MEPS 546:263-269 (2016)  -  DOI: https://doi.org/10.3354/meps11669

ABSTRACT: We measured mercury concentration ([Hg]) and nitrogen stable isotope values (δ¹⁵N) in tail feathers that were replaced during the non-breeding period of streaked shearwaters Calonectris leucomelas that bred on 3 islands in Japan. The birds’ year-round movements were tracked and their breeding status was monitored. [Hg] was greater in males than in females, and was greatest in those birds spending their non-breeding period in the South China Sea (3.1 ± 1.5 µg g^-1 dry weight), moderate in birds in the Arafura Sea (1.5 ± 0.7 µg g^-1), and lowest in birds in the Pacific Ocean north of New Guinea (0.8 ± 0.4 µg g^-1). Adverse effects of feather [Hg] on breeding status were not observed. This regional variation in feather [Hg] might partly reflect differences in the intake of Hg between these non-breeding areas in addition to accumulation during the late breeding period and the southward migration period.

KEY WORDS: Geolocator · Migration · δ¹⁵N · Breeding