Case report: first data on the foraging behaviour of velvet scoters (Melanitta fusca) in soft-bottom coastal waters of the southeast Baltic Sea ...

• Main Authors: Forni, Paola, Morkunas, Julius, Daunys, Darius
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: figshare 2024
• Subjects: Ecology; FOS: Biological sciences; Melanitta fusca
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.6979874; https://springernature.figshare.com/collections/Case_report_first_data_on_the_foraging_behaviour_of_velvet_scoters_Melanitta_fusca_in_soft-bottom_coastal_waters_of_the_southeast_Baltic_Sea/6979874

Abstract Background The foraging behaviour of sea ducks has always been difficult to study due to their exclusive occupancy of coastal waters during the wintering season. In this study we investigated the foraging behaviour of seven wintering velvet scoters (Melanitta fusca) in Lithuanian soft-bottom coastal waters by attaching a solar-powered external GPS‐GSM transmitter to each individual bird. This transmitter data allowed us to analyse the dive phase parameters and feeding depths during December 2021 and March 2022. Results The results showed that velvet scoters dived deeper than a 30-m depth, with the dive duration lasting up to 90 s on average. The bottom duration increased rapidly in the first 5 m and then levelled off at around 40 s for deeper waters. The underwater duration varied between 2 and 7.5 h a day. The dive effort (as total underwater time) and the bottom duration of velvet scoters were related to the depth and prey biomass, although both factors were demonstrated to be interdependent. ...