Swallows perch on power lines at Shaodong County, Central China's Hunan Province at dusk July 24,2008. Locals say that since 2000, about fifty or sixty thousand swallows gather here every summer and leave after the autumn Equinox. They fall on the wires at dusk and fly away in the morning. No one has been able to explain this phenomenon. [Asianewsphoto]