Range‐wide migration corridors and non‐breeding areas of a northward expanding Afro‐Palaearctic migrant, the European Bee‐eater Merops apiaster

Abstract

Across their ranges, different populations of migratory species often use separate routes to migrate between breeding and non‐breeding grounds. Recent changes in climate and land‐use have led to breeding range expansions in many species but it is unclear whether these populations also establish new migratory routes, non‐breeding sites and migration phenology. Thus, we compared the migration patterns of European Bee‐eaters Merops apiaster from two established western (n = 5) and eastern (n = 6) breeding populations in Europe, with those from a newly founded northern population (n = 19). We aimed to relate the breeding populations to the two known non‐breeding clusters in Africa, and to test for similarities of migration routes and timing between the old and new populations. Western Bee‐eaters used the western flyway to destinations in West Africa; the eastern birds uniformly headed south to southern African non‐breeding sites, confirming a complete separation in time and space between these long‐established populations. The recently founded northern population, however, also used a western corridor, but crossed the Mediterranean further east than the western population and overwintered mainly in a new non‐breeding area in southern Congo/northern Angola. The migration routes and the new non‐breeding range overlapped only slightly with the western, but not with the eastern, population. In contrast, migration phenology appeared to differ between the western and both the northern and the eastern populations, with tracked birds from the western population migrating 2–4 weeks earlier. The northern population thus shares some spatial traits with western Bee‐eaters, but similar phenology only with eastern population. This divergence highlights the adjustments in the timing of migration to local environmental conditions in newly founded populations, and a parallel establishment of new breeding and non‐breeding sites.

Diet of breeding Eleonora's falconFalco eleonoraein Algeria: Insights for the autumn trans‐Mediterranean avian migration

“…In contrast, the early passage of the European bee-eater we uncovered herein is surprising as it is known to begin southward migration in mid-August, with a peak in September (Cramp, 1998). However, our findings do corroborate records from South Sinai, Egypt (Arcilla et al, 2016), and a study showing that distinct geographic populations of European bee-eater may differ in their migratory phenology by 2-4 weeks (Hahn et al, 2020).…”

The Indo‐European flyway: Opportunities and constraints reflected by Common Rosefinches breeding across Europe

“…These southern European breeding sites might have been colonized by individuals with Turkish origin, while breeding areas further north, were likely colonized from the east by individuals with Russian origin (Bozhko, 1980). Thus, the population specific routes and the migratory divide between the Bulgarian and more northern populations may also reflect historic species colonization routes (Hahn et al, 2019). The larger northward detour of the Czech birds that cannot be explained by optimal routes might still be a remnant of historic routes and not yet adapted to the local conditions.…”

Migration strategy and site fidelity of the globally threatened Sociable Lapwing Vanellus gregarius

“…However, in Palearctic species with intercontinental flyways to both Africa and Asia it is usually the case that individuals occupying the western part of the range take the western flyway and those in the eastern part of the breeding range migrate take the eastern flyway, with a clear migratory divide in the breeding range. This pattern has been demonstrated in, for example, Asian Houbara Bustard Chlamydotis macqueenii (Combreau et al 2011), a number of tundrabreeding species of the high Arctic (Alerstam & Gudmundsson 1999), European Bee-eater Merops apiaster (Hahn et al 2020) and many European-breeding passerines (Møller et al 2011). Red-necked Phalaropes Phalaropus lobatus in the western part of the European breeding range migrate westwards to the east Pacific and those in the eastern part of the European breeding range migrate south to the seas off Arabia and East Africa (van Bemmelen et al 2019).…”