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Understanding the relationship between migratory performance and fitness is crucial for predicting population dynamics of migratory species. In this study, we used geolocators to explore migration performance (speed and duration of migratory movements, migratory timings) and its association with breeding phenology and productivity in an Afro‑Palearctic insectivore, the European bee‑eater (Merops apiaster), breeding in Iberian Peninsula. Bee‑eaters migrated at higher travel speeds and had shorter travel duration in spring compared to autumn. Individuals that departed earlier or spent fewer days in‑flight arrived earlier to the breeding areas. Our results show overall positive, but year‑specific, linkages between arrival and laying dates. In one year, laying was earlier and productivity was higher, remaining constant throughout the season, while in the subsequent year productivity was lower and, importantly, declined with laying date. These results suggest that arriving earlier can be advantageous for bee‑eaters, as in years when breeding conditions are favourable, early and late breeders produce high and similar number of fledglings, but when conditions are unfavourable only early breeders experience high productivity levels.

Decreases in shorebird populations are increasingly evident worldwide, especially in the East Asian—Australasian Flyway (EAAF). To arrest these declines, it is important to understand the scale of both the problem and the solutions. We analysed an expansive Australian citizen-science dataset, spanning the period 1973 to 2014, to explore factors related to differences in trends among shorebird populations in wetlands throughout Australia. Of seven resident Australian shorebird species, the four inland species exhibited continental decreases, whereas the three coastal species did not. Decreases in inland resident shorebirds were related to changes in availability of water at non-tidal wetlands, suggesting that degradation of wetlands in Australia's interior is playing a role in these declines. For migratory shorebirds, the analyses revealed continental decreases in abundance in 12 of 19 species, and decreases in 17 of 19 in the southern half of Australia over the past 15 years. Many trends were strongly associated with continental gradients in latitude or longitude, suggesting some large-scale patterns in the decreases, with steeper declines often evident in southern Australia. After accounting for this effect, local variables did not explain variation in migratory shorebird trends between sites. Our results are consistent with other studies indicating that decreases in migratory shorebird populations in the EAAF are most likely being driven primarily by factors outside Australia. This reinforces the need for urgent overseas conservation actions. However, substantially heterogeneous trends within Australia, combined with declines of inland resident shorebirds indicate effective management of Australian shorebird habitat remains important.

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., + Publisher's Statement: "This is the peer reviewed version of the following article: Hahn, S., Alves, J.A., Bedev, K., Costa, J.S., Emmenegger, T., Schulze, M., Tamm, P., Zehtindjiev, P. and Dhanjal‐Adams, K.L. (2020), Range‐wide migration corridors and non‐breeding areas of a northward expanding Afro‐Palaearctic migrant, the European Bee‐eater Merops apiaster . Ibis, 162: 345-355", which has been published in final form at doi:10.1111/ibi.12752. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions."; Read Only Lizenz.