Complex Day-to-day Movements of an Alpine Passerine May Act as an Insurance Against Environmental Variability

Abstract

Mountains naturally offer very contrasting habitat conditions, but their biodiversity is nowadays facing the extra challenge of adapting to rapid environmental shifts that are much more pronounced than in the lowlands. Among the possible adaptive responses of wildlife, intra- and inter-seasonal movements represent an important coping strategy that remains largely unexplored. We investigated the seasonal and day-to-day movements of the ring ouzel Turdus torquatus, a European mountain bird species that is declining in many parts of its distribution. We tracked individuals breeding in the Swiss Alps using geolocators, multi-sensor loggers and GPS. Of the birds traced to their non-breeding quarters, two thirds reached the Atlas Mountains while one third stayed in Spain, a region potentially more significant for overwintering than previously thought. The birds remained mostly above 1000 m throughout the annual cycle, highlighting a strict association of ring ouzels with mountain habitats. We also evidenced flexible daily elevational movements, especially upon spring arrival on the breeding grounds, which suggest adaptive potential in response to environmental variation. This study shows how modern technology can deliver deeper insights into animal movements, paving the way for refined assessments of species vulnerability to ongoing global change while providing basic conservation guidance.

pamlr: a toolbox for analysing animal behaviour using pressure, acceleration, temperature, magnetic and light data in R

“…There are a number of other behaviours that are identifiable using multisensory geolocator tags. Though these tags have primarily been used on birds (Bäckman et al, 2017; Dhanjal-Adams et al, 2018; Liechti et al, 2018; Sjöberg et al, 2018; Briedis, Beran, Adamík, & Hahn, 2020; Evens et al, 2020; Barras, Arlettaz, & Liechti, 2021; Sander et al, 2021), they can also be used with bats (Voigt et al, 2020). There are therefore a number of behaviours that might be analysed from these tags.…”

“…The copyright holder for this preprint this version posted August 3, 2021. ; https://doi.org/10.1101/2021.08.02.454456 doi: bioRxiv preprint Though these tags have primarily been used on birds (Bäckman et al, 2017;Dhanjal-Adams et al, 2018;Liechti et al, 2018;Sjöberg et al, 2018;Briedis, Beran, Adamík, & Hahn, 2020;Evens et al, 2020;Barras, Arlettaz, & Liechti, 2021;Sander et al, 2021), they can also be used with bats (Voigt et al, 2020).…”