Exposure to anthropogenic pollution is a growing threat to wildlife. In cooperation with researchers from the Khon Kaen University in Thailand, we now investigated exposure to metals in the crictically endangered Yellow-breasted Bunting, a small songbird that breeds in northern Eurasia and migrates via China to wintering sites in South-East Asia. We found very high levels of zinc (Zn) in feathers of birds captured in Thailand, and zinc levels were negatively linked to body condition. Follow-up studies now need to investigate whether the elevated Zn exposure in Yellow-breasted Buntings is linked to mining activities or to the recent increase in Zn-biofortified rice planted in Asia to combat human Zn deficiency.

Sankamethawee W, Keithmaleesatti S, Simla P, Heim W (2025) Bioaccumulation of metals in a critically endangered migratory songbird, the Yellow-breasted Bunting (Emberiza aureola). Environmental Toxicology and Chemistry: vgaf241 [https://doi.org/10.1093/etojnl/vgaf241]

On September 24, we tagged the first Yellow-browed warbler (Phylloscopus inornatus) on Helgoland in 2025 to track his migratory behaviour. How long will he stay on the island? When will he depart and in which direction? And will there be detections on the mainland? These are the questions we study using the Motus Wildlife Tracking System. Stay tuned for fascinating bird tracks!

This study compares migratory bird species that cross the Sahara (garden warbler, redstart, wheatear) with species that overwinter within Europe (robin, dunnock). Previous studies on Helgoland during autumn migration showed that trans-Saharan migrants are under greater time pressure in autumn, resulting in shorter stopobver and less dependency on weather conditions (Packmor et al. 2020 Mov Ecol). Until now, it was unclear whether this pattern also applies in spring, when the Sahara has already been crossed and all species cover a similar distance to their breeding grounds. The results confirm that trans-Saharan migrants exhibit the same time-optimised behaviour in spring, indicating that this strategy is probably genetically anchored and maintained until shortly before reaching the breeding area.

Klinner, T.*, Karwinkel, T.*, Packmor, F., & Schmaljohann, H. (2025). Stopover departure decisions in spring: pre-Saharan migrants stay longer and are more selective for favourable wind than trans-Saharan migrants. Movement Ecology, 13(1), 64. doi.org/10.1186/s40462-025-00575-0
*shared first authorship

Barn swallows are native to almost all continents and have developed different migration strategies. However, until now, nothing was known about the migration routes of the Siberian Barn Swallow, Hirundo rustica tytleri. Using geolocators and ring recoveries, a team led by Wieland Heim has now discovered that swallows from the Lake Baikal area overwinter in Southeast Asia. In doing so, they appear to choose a direct migration route, which differs from those of other Barn Swallow populations in Asia. The results were published in the Journal of Ornithology: https://doi.org/10.1007/s10336-025-02306-z
 

Anisimova V, Anisimov Y, Bastardot M, Beermann I, Kunz F, Heim W (2025) Geolocator tracking and ring recoveries reveal the migration of Siberian Barn Swallows Hirundo rustica tytleri. Journal of Ornithology https://doi.org/10.1007/s10336-025-02306-z