![]() Contrastingly, increased trophic position but broader isotopic niche breadth during higher relative to lower Capelin availability for Leach’s Storm Petrel confirm that this species is likely not affected by the inshore arrival of Capelin, but instead that isotopic changes may be more related to a shift in breeding stage to chick‐rearing. Simultaneously, trophic diversity of the auk assemblage, reflecting the extent of spacing among niches of species, decreased after spawning Capelin arrived inshore. At the species level, auk trophic position increased, and isotopic niche breadth narrowed after Capelin arrived, suggesting a more Capelin‐based diet. We quantified stable isotope ratios (δ15N, δ13C) in seabird blood components (plasma, cellular component) collected both before and after spawning Capelin arrived in the study area and compared isotopic niche breadth within a Bayesian framework. The diet of Leach’s Storm Petrels (Oceanodroma leucorhoa), that breed alongside the three auk species but are not known to rely on Capelin, was also examined to determine dietary shifts throughout breeding that were unrelated to Capelin availability. During June‐August 2017, we investigated species‐ and assemblage‐level dietary responses to shifting Capelin availability of three Capelin‐eating, sympatrically breeding auk species, the Atlantic Puffin (Fratercula arctica), Razorbill (Alca torda), Common Murre (Uria aalge). On the Newfoundland coast, annual inshore spawning migration of the dominant forage fish, Capelin (Mallotus villosus), provides an excellent opportunity to investigate the influence of varying prey availability on dietary niche breadth and position among species. Shifting prey availability can lead to altered species interactions, indicated by variation in the dietary niche breadth and position of species within an assemblage. Given the Atlantic Puffin’s deteriorating conservation status, improved information on seasonal changes in body condition should help determine the underlying causes of die-offs in major wreck incidents such as those reported in recent years. ![]() They indicate that gains in body mass between chick-rearing and winter are at least double the decline in mass previously recorded between incubation and chick-rearing. ![]() The very limited individual level data accorded well with the population level estimates.Ĭonclusions: Our results provide the first estimates of the order of magnitude in mass change between two key life history stages in this species. Results: On average, Atlantic Puffins breeding in Scotland and Norway increased their body mass by 20–30% between the chick-rearing period and winter. In three cases data were available for individuals weighed both at the colony and on the wintering grounds. These measurements were used to estimate seasonal changes in body mass for the two breeding populations. Methods: We took standardized measurements of wing length and body mass of Atlantic Puffins during the summer chick-rearing period and on the wintering grounds near the Faroe Islands. garinii circulating within seabird tick-avian host transmission cycles could directly, or indirectly via connectivity with terrestrial transmission cycles, have consequences for human health.Ĭapsule: Atlantic Puffins Fratercula arctica from Scottish and Norwegian populations were significantly heavier in winter than when rearing chicks.Īims: To compare body masses of Atlantic Puffins on their wintering grounds off the Faroe Islands with those of birds rearing chicks at colonies in Scotland and Norway. garinii from seabird ticks and humans indicate the possibility that B. garinii in this ecosystem and terrestrial sources in Eurasia. garinii circulating among seabird ticks and their avian hosts but also demonstrate surprisingly close connections between B. Our findings highlight the genetic complexity of B. This revealed new MLST sequence types and alleles, enhancing our knowledge of B. garinii sequences from North American seabird ticks that were characterized using an MLST approach. Some were very similar to strains from Asia and Europe, including some obtained from human clinical samples, while others formed a divergent group specific to this region of the Atlantic Ocean. garinii strains found in this seabird colony ecosystem were diverse. garinii found in ticks from four species of seabirds. We applied a multi-locus sequence typing (MLST) scheme to B. uriae collected from seabird colonies in the northwestern Atlantic Ocean, in Newfoundland and Labrador, Canada. Research on the population structure of this bacterium in ticks from seabird colonies in the northeastern Atlantic Ocean has revealed admixture between marine and terrestrial tick populations. The occurrence of Borrelia garinii in seabird ticks, Ixodes uriae, associated with different species of colonial seabirds has been studied since the early 1990s.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |