The effects of weather and climate changes on the timing of autumn migration of the common crane (Grus grus) in the north of Moscow Region

Abstract

A significant correlation between the beginning of the formation of migratory congregation and the ultimate transition of minimal daily temperatures below 10°С was revealed (r_s = 0.52, р < 0.02). Departure of common cranes from the north of Moscow Region usually occur_s between September 15 and October 15, on 28.09 ± 5 days on average. A significant trend for the shift of this event to later dates (r_s = 0.66, р < 0.002) was apparent from the data collected during 19 year_s (in 1994–2012). The date of departure of the cranes is affected by the ultimate transition of minimal daily temperature below 0°С (r_s = 0.64, р < 0.003), the abundance of precipitation (r_s = 0.49, р < 0.03), and the number of days with precipitation (r_s = 0.51, р = 0.026). Cranes stayed at the migratory autumn stopover for longer periods during rainy seasons.