Crow butterflies of the genus Euploea overwinter in the Maolin Valley in Taiwan. (Photo credit: Laura Kraft)

By Laura Kraft

This post is the seventh in the “Travel Bug” series by Laura Kraft, a recent graduate from the University of Georgia, who is chronicling her travels in Asia from an entomological perspective. See earlier posts from the series.

Laura Kraft

Late January in the Northern Hemisphere means cooler temperatures, but it was nothing new to me to be sweating in the sunny weather while hiking in the verdant valleys of Maolin, Taiwan. I have been traveling through Southeast Asia since November and had been looking forward to cooler temperatures in Taiwan. I turned a corner to a particularly sunny section of the trail and stopped fast. All of the sudden, there were dozens of brown and purple butterflies just waking up, flitting quickly through the sunny patch en route to flowering plants with nectar.

The Purple Butterfly Ecological Park overlooks the Maolin Valley in Taiwan. (Photo by Laura Kraft.)

Whereas I had traveled north for relief from hot temperatures, these butterflies had migrated south from northern areas of Taiwan to the warm, sunny valleys of southern Taiwan to avoid chilly temperatures. I came to Maolin to see the overwintering site of four species of crow butterfly in the genus Euploea (E. tulliolus koxinga, E. mulciber barsine, E. eunice hobsoni, and E. sylvester swinhoei). The only other butterfly in the world that overwinters in a valley like the crow butterfly is the monarch butterfly, which migrates to southern California and Mexico.

Crow butterflies in the genus Euploea migrate south to the warm, sunny valleys near Maolin, Taiwan, to overwinter. (Photo by Laura Kraft)

The crow butterflies have been traveling to these valleys for a long time, well before the earliest memories of the local indigenous Taiwanese who live in the valley with them. Two local tribes in particular revere the butterflies that visit every winter: the Rukai tribe and the Paiwan tribe, both located in the nearby Sandimen Township. A visit to these tribes reveals butterfly motifs on everything from their traditional clothing to buildings to signs on shops. While Taiwan’s numerous exotic butterflies used to be sold to collectors, they are valued more today as a tourist attraction, bringing visitors from December to March to the mountains north of Kaohsiung City.

Ribbons featuring a butterfly motif often adorn the traditional clothing of the indigenous tribes of Sandimen Township in Taiwan. (Photo by Laura Kraft)

Besides an interest in tourism, there has also been an increase in interest for the conservation of these migrating butterflies, led greatly in part by Chan Chia-Lung (詹家龍) of the Butterfly Conservation Society of Taiwan.

I was able to interview Pin-Chu Lai, a volunteer who worked under Chan in 2011. She is now a graduate student at the University of Georgia. Together with a group of 25 other students, Pin-Chu traveled to Maolin in January 2011 to tag butterflies, using a marker to write the location and date where they were caught on their wing. They also noted butterflies that had already been marked and where they came from to better understand the migratory patterns of these butterflies.

Two volunteers working under direction of Chan Chia-Lung at the Butterfly Conservation Society of Taiwan mark a butterfly to help track its migration across the island nation. (Photo by Coco Hsueh.)

When they migrate in late November to southern Taiwan, the butterflies cross a few highways, which in some years are shut down to protect the hundreds of butterflies passing over per minute. Recently, mesh bridges over the highway have been put up during migration periods to try and force the migrating butterflies up and over the moving traffic on the highway. Data collected by the volunteers can help determine where more of these bridges may be needed and where more conservation efforts should be focused.

Pin-Chu Lai volunteered to collect data on crow butterfly migration in 2011 and is now a graduate student at the University of Georgia. (Photo credit: Jean Liu)

Pin-Chu first heard about the volunteering opportunity from a friend in the entomology department at the National Taiwan University in Taipei, where she was studying at the time. Chan recruits from entomology students in Taiwan because they are best at delicately handling the butterflies to mark them for the study. Before volunteering, Pin-Chu had never visited the butterfly migration site. She was overwhelmed when they hiked in to the field site the first day, and she looked up to see approximately 50 butterflies flying overhead. Before that, she had respected butterflies but had no special attachment to them. After visiting Maolin, her perspective changed: “After seeing hundreds of them in front of me in person, that [changed] me a little bit in my mind.” Hopefully, as more tourists visit the site they will be inspired with a similar reaction and interest in conservation of these butterflies and their overwintering valleys and migration routes.

Assorted butterflies, including many crow butterflies, feed on flowering plants in Sandimen Township, Taiwan. The photos here were taken over approximately 12 seconds. (Photo animation by Laura Kraft)

Laura Kraft is a recent graduate from the University of Georgia who is taking a year off to travel the world before returning home to start a Ph.D. program in the fall of 2017.