the cloud forests. Once you get over 2400 meters altitude pops up plants which are known from North America and Asia as violets, blackberries and various heathers, grasses and orchids.

Many of the Yungas are degraded areas or tree formations in recovery who have not yet reached its climax vegetation, like the Fayal-Heath of Macaronesian laurisilva. The diversity of plants and animal species falls dramatically when you get over 2400 meters altitude. Cloud Forest appear from Venezuela to northwestern Argentina via Brazil Bolivia, Chile, Colombia, Ecuador and Peru

Males are usually found wiht small streams they gather in numbers, often several species together. They often sit wedged amongst small semi-submerged rocks and pebbles at the edge of shallow streams, or where small fords cross mountain roads. Females rarely settle on the ground, and are instead encountered in flight on mountain passes, or when feeding at flowers at cloud forest / grassland transition zones. Feedplants: Parasitic mistletoes, Phoradendron species. Caterpillars feed in small groups. Pupae are found in groups on tree trunks and look like bird droppings.

Also a big purplered Leafwing ; Brush Footed Anaea, Polygrapha tyrianthina, another Anaea which is deep blue with sickle-shaped wings and tails; Boisduval's Leafwing, Memphis moruus is also seen in the ravines.

There are a few Metal Wings, Riodinidae as; Sylphina Angel, Chorinea sylphina and Angularis Metalmark, Emesis angularis and various small skippers and some dark ringlet.

From the Cumbre pass 4672 m up in the snow, you drive 63.9 km along the world's most dangerous road (estrada da morte) past the Cascades de Sacremento Alto 2340 m. to Yolosa at 1075 m altitude in a tropical climate.
In 2006, the new road opened, so the section between Es Cotapata and Yolosa along the old Death Road is today used by tourism for mtb driving.