Sex-specific, inverted rhythms of breeding-site attendance in an Arctic seabird

• Published in: Biology Letters
• Main Authors: Huffeldt, Nicholas Per, Merkel, Flemming R
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: Journal Article; Arctic; Greenland; Uria lomvia; uria
• Online Access: https://pure.au.dk/portal/da/publications/sexspecific-inverted-rhythms-of-breedingsite-attendance-in-an-arctic-seabird(63f90306-05a4-478a-8a88-a03687b3b499).html; https://doi.org/10.1098/rsbl.2016.0289; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5046920/pdf/rsbl20160289.pdf

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.