Changes in the timing of spring and autumn migration in North American migrant passerines during a period of global warming

摘要: Butler (2003) used first arrival dates (FADs) of 103 migrant birds in northeastern USA and found that both long-distance migrants (LDMs; wintering south the USA) short-distance (SDMs; southern arrived earlier second half 20th century than they had first, consistent with scenarios global warming; trend was stronger SDMs. Using FADs to characterize migration systems can be problematic because are data from one tail a distribution, comprise mostly male population may not correlate well balance period. also provide no information about autumn migration. This paper uses banding dataset Long Point Bird Observatory, Ontario, for 14 passerines period warming (1975–2000), taking these issues into account. The were filtered minimize effects unequal netting effort (147 491 resulting records), passage then calculated each season year 1st, 2nd 3rd quartiles regression analysis. Only two 13 species analysed spring showed significantly times, although overall towards migration, especially among Autumn responses more prevalent, however, some cases dramatic six showing delayed (four SDMs, LDMs). Two LDMs exhibited Where occurred, sexes appeared contribute change. occurred autumn, adults hatch-year at least cases. FAD results those Butler, but when whole is considered, change far universal fact substantial complex autumn.