Dias, M.P., Romero, J., Granadeiro, J.P., Catry, T., Pollet, I.L. & Catry, P. (2016) Distribution and at-sea activity of a nocturnal seabird, the Bulwer’s petrel Bulweria bulwerii, during the incubation period.
Deep-Sea Research Part I, 113, 49-56. DOI:10.1016/j.dsr.2016.03.006 (IF2016 2,480; Q1 Oceanography) NON-cE3c affiliatedBulwer's petrels are nocturnal seabirds that mostly prey on mesopelagic fauna. As aerial foragers and shallow divers, their feeding opportunities are limited by near-surface availability of their prey, which is highly variable both temporally (reflecting diurnal and lunar cycles) and spatially. Here we studied how Bulwer's petrels cope with these constraints by analysing their at-sea distribution and activity during the incubation period. We tracked the movements of 20 birds from Selvagem Grande (NE Atlantic) during a complete lunar cycle, and recorded 30 foraging trips that lasted 11 days on average. Birds were both distributed around the colony and in waters close to the Azorean archipelago (mid-Atlantic) located 1700 km away, and were significantly more active at night (especially just after sunset and before sunrise), when mesopelagic fauna is also closer to the sea surface due to their diel vertical migrations. Bulwer's petrels spent significantly more time flying during moonlight, although the effect of the moon was relatively weak (ca. 10–15% difference between moonlit and dark periods of the night), and not obvious when birds were foraging in mid-Atlantic waters, which were also targeted more often during full-moon. These results reveal key adaptations of the Bulwer's petrel to the highly dynamic ecology of its mesopelagic prey.
Maria Ana Dias Conservation in Socio-Ecological Systems - CSES
