title: Sex-specific, inverted rhythms of breeding-site attendance in an Arctic seabird.
abstract: In contrast to daily rhythms that are common in the presence of the geophysical light-dark cycle, organisms at polar latitudes exhibit many diel activity patterns during natural periods of continuous solar light or darkness (polar day and night, respectively), from 24 h rhythms to arrhythmicity. In Arctic Greenland (73.7° N, 56.6° W) during polar day, we observed breeding-site attendance rhythms of thick-billed murres (Uria lomvia; n = 21 pairs), a charadriiform seabird, which provide biparental care at the colony. We found that U. lomvia egg-incubation and chick-brooding attendance is rhythmic and synchronized to the geophysical day (mean period length [rhythm duration] ± 95% confidence interval = 24.13 ± 0.52 h). Individual pair members had temporally segregated, sex-specific colony-attendance rhythms that were opposite (inverted) to each other, and these sex-specific rhythms were prominent at the population level. Our results provide a basis for investigating circadian systems at polar latitudes and sex-specific parental-care strategies.
authors.affiliation: Department of Biology, Wake Forest University, Winston-Salem, NC 27106, USA Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark huffnp13@wfu.edu.
authors.forename: Nicholas Per
authors.identifier: 0000-0002-0154-2536
authors.initials: NP
authors.lastname: Huffeldt
authors.affiliation: Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark Greenland Institute of Natural Resources, 3900 Nuuk, Greenland.
authors.forename: Flemming R
authors.initials: FR
authors.lastname: Merkel
mesh_terms: D000818:Animals; D001110:Arctic Regions; D046091:Charadriiformes / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006116:Greenland; D008027:Light; D008297:Male; D009425:Nesting Behavior / Q000502:physiology*; D012727:Sex Characteristics
keywords: Brünnich's guillemot; circadian rhythm; parental care; polar rhythm