9 research outputs found
Duration of female parental care and their survival in the little auk Alle alle - are these two traits linked?
Desertion of offspring before its independence by one of the parents is observed in a number of avian species with bi-parental care but reasons for this strategy are not fully understood. This behaviour is particularly intriguing in species where bi-parental care is crucial to raise the brood successfully. Here, we focus on the little auk, Alle alle, a small seabird with intensive bi-parental care, where the female deserts the brood at the end of the chick rearing period. The little auk example is interesting as most hypotheses to explain desertion of the brood by females (e.g. âre-mating hypothesisâ, âbody condition hypothesisâ) have been rejected for this species. Here, we analysed a possible relationship between the duration of female parental care over the chick and her chances to survive to the next breeding season. We performed the study in two breeding colonies on Spitsbergen with different foraging conditions â more favourable in Hornsund and less favourable in Magdalenefjorden. We predicted that in Hornsund females would stay for shorter periods of time with the brood and would have higher survival rates in comparison with birds from Magdalenefjorden. We found that indeed in less favourable conditions of Magdalenefjorden, females stay longer with the brood than in the more favourable conditions of Hornsund. Moreover, female survival was negatively affected by the length of stay in the brood. Nevertheless, duration of female parental care over the chick was not related to their parental efforts, earlier in the chick rearing period, and survival of males and females was similar. Thus, although females brood desertion and winter survival are linked, the relationship is not straightforward
Pan-Arctic population of the keystone copepod Calanus glacialis
The copepod Calanus glacialis is endemic to the Arctic Ocean and peripheral seas and forms a key component of the Arctic marine ecosystems. It is the major contributor to zooplankton biomass, a predominant grazer, and an important prey for seabirds, and fish. As for a planktonic species, its dispersal is expected to be widespread and mediated by ocean currents. However, complex circulation patterns and the existence of semi-enclosed fjords and seas in the Arctic can be hypothesized to influence the population genetic structure of this species. In this study, we aimed to infer patterns of connectivity between populations of C. glacialis distributed around the Arctic and across putative barriers formed by oceanographic currents and semi-enclosed fjords and seas. To achieve this, we used 11 polymorphic microsatellite loci to genotype 189 individuals from 7 locations: Svalbard fjords (Kongsfjorden, Hornsund, Isfjorden, Rijpfjorden, and Storfjorden), White Sea, and Amundsen Gulf, thus providing greater genetic resolution over a larger biogeographical scale than in previous studies. The results revealed a lack of structure among all seven locations around the Arctic, indicating a panmictic population with large-scale gene flow. This study also supports the hypothesis that the planktonic fauna of the White Sea is not isolated from that of the other Arctic regions