Effects of Coastal Wind Farms on Bird Communities and Flight Paths: a Case Study in Taiwan

Wind power is going to flourish in Asia in the coming years. Given the dense human population in Asia Pacific, many wind farms in the region have been constructed offshore or on coastal wetlands, and even more are under... [ view full abstract ]

Wind power is going to flourish in Asia in the coming years. Given the dense human population in Asia Pacific, many wind farms in the region have been constructed offshore or on coastal wetlands, and even more are under planning. Yet hardly any information about their impacts on wildlife is known.
To study the potential impacts of coastal wind farms on birds in the East Asian-Australasian Flyway, we conducted monthly census on bird communities at two artificial wetlands (WG and YH) in Changhua coast, Taiwan, between 2009 and 2011. Together with neighboring tidal flats, the region hosts a large number of waterbirds during migratory seasons and in winter. The construction of a small-scaled wind farm along the northern and western coastline of WG set about in summer 2009, and its operation started in autumn 2010. Thus we were able to compare the bird communities prior to construction, during the construction phase, and during the operational phase of the wind farm in WG, while using YH as a control site. We also recorded the flight paths of birds across the coastline, to investigate the effects of turbines on bird behavior.
We found that bird abundance in the two sites in general fluctuated parallelly, which indicated that seasonal and large-scale dynamics were the more likely driving force. Nevertheless there was a weak tendency that bird abundance in WG gradually declined relative to YH, which was mainly due to the decrease of egrets. Whether this decline resulted from the construction of the wind farm was in need of further investigation.
We also found that, since the operation of the wind farm, proportionally fewer birds took the northern path to cross the coastline, while more birds took the western path. This corresponded to the spacing of the turbines: the turbines were 200 m apart from one another at the north while 500 m apart at the west. Birds were likely to avoid passing densely spaced turbines, while turbines 500 m apart from one another appeared no significant obstacle. Continuous monitoring is necessary to evaluate whether the lack of avoidance behavior might instead lead to higher collision risk.