People on the island like to describe Taiwan as the "kingdom of this" and the "hometown of that." One of the island's monikers being bandied about lately is the "Kingdom of Butterflies." This is because more than 400 species of the flitting insects make their home in the island's tropical, temperate and frigid zones, especially now in the middle of butterfly season. Decades ago, foreign entomologists came to Taiwan to study the diminutive creatures, and even today, some foreign tourists have been known to make special trips just for the chance to net one of the little critters of the order Lepidoptera.
On weekends, residents of metropolitan Taipei like to escape the urban jungle and head en masse for the hills of nearby Yangming mountain to climb the steps hewn in the trails leading to the top of this hilly area, which is preserved as a national park. From May 13 to June 20, they have another reason to go: the 2004 Yangmingshan Butterfly Season.
The big attractions this year are the Parantica sita niphonica and Parantica melaneus swinhoei. In the past, locals used to call the first appearance of the two species the opening of "the season of Parantica sita niphonica," although they likely used the common name for the species, which in English is "chestnut tiger." Large groups of these two butterflies have been seen flitting about Yangmingshan park since April. In past seasons, the number of chestnut tigers has reached 90,000.
Like some of the tourists that come to see it, the chestnut tiger is a migratory creature that crosses the sea to Taiwan. Japanese and Taiwanese lepidopterists have investigated the migratory species since the 1980s. It can be found in Taiwan, Japan, Korea, the Philippines and Malaysia.
Several years ago, researchers from different countries began cooperative studies of the chestnut tiger's migration patterns. Taiwanese specimens and those from Japan were found to have reached each other's territory. Japanese researchers would mark the wings of thousands of butterflies with felt pens and then set them free. Some turned up in Taiwan. In recent years, Taiwanese researchers used the same tagging method on butterflies caught on Yangmingshan, which were then found to have traveled back to Japan.
The highlight of the Yangmingshan event is the Chutzushan Butterfly Exposition, which was held May 22-23. In past years, the government would open a kilometer-long section of the military road to the public. This year, a much longer section, 3 kilometers, was opened to allow people to try and spot a butterfly or two. Also this year for the first time, the military allowed civilians to use Chungshan Hall in their pursuit of butterfly sightings.
Chungshan Hall was built almost 40 years ago. In the days after the ROC government's retreat to Taipei, it was the venue for meetings of the National Assembly. Since 2000, it has gradually opened for group tours. The government plans to turn it into a tourist attraction in the near future. Despite the lax regulations regarding tourists during butterfly season, photography was still forbidden in the military-controlled areas.
During the two days of the Chutzushan Butterfly Exposition, visitors could play a game designed to teach them about butterfly habitats. Shuttle-buses were provided to take visitors to butterfly-rich areas, and souvenirs and maps were sold at the expo.
Photographers like to catch the chestnut tiger resting on the brown flowers of the Eupatorium shimadai and feasting on its pollen. The flowers bloom in May and June, which coincides with the butterfly's annual residency in Taiwan. Butterfly connoisseurs therefore know that the secret is to wait by these plants until the insects show up. Eupatorium tashroi, which looks--and presumably tastes--quite similar, makes a good alternative.
The Eupatorium shimadai is often mistaken for an orchid, perhaps because part of its common name in Mandarin Chinese means orchid. In Taiwan, the flowers grow largely on Tatun Mountain, which is located inside the Yangmingshan National Park, and are rarely seen anywhere but the island's northern areas.
Many Chinese classical writers have mentioned the plant in their writing. In Songs of the South, an ancient Chinese anthology of poems written during the Warring States Period (475-221 B.C.), for example, the author describes the plant as a useful source of oil that women can use on their hair.
On Yangmingshan, the variety of caterpillar that will eventually become the chestnut tiger likes to munch on the dark green leaves and milky sap of the Marsdenia formosana, although on occasion it might settle for the Marsdenia tinctoria if that is what is available. The former is a rattan-like perennial herb with shrubs and tree-climbing vines. It belongs to the Asclepiadaceae, or milkweed family, and can be found throughout Taiwan, Orchid Island and the Ryukyu Islands. The worm usually enjoys gnawing down on the leaf veins before finishing off with the leaf edges.
Both the chestnut tiger and Parantica melaneus swinhoei, which is known as the "chocolate tiger," have transparent light-blue markings on their wings bordered by brown. Generally the chestnut tiger has the larger body of the two. In fact, it is a medium-sized species whose wingspan reaches 10 centimeters wide. Because it feasts on poisonous plants, it has few natural enemies in the insect kingdom, and therefore usually flies at its own, lazy pace, free of harassment even in the presence of butterfly-eating insects. The environment on Yangmingshan hosts tens of thousands of the butterfly every year.
The Parantica sita niphonica belongs to the subfamily Danaidae and can be subdivided into six species. There are 11 Danaidae butterflies found in Yangmingshan, making up about 85 percent of Taiwan's Danaidae species. Several other species are seen in the national park during butterfly season. Papilio polytes pasikrates, for example, can be found in southern Taiwan all year round and appears in the mountainous area of Yangmingshan in summer and sometimes autumn.
Pithecops fulgens is the smallest butterfly in the world, measuring only two to three centimeters across with its wings spread wide. It lives in northern Taiwan's mountainous areas. Because it is much more often seen in Wulai, locals have taken to calling it the "Wulai black-star gray small butterfly," although its more manageable English name is "blue quaker." On each gray wing there is a noticeable black spot.
Kallima inachis formosana is known by its informal name in Taiwan, the "dried-leaf butterfly." A master of disguise, its wings approximate the appearance of dry leaves, right down to the gritty details such as veins, musty spots and even what appear to be traces of worm bites. When resting with closed wings among twigs and leaves, it is hard to spot. Once it spreads its wings, however, it displays a striking yellow-and-blue pattern. Though few in number, the species can be found from Taiwan's flatlands to its mountainous areas. The adult butterfly likes to suck fermented fruit juice.
Pieris rapae crucivora is the most commonly seen butterfly in Taiwan. Its caterpillar likes to dine on vegetables, especially cabbage and broccoli, earning it the common name "white cabbage butterfly." The juice of these vegetables is also a favorite source of nectar for the adult butterfly. It is no surprise, therefore, that it is commonly seen on vegetable farms and is considered a pain in the neck by the farmers.
Other activities at the festival include butterfly photo exhibits and films, lectures on butterflies and guided tours to butterfly-rich areas. Guides are sure to point out the region's natural resources and geological features along the way.