Grey-faced Buzzard (Sashiba) and the Global Warming The Gray-faced Buzzard, Butastur indicus (Sashiba) is the most dominant
raptor in Japan (63 % at Irago Cape. /Hawk Migration Network).Flyway of Sashiba in Autumn, they moves from East Japan to Irago Cape of Atsmi peninsula (see Howk migration at Irago).  They move west to Sata Cape, Kagoshima, and down south the Ryukyu island-chain to Taiwan and South-east Asia (Higuchi, 2005). Miyako isl. is located in the middle of the ocean, 300 km away from Okinawa (see map).It's the most important stopping island They flies over 6 hoursn from Okinawa, and seemed too exhausted to run away from me. So the counts at Miyako isl. represents almost all population of Sashiba in Japan. |
 Global Warming and number of migratoryBlue-line chart shows the counts of Grey-faced Buzzard at Miyako isl., it declined
from roughly 50000 (1980) to10000 (2015), data /Nature Conservaton Society),
dot line shows a regression. Red-line shows the average temp. of it's breeding season (May-Aug at Tokyo) is increasing due to the Global Warming (data /Meteorological Agency). dot line is a regression. I'd say there’s a relations between Global Worming and the decline of Sashiba population, but the correlation coefficient is not high enough, there're various factors to consider such as deforestation of habitat and urbanization of wintering region and so on. It's an evidence that the Gloval Warming affects migratory hawks. Then the Bird-diversity on the globe will detereorates. #stopglobalwarming #keepbirdhabitat. |