Browsing by Author "Piironen, Antti"

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    Data from: Birds of three worlds: moult migration to high Arctic expands a boreal‑temperate flyway to a third biome
    (2021-11-15) Piironen, Antti; Paasivaara, Antti; Laaksonen, Toni
    Background: Knowledge on migration patterns and flyways is a key for understanding the dynamics of migratory populations and evolution of migratory behaviour. Bird migration is usually considered to be movements between breeding and wintering areas, while less attention has been paid to other long-distance movements such as moult migration. Methods: We use high-resolution satellite-tracking data from 58 taiga bean geese Anser fabalis fabalis from the years 2019–2020, to study their moult migration during breeding season. We show the moulting sites, estimate the migratory connectivity between the breeding and the moulting sites, and estimate the utilization distributions during moult. We reveal migration routes and compare the length and timing of migration between moult migrants and successful breeders. Results: All satellite-tracked non-breeding and unsuccessfully breeding taiga bean geese migrated annually to the island of Novaya Zemlya in the high Arctic for wing moult, meaning that a large part of the population gathers at the moulting sites outside the breeding range annually for approximately three months. Migratory connectivity between breeding and moulting sites was very low (rm =  − 0.001, 95% CI − 0.1562–0.2897), indicating that individuals from different breeding grounds mix with each other on the moulting sites. Moult migrants began fall migration later in autumn than successful breeders, and their overall annual migration distance was over twofold compared to the successful breeders. Conclusions: Regular moult migration makes the Arctic an equally relevant habitat for the taiga bean goose population as their boreal breeding and temperate wintering grounds, and links ecological communities in these biomes. Moult migration plays an important role in the movement patterns and spatio-temporal distribution of the population. Low migratory connectivity between breeding and moulting sites can potentially contribute to the gene flow within the population. Moult migration to the high Arctic exposes the population to the rapid impacts of global warming to Arctic ecosystems. Additionally, Novaya Zemlya holds radioactive contaminants from various sources, which might still pose a threat to moult migrants. Generally, these results show that moult migration may essentially contribute to the way we should consider bird migration and migratory flyways.
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    Data from: Effects of multiple targeted repelling measures on the behaviour of individually tracked birds in an area of increasing human-wildlife conflict
    (2022-09-29) Heim, Wieland; Piironen, Antti; Heim, Ramona Julia; Piha, Markus; Seimola, Tuomas; Forsman, Jukka T.; Laaksonen, Toni
    Some animal populations are rapidly increasing in numbers and expanding their ranges, leading to intensified human-wildlife conflicts. A wide range of tools has been developed to repel animals from areas where they are suspected to cause damage. For waterfowl, direct comparisons of multiple repelling methods have so far focused only on species´ presence, total numbers, cost effectiveness or subsequent damage assessments, but not on individual behaviour. Here, we investigated the individual responses of free-flying geese to three repelling methods using high-resolution tracking data. In an experimental setup, tracked individuals were repelled by human approach, gunshot sound or handheld lasers. We found that repelling success and return time to the field where the repelling took place increased when individuals were repelled multiple times. Travel distances after the repelling events were longer after human approach and gunshot sound compared to the handheld laser treatments. In spring, the probability to return to the same field was higher after repelling with handheld lasers, but no difference between treatments was evident in autumn. We observed no increase in the probability to visit accommodation fields, where geese were allowed to forage and were not repelled, after the repelling events. Synthesis and applications. We found no strong differences between the three methods regarding the repelling effectiveness and the resulting behaviour of the tracked geese. However, the higher return rates of individuals after repelling with handheld lasers in spring suggest that this method might be less effective in situations with bright sunlight or very large aggregations of geese. Apart from these limitations, we can recommend handheld lasers for repelling as they might reduce energetic losses for the geese and disturbance of non-target wildlife. Since repelling by gunshot sound and handheld lasers was twice as fast as repelling by human approach, those methods will reduce working hours by 50% and therefore be more cost-effective in practice.