Mates but not sexes differ in migratory niche in a monogamous penguin species

• Published in: Biology Letters
• Main Authors: Thiebot, Jean-Baptiste, Bost, Charles-André, Dehnhard, Nina, Demongin, Laurent, Eens, Marcel, Lepoint, Gilles, Cherel, Yves, Poisbleau, Maud
• Other Authors: MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society Publishing 2015
• Subjects: stable isotopes; geolocation; seabirds; subantarctica; monogamy; ethology; Life sciences; Zoology; Aquatic sciences & oceanology; Environmental sciences & ecology; Sciences du vivant; Zoologie; Sciences aquatiques & océanologie; Sciences de l’environnement & écologie; Rockhopper penguin
• Online Access: https://orbi.uliege.be/handle/2268/185854; https://orbi.uliege.be/bitstream/2268/185854/1/Thiebot%20et%20al%202015%20Rockhopper%20penguin%20mates%20-%20Biol%20Lett.pdf; https://doi.org/10.1098/rsbl.2015.0429

peer reviewed Strong pair bonds generally increase fitness in monogamous organisms, but may also underlie the risk of hampering it when re-pairing fails after the winter season. We investigated whether partners would either maintain contact or offset this risk by exploiting sex-specific favourable niches during winter in a migratory monogamous seabird, the southern rockhopper penguin Eudyptes chrysocome. Using light-based geolocation,we showthat although the spatial distribution of both sexes largely overlapped, pair-wise mates were located on average 595+260 km (and up to 2500 km) apart during winter. Stable isotope data also indicated a marked overlap between sex-specific isotopic niches (d13C and d15N values) but a segregation of the feeding habitats (d13C values) within pairs. Importantly, the tracked females remained longer (12 days) at sea than males, but all re-mated with their previous partners after winter. Our study provides multiple evidence that migratory species maywell demonstrate pair-wise segregation even in the absence of sex-specific winter niches (spatial and isotopic).We suggest that dispersive migration patterns with sex-biased timings may be a sufficient proximal cause for generating such a situation in migratory animals