Why are there so few butterflies in the High Andes?

Andes is the world's longest mountain range that forms a continuous highland area along South America's west coast. The mountain range is about 7,000 km long, up to 160 km wide and has an average altitude of around 4,000 meters. The highest mountain in the Andes is Cerro Aconcagua in Mendoza province in Argentina about 100 km northwest of the provincial capital of Mendoza, near the border with Chile. It is with its 6,962 meters the highest mountain outside the Himalayas and thus on both the western and the southern hemisphere. The mountains consist of fold mountains and extinct volcanoes in the northernmost part of the mountain range is desert. Andes is composed mostly of granite and gneiss. The mountain range is newly formed and still growing.

The Andes high alpine flora and fauna occurred at roughly the same time as the Holarctic lineages which colonized South America in the Great American Interchange some 2-3 million years ago. Holarctic cold-adapted plants can quickly adapt to the special conditions and spread more quickly and will prevent many lowland tropical plants from adapting to highland conditions, and thus prevents the north upcoming plant interference from lowland plants. Butterflies are followed with the Holarctic plants from the north. Lowland butterfly fauna without coevolutionary history with Holarctic plants and their Phytochemistry, can not compete with the already migrant species from the north.

The flora and fauna above the treeline in the Andes is not particularly rich in species. One can mimic the same butterflies in the Rocky Mountains, North America, where there over the treeline are over 40 species. In the northern Andes in Colombia, there are just over 20 species. It is little wonder when you look at the world's richest biodiversity in the Amazon and up the eastern slopes of the Andes up to 2000 mh From there the species diversity decreases dramatically, especially over the 3000 meters at the tree line there are almost no butterflies species. This supports the theory of the migration that occurred from the north.

The White, Pieridae are exelent adapted to living in high mountains in the Andes: Chile, Bolivia, Peru, Ecuador, Colobia and Venezuela country but some species have developed the ability to live to over 4600 meters above sea level in the high Andes mountains. Rare species in genus Hypsochilas, Phulias and Pierphulias and are excellent examples of this, small butterflies very difficult to see, capable of withstanding the high, sparse vegetation and strong winds in mountain range. So particular adaptation has been in the mountain, which are among the species capable of living at higher altitude in the world. Hypsochila penai, has been seen to 5250 meters above sea level, while a specimen of Pierphulia isabella holds the record for being the greatest height flying butterfly see in the world: 5500 meters on the volcano Nevado Ojos del Salado. Nevado Ojos del Salado is a massive stratovolcano in the Andes on the Argentina-Chile border and the highest volcano in the world at 6,893 metres. It is also the second highest mountain in the Western Hemisphere and Southern Hemisphere and the highest in Chile.

Pierphulia isabella are familar to the sisterspecies Pierphulia nysias from Cumbre Pass, Bolivia in 4672 meters altitude.

In Bolivia, there are few species of butterflies in Pieridae genera: Colias feeds on legume. Piernini; Tatochila and Hypsochila, Reliquia, Phulia, Pierphulia as if the host plants are Crucifers and / or Tropaeolaceae. A few Lycaenidae and Fritilary Butterflies in the genus Yramea as if host plants are both Pansy, Viola and Rosaceae (Acaena). Few species in Satyrinae; Pronophilini, which is divided into two distinct groups: one in northern and Central Andes associated with the Andean Bamboo, the second in the Altiplano and Patagonia on Bundtgrass.

Hvorfor er der så få dagsommerfugle arter i Andesbjergene?

Andesbjergene er verdens længste bjergkæde, som danner et uafbrudt højlandsområde langs Sydamerikas vestkyst. Bjergkæden er omkring 7.000 km lang, op til 160 km bred og har en gennemsnitshøjde på omkring 4.000 meter. Det højeste bjerg i Andesbjergene er Cerro Aconcagua i Mendoza-provinsen i Argentina godt 100 km nordvest for provinshovedstaden Mendoza og nær grænsen til Chile. Det er med sine 6.962 meter det højeste bjerg uden for Himalaya og dermed på både den vestlige og den sydlige halvkugle. Bjergene består af foldebjerge og udslukte vulkaner og i den nordligste del af bjergkæden er der ørken. Andesbjergene består mest af granit og gnejs. Bjergkæden er nydannet, og vokser stadig.

Andesbjergenes højalpine flora og fauna opstod på nogenlunde samme tid som den store Amerikanske flora og faunaudveksling for 2 til 3 milioner år siden, Holarctic kold-tilpassede planter kan hurtigere tilpasse sig de specielle forhold og sprede sig hurtigere og vil udkonkurrerer de mange lavlands-tropiske planter fra at tilpasse sig til højlandet forhold, og dermed forhindrer de nordfra kommende plantearter indblanding fra Lavlandsfloraen. Dagsommerfuglene er fulgt med de Holarktiske planter fra nord. Lavlands sommerfugle faunaen uden coevolutionary historie med Holarktiske planter og deres Phytokemi, kan ikke konkurrerer med de i forvejen indvandrede arter nordfra.

Floraen og Faunaen over trægrænsen i Andes er ikke særlig artsrig. Man kan sammeligne dagsommerfugle i Rocky Mountains, Nordamerika, hvor der over trægrænsen er over 40 arter. I de nordlige Andesbjerge i Colombia er der lige over 20 arter. Det er lidt underligt når man ser på verdens rigeste biodiversitet i Amazonas og op på østskråningerne af Andes op til 2000 m.h. Derfra falder artsdiversiteten drastisk, især over de 3000 meter ved trægrænsen er der næsten ingen dagsommerfugle arter. Det underbygger teorien om den indvandring der er foregået fra nord.

I Bolivia er der Hvidvinger, Pieridae i slægterne: Colias som lever på Ærteblomstfamilien, Fabaceae. Piernini; Tatochila og Hypsochila, Reliquia, Phulia, Pierphulia som hvis værtsplanter er Korsblomstrede, Brassicaceae, Cruciferae og/eller Blomsterkarsefamilien,Tropaeolaceae. Nogle få Lycaenidae og Perlemorsommerfugle i slægten Yramea som hvis værtsplanter både er Violaceae og Rosaceae (Acaena). Lidt Satyrinae; Pronophilini, der er delt op i to særskildte grupper: et i det nordlige og centrale Andesbjergene forbundet med Andesbambus, den anden i Altiplano og Patagonia på Tuegræs.

The life history of Pierphulia nysias (Weyner, 1890) ssp. nysiella

An endemic butterfly species from the Cumbre, 4672 m. Bolivia

Nysias White, Pierphulia nysias is the world's smallest pieride wingspand 20 mm., which is an endemic species found only in the eastern Cordiller in Bolivia. The locality that I know exists in Cumbre, 4672 mh Just north of La Paz on the road to Coroico and Rurrenabarque. Its habitat that I know are quite small and lies in the actual passport, which constantly blows, rains, and often there is snow up there. A hostile place for a butterfly to live. It is reasonably tough, can fly for 4 + degrees in the drizzle for a few centimeters above the mountain's small stone surfaces. It often sit with their wings flat over ground and suck energy from the sun. It can be hard to shoot under these conditions, thin air with the wind all the time. It requires good health and not suffering from altitude sickness and height phobia.

Life history must resemble its sister species Pierphulia rosea found in Peru and Bolivia. Adult lay very few, very large eggs but may live more than three weeks. The larva, a Crucifer feeder, is skipper-like in appearance and lives in an individual silken nest within rosettes of the host. Growth is exceptionally slow, requiring as much as half again longer from egg to adult as pierines twice the size, reared under the same conditions.

Verdens mindste pieride; Pierphulia nysias (Weyner, 1890) ssp. nysiella

Pierphulia nysias er verdens mindste pieride vingefang 20 mm., som er en endemisk art der kun findes i de østlige Cordiller i Bolivia. Den lokalitet som jeg kender findes i Cumbre, 4672 m.h. Lige nord for La Paz på vejen mod Coroico og Rurrenabarque. Dens levested som jeg kender er ganske lille og ligger i selve passet, hvor der konstant blæser, regner og ofte ligger der sne deroppe. Et fjentlig sted for en sommerfugl at leve. Den er rimelig sej, kan flyve i 4 + grader i støvregn i få centimeter over bjergets små stenflader. Den sidder ofte med vingerne fladt over grunden, og suger energi fra solen. Den kan være svær at fotograferer under disse forhold, tynd luft med blæst hele tiden. Det kræver et godt helbred, og man ikke lider af højdesyge og højdefobi.

Livshistorie ligner højst sansynligt sin søsterart, Pierphulia rosea som findes i Peru og Bolivia; Hunnen lægger meget få, meget store æg. Larven, lever på korsblomstrede/Crucifer, der har bredpande/hesperidae-lignende udseende og bor i et individuel silkehylster rede i plantens bladrosetter. Væksten er usædvanligt langsomt, kræver dobbelt så lang levetid som fra æg til voksen som hvidvinger/pierider af dobbelt størrelse, der er opdrættet under de samme betingelser.

Lars Andersen observation of Nysias White, Pierphulia nysias

I saw P. nysias first time on 27 February 2007. I had no idea at that time there were as small white wings, it is not larger than 20 mm. in wingspan, as a small white Geometridae. A single female I also photographed, it has wider black drawing of the face. When I came home to Denmark, it was Tom Nygaard Kristensen who identify butterfly species.

La Cumbre, Yungas, elev. 4672 m. Enero-Febrero 2007 sitio 22

Two years later I rediscovered the same place on February 25, 2009, which I saw up to 10 butterflies flying around, which I also saw how it went down, because the weather was worse. The flap their wings flat over their backs and lie them down to one side.

La Cumbre, Yungas, elev. from 4300 m to 4672 m. Enero-Febrero 2009 sitio 50

This year on January 12, 2012 I was driving over the pass in good weather, unfortunately, I was pretty tired after the long flight, and suffered from inability to breathe, so I stopped not. On February 1st I drove from Caranavi over Cumbre to La Paz, but it rained and snowed.

On February 3, I was driving from La Paz to Cumbre, the weather did not promise, and after three hours as the weather cleared up a bit, I found two males on the site, the one I got good photos of, unfortunately, hit me after altitude sickness 3 hours up there, so I had to settle for this one visit. 2 days after I was so bad that I had to drive down to Coroico in the 1800 meters to get rid of altitude sickness. It was the last trip across the Cumbre 15th February, but there was snow everywhere up there.

Lars Andersen observationer af Nysias White, Pierphulia nysias

Jeg så P. nysias første gang d. 27 februar 2007. Jeg anede ikke dengang der fandtes så små hvidvinger, den er ikke større en 20 mm. i vingefang, som en lille hvid Geometridae. En enkelt hun fik jeg også fotograferet, den har mere udbredt sort tegning på oversiden. Da jeg kom hjem til Danmark, var det Tom Nygaard Kristensen der bestemte sommerfugle arten. Enero-Febrero 2007 sitio 22

2 år senere genfandt jeg den samme sted d. 25 februar 2009, der så jeg op til 10 dyr flyve rundt, der så jeg også hvordan den gik til ro, da vejret blev dårligere. Den klapper vingerne fladt over ryggen, og ligger dem ned til den ene side. Enero-Febrero 2009 sitio 50

I år d. 12 januar 2012 kørte jeg over passet i godt vejr, desværre var jeg temmelig træt efter den lange flyrejse, og led af besvær med at få vejret, så derfor stoppede jeg ikke. D. 1 Februar kørte jeg fra Caranavi over Cumbre mod La Paz, men det regnede og sneede.

D. 3 Februar kørte jeg fra La Paz op til Cumbre, vejret så ikke lovende ud, og først efter 3 timer da vejret klarede lidt op fandt jeg 2 hanner på lokaliteten, den ene fik jeg gode fotos af, desværre ramte højde syge mig efter 3 timer deroppe, så jeg måtte nøjes med dette ene besøg. 2 dage efter var jeg så dårlig at jeg måtte køre ned til Coroico i 1800 meters højde for at blive fri for højdesyge.

15th February; It was the last trip across the Cumbre pass, but there was snow everywhere up there.

D. 15 februar blev den sidste tur over Cumbre, men der lå sneen overalt deroppe.

Papas Nativas del Altiplano Norte de La Paz - Bolivia

On February 15 in the evening I take the last photo in Bolivia out the window at Milton hotel on Calle Illampu in La Paz.

D. 15 februar om aftenen tager jeg det sidste foto i Bolivia ud af vinduet på hotel Milton på  Calle Illampu i La Paz.