From Japan’s electric metropolises seemingly pulled straight out of Akira or Blade Runner, China and Taiwan’s factories working 24/7 to supply our modern word with stuff and North Korea’s cold war cocoon with choreographed military parades to bamboo forests in the foothills of the Himalayas, alpine meadows on the slopes of a Hokkaido volcano and hidden mountain temples filled with the smell of burning incense, East Asia is an amazing place. On the nature side of things the region remains little studied and unfamiliar to those nature buffs in the general public more accustomed to seeing the savannas of Sub-Sarahan Africa or an Amazonian rainforest on the Discovery channel rather than Taiwan’s Central Mountain Range or Hong Kong’s Mai-Po wetlands. The biodiversity of the region is certainly under appreciated with enormous potential to provide scientific insight on the power of biological evolution.
As part of an ongoing, long-term research program bringing together an international team of investigators from Taiwan, Mainland China and Japan, I traveled to Japan with research partner Bailey McKay of the University of Minnesota to expand our study of the evolution of East Asia’s avifauna. Partnering with regional museums is absolutely critical if we are to learn anything about East Asia’s birds. Dr. Isao Nishiumi, senior zoology department curator and curator of the Center for Molecular Biodiversity Research at the National Museum of Nature and Science in Tokyo was a fantastic host for this trip. Dr. Nishiumi and his students have been exploring the islands of Japan and amassing one of the best collections of genomic resources the region has to offer. In collaboration with the Nishiumi lab and the National Museum we were allowed to tap into this resource returning over 600 DNA samples collected across nearly a dozen species of birds to the US for genetic analysis. With samples acquired from our other research partners during previous trips to Mainland China and Taiwan we have exhaustive sampling for several avian species found in the East Asian region.
The plan is to build large multilocus genetic datasets for each of our study species. Looking at how genetic variation is distributed across different populations will allow us to elucidate the evolutionary history of these species and better understand how many independent evolutionary lineages are in the region. With lab work on Chinese (Pycnonotus sinensis) and Taiwan Bulbul (Pycnonotus taivanus) nearly complete, with nearly 10,000 base pairs of nuclear intron data, we are ready to start building datasetsMeasuring specimens at the Yamashina Institute for Ornithology for other East Asian species. Several of our focal species are morphologically diverse with several distinct forms found throughout their range. Varied tit (Cyanistes varius) is a good example. This species on Taiwan is relatively small with white cheek patches while the same species on the Izu Islands is much larger with maroon cheeks. On the main islands of Japan the species is more variable in size and color, giving the species it’s name. Given this variation exactly how species are there? Just one or do the different variants isolated in their own little corners of the region represent distinct and evolutionarily independent genetic lineages? Other species we are looking at, like Brown-eared Bulbul (Microscelis amaurotis) and Japanese White-eye (Zosterops japonicus), also vary in appearance but the variation is more subtle and perhaps clinal, varying in a continual gradation from one population to the next. Teasing apart the likely complex evolutionary histories of these birds will require not only the latest molecular genetic tools but also good old-fashioned morphological measurements. Thanks to extensive collections at the National Museum of Nature and Science in Tokyo and the world famous Yamashina Institute for Ornithology in Abiko (Chiba Prefecture) we were able to measure morphology and photograph over 200 specimens. Together with measurements taken at the institutions of our other collaborators at the South China Institute for Endangered Animals and Taiwan Endemic Species Research Institute we’ve amassed an enormous morphological dataset to go with the molecular genetic data.
But, you can’t spend all your time in the lab or the collection and we did manage to get outside a bit. On these trips we like to gain first hand, field experience with the bird communities we are trying to understand. With trips to Miyake Island in the Izu Island chain and Hokkaido I’ve now seen our study area from top to bottom, from Taiwan in the south to Hokkaido in the north. Burned-out, little Miyake Island is a volcanic speck about a 7 hour ferry ride into the Pacific from Tokyo. A hint of sulfurous fumes is in the air as you approach the island. The entire population of Miyake has been evacuated more than once in the recent past due to volcanic activity. Miyake’s isolation has resulted in a small but unique avian community with endemic species like the Izu Thrush (Turdus celaenops) and regional island specialists like Pleske’s Grasshopper Warbler (Locustella pleskei).
If your favorite island flavor isn’t a tiny, volcanic cone sticking out of the ocean like Miyake then East Asia provides many others from which to choose. At the south end of the East Asian region is Taiwan. Straddling the Tropic of Cancer, plate grinding tectonic force has pushed central Taiwan to great heights creating a mountainous spine running nearly the length of the island that is home to some of the highest peaks in East Asia (the highest being Yushan at nearly 4,000m). At the north end our study area is Hokkaido. A large island, a little bigger than the state of Maine, Hokkaido the northern most of Japan’s main islanBlakiston's Fish Owl, Hokkaidods. The tree line is nearly 1500 meters lower in Hokkaido than in subtropical Taiwan. Forested volcanoes dot the island and rocky coastlines with breeding gull and seabird colonies lining the coast. Red Fox and Sika Deer are abundant and Brown Bear common. We were also lucky enough on this trip to see the endangered, and enormous, Blakiston’s Fish Owl (Bubo blakistoni) at two different location sin Hokkaido. With only less than 200 or so breeding pairs in Japan this was a great bird to see. At this far northern end of our study area you get a good feel for the latitudinal difference in the bird communities in East Asia. Gone are babblers and barbets of Taiwan’s subtropical broadleaf forests and the birds are more characteristic of Russia or Northern Europe with Eurasian Jays (Garrullus glandarius) and Winter Wrens (Troglodytes troglodytes, which are also in Taiwan but less common and at much higher elevation). The question is how are the bird populations on Hokkaido, and those on other islands in East Asia, connected to others in the region. If they are disconnected from other populations and therefore genetically isolated then when and how did their isolation come about? Clues to population history are imprinted in the genome and with the incredible sampling we have achieved through our collaborative team we can look at the distribution of genetic variation across several species and test hypotheses about their evolution.
The thousands of islands from Taiwan through the Ryukyu archipelago and the oceanic islands of the Izu and Bonin Islands to the main islands of Japan; Shikoku, Kyushu, Honshu and Hokkaido, the islands of East Asia provide the ideal natural laboratory to study evolution in action. Thanks to the efforts of our collaborators our team can know start to trace the evolutionary history of the region’s birds using an unparalleled dataset and the latest genetic tools. Hopefully our work will not only answer basic questions about evolutionary processes but provide a better estimate of the region’s biodiversity.
Thanks to our supporters including the National Science Foundation’s (NSF) East Asia and Pacific Summer Institute for funding Bailey’s summer in Japan, the NSF’s Major Research Instrumentation program for funding instrumentation at Cincinnati Museum Center’s Molecular Ecology and Systematics Laboratory and support from Cincinnati Museum Center and private foundation funding that allowed me to join Bailey in Japan this summer. But, special thanks to our host Dr. Isao Nishiumi and all his students and lab personnel who were so helpful during our time in Japan. Nishiumi is a fantastic addition to our international research collaboration. Domo arigato Nishiumi lab! Stay tuned to monofilia, cincyevolution and twitter for updates as the research progresses.