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Sarah Wanless - One of the best experts on this subject based on the ideXlab platform.
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Protracted treatment with corticosterone reduces breeding success in a long-lived bird.
General and Comparative Endocrinology, 2015Co-Authors: Bethany F. Nelson, Pat Monaghan, Adam Butler, Britt J. Heidinger, Mark A. Newell, Francis Daunt, Sarah Wanless, Alistair DawsonAbstract:Determining the physiological mechanisms underpinning life-history decisions is essential for understanding the constraints under which life-history strategies can evolve. In long-lived species, where the residual reproductive value of breeders is high, adult survival is a key contributor to lifetime reproductive success. We therefore expect that when adult survival is compromised during reproduction, mechanisms will evolve to redirect resources away from reproduction, with implications for reproductive hormones, adult body mass, nest attendance behaviour and breeding success. We investigated whether manipulating corticosterone, to simulate exposure to an environmental stressor, affected the secretion of prolactin and breeding success in the Black-Legged Kittiwake Rissa tridactyla. We used implanted Alzet® osmotic pumps to administer corticosterone to incubating Kittiwakes at a constant rate over a period of approximately 8 days. Manipulated birds were compared with sham implanted birds and control birds, which had no implants. There was no significant difference in the body mass of captured individuals at the time of implantation and implant removal. Corticosterone-implanted males showed lower nest attendance during the chick rearing period compared to sham-implanted males; the opposite pattern was found in females. Corticosterone treated birds showed a marginally significant reduction in breeding success compared to sham-implanted individuals, with all failures occurring at least 1 week after implant removal. However, prolactin concentrations at implant removal were not significantly different from initial values. We were unable to measure the profile of change in corticosterone during the experiment. However, our results suggest a delayed effect of elevated corticosterone on breeding success rather than an immediate suppression of prolactin concentrations causing premature failure.
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Climate, copepods and seabirds in the boreal Northeast Atlantic - current state and future outlook
Global Change Biology, 2013Co-Authors: Morten Frederiksen, Grégory Beaugrand, Tycho Anker-nilssen, Sarah WanlessAbstract:The boreal Northeast Atlantic is strongly affected by current climate change, and large shifts in abundance and distribution of many organisms have been observed, including the dominant copepod Calanus finmarchicus, which supports the grazing food web and thus many fish populations. At the same time, large-scale declines have been observed in many piscivorous seabirds, which depend on abundant small pelagic fish. Here, we combine predictions from a niche model of C. finmarchicus with long-term data on seabird breeding success to link trophic levels. The niche model shows that environmental suitability for C. finmarchicus has declined in southern areas with large breeding seabird populations (e.g. the North Sea), and predicts that this decline is likely to spread northwards during the 21st century to affect populations in Iceland and the Faroes. In a North Sea colony, breeding success of three common piscivorous seabird species [Black-Legged Kittiwake (Rissa tridactyla), common guillemot (Uria aalge) and Atlantic puffin (Fratercula arctica)] was strongly positively correlated with local environmental suitability for C. finmarchicus, whereas this was not the case at a more northerly colony in west Norway. Large seabird populations seem only to occur where C. finmarchicus is abundant, and northward distributional shifts of common boreal seabirds are therefore expected over the coming decades. Whether or not population size can be maintained depends on the dispersal ability and inclination of these colonial breeders, and on the carrying capacity of more northerly areas in a warmer climate.
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seasonal interactions in the black legged Kittiwake rissa tridactyla links between breeding performance and winter distribution
Proceedings of The Royal Society B: Biological Sciences, 2011Co-Authors: Maria I Bogdanova, Mark A. Newell, Francis Daunt, Richard A Phillips, M P Harris, Sarah WanlessAbstract:Relationships between events in one period of the annual cycle and behaviour in subsequent seasons are key determinants of individual life histories and population dynamics. However, studying such associations is challenging, given the difficulties in following individuals across seasons, particularly in migratory species. Relationships between breeding performance and subsequent winter ecology are particularly poorly understood, yet are likely to be profoundly important because of the costs of reproduction. Using geolocation technology, we show that Black-Legged Kittiwakes that experienced breeding failure left their colony in southeast Scotland earlier than successful breeders. Moreover, a greater proportion of unsuccessful breeders (94% versus 53% successful) travelled over 3000 km to the West Atlantic, whereas fewer visited the East Atlantic (31% versus 80% successful), less than 1000 km from the colony. The two groups did not differ in the timing of return to the colony the following spring. However, 58 per cent of males made a previously undescribed long-distance pre-breeding movement to the central Atlantic. Our results demonstrate important links between reproductive performance and winter distribution, with significant implications for population dynamics. Furthermore, macro-scale segregation associated with breeding outcome is relevant to defining important wintering areas, in particular among declining species experiencing increasingly regular breeding failure.
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Scale-dependent climate signals drive breeding phenology of three seabird species
Global Change Biology, 2004Co-Authors: Morten Frederiksen, Francis Daunt, M P Harris, P Rothery, Sarah WanlessAbstract:Breeding at the right time is essential for animals in seasonal climates in order to ensure that the energy demands of reproduction, particularly the nutritional requirements of growing young, coincide with peak food availability. Global climate change is likely to cause shifts in the timing of peak food availability, and in order to adapt successfully to current and future climate change, animals need to be able to adjust the time at which they initiate breeding. Many animals use environmental cues available before the breeding season to predict the seasonal peak in food availability and adjust their phenology accordingly. We tested the hypothesis that regulation of breeding onset should reflect the scale at which organisms perceive their environment by comparing phenology of three seabird species at a North Sea colony. As predicted, the phenology of two dispersive species, Black-Legged Kittiwake (Rissa tridactyla) and common guillemot (Uria aalge), correlated with a large-scale environmental cue (the North Atlantic Oscillation), whereas a resident species, European shag (Phalacrocorax aristotelis), was more affected by local conditions (sea surface temperature) around the colony. Annual mean breeding success was lower in late years for European shags, but not for the other two species. Since correlations among climate patterns at different scales are likely to change in the future, these findings have important implications for how migratory animals can respond to future climate change.
Descamps Sébastien - One of the best experts on this subject based on the ideXlab platform.
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Relationships between isotopic ratios, body condition and breeding success in a High Arctic seabird community
'Inter-Research Science Center', 2024Co-Authors: Hovinen, Johanna E.h., Tarroux Arnaud, Ramírez Benítez, Francisco José, González Forero Manuela, Descamps SébastienAbstract:Predators such as seabirds are often used as bio-indicators of the marine environment. This is based on the assumption that changes in seabird populations are driven by changes in their prey. We tested this assumption in a High Arctic seabird community by assessing the relationships between the diet, body condition, and breeding performance of 4 ecologically different species: the little auk Alle alle, Black-Legged Kittiwake Rissa tridactyla, Brünnich's guillemot Uria lomvia, and glaucous gull Larus hyperboreus, breeding in Svalbard, Norway. Interannual changes in seabird diet (2009-2015) were assessed by estimating their carbon and nitrogen isotopic ratios (δ15N and δ13C) during the breeding and non-breeding seasons (i.e. using blood and feather tissues). We found interannual variation in the isotopic ratios during both seasons in all 4 species. These variations differed among species, thus suggesting dietary changes, instead of changes in isotopic baselines, as the most plausible mechanism underlying such patterns. We also found that seabirds had a lower average hatching success when the average δ15N during the previous non-breeding season was higher. Our results suggest that changes in the average prey composition during the non-breeding season may partially explain changes in breeding performance of Svalbard seabirds
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Relationships between isotopic ratios, body condition and breeding success in a High Arctic seabird community
'Inter-Research Science Center', 2019Co-Authors: Hovinen, Johanna Emilia Heidi, Tarroux Arnaud, Ramirez Francisco, Forero Manuela, Descamps SébastienAbstract:Predators such as seabirds are often used as bio-indicators of the marine environment. This is based on the assumption that changes in seabird populations are driven by changes in their prey. We tested this assumption in a High Arctic seabird community by assessing the relationships between the diet, body condition, and breeding performance of 4 ecologically different species: the little auk Alle alle, Black-Legged Kittiwake Rissa tridactyla, Brünnich’s guillemot Uria lomvia, and glaucous gull Larus hyperboreus, breeding in Svalbard, Norway. Interannual changes in seabird diet (2009−2015) were assessed by estimating their carbon and nitrogen isotopic ratios (δ15N and δ13C) during the breeding and non-breeding seasons (i.e. using blood and feather tissues). We found interannual variation in the isotopic ratios during both seasons in all 4 species. These variations differed among species, thus suggesting dietary changes, instead of changes in isotopic baselines, as the most plausible mechanism underlying such patterns. We also found that seabirds had a lower average hatching success when the average δ15N during the previous nonbreeding season was higher. Our results suggest that changes in the average prey composition during the non-breeding season may partially explain changes in breeding performance of Svalbard seabirds.acceptedVersio
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Multi-colony tracking reveals spatio-temporal variation in carry-over effects between breeding success and winter movements in a pelagic seabird
'Inter-Research Science Center', 2017Co-Authors: Bogdanova Maria, Anker-nilssen Tycho, Christensen-dalsgaard Signe, Moe Børge, Boulinier Thierry, Wanless Sarah, Frederiksen Morten, Butler Adam, Chivers, Lorraine S., Descamps SébastienAbstract:Carry-over effects, whereby events in one season have consequences in subsequent seasons, have important demographic implications. Although most studies examine carry-over effects across 2 seasons in single populations, the effects may persist beyond the following season and vary across a species’ range. To assess potential carry-over effects across the annual cycle and among populations, we deployed geolocation loggers on Black-Legged Kittiwakes Rissa tridactyla at 10 colonies in the north-east Atlantic and examined relationships between the timing and destination of migratory movements and breeding success in the year of deployment and sub - sequent season. Both successful and unsuccessful breeders wintered primarily in the north-west Atlantic. Breeding success affected the timing of migration, whereby unsuccessful breeders departed the colony earlier, arrived at the post-breeding and main wintering areas sooner, and departed later the following spring. However, these patterns were only apparent in colonies in the south-west of the study region. Furthermore, the effect of breeding success was stronger on migration timing in the first part of the winter than later. Timing of migratory movements was weakly linked to subsequent breeding success, and there was no detectable association between breeding success in the 2 seasons. Our results indicate temporal structure and spatial hetero - geneity in the strength of seasonal interactions among Kittiwakes breeding in the north-east Atlantic. Variable fitness consequences for individuals from different colonies could have important implications for population processes across the species’ range and suggest that the spatiotemporal dynamics of carry-over effects warrant further study. Seasonal interactions · Migration · Reproduction · Life-history strategies · Geolocation · Black-Legged Kittiwake · Rissa tridactyla · North AtlanticpublishedVersio
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Later at higher latitudes: large-scale variability in seabird breeding timing and synchronicity
'Wiley', 2016Co-Authors: Burr, Zofia M., Varpe Øystein, Anker-nilssen Tycho, Erikstad, Kjell E, Descamps Sébastien, Barrett, Robert T, Bech Claus, Christensen-dalsgaard Signe, Lorentsen Svein-håkon, Moe BørgeAbstract:Publisher's version, source: http://doi.org/10.1002/ecs2.1283.In seasonal environments, organisms are expected to optimally schedule reproduction within an annual range of environmental conditions. Latitudinal gradients generate a range of seasonality to which we can expect adaptations to have evolved, and can be used to explore drivers of timing strategies across species’ distribution ranges. This study compares the timing of egg hatching in four seabird species (Atlantic puffin Fratercula arctica, Black-Legged Kittiwake Rissa tridactyla, common guillemot Uria aalge, and Brünnich's guillemot U. lomvia) covering a subarctic to Arctic latitudinal gradient along the Norwegian coast to Svalbard (65–79°N). Hatching was significantly delayed by an estimated 1.7, 2.3, and 1.9 d per latitudinal degree for puffins, Kittiwakes, and common guillemots, respectively, but was not delayed for Brünnich's guillemots. Hatching distributions revealed an increase in intra-annual breeding synchronicity along a latitudinal gradient for Kittiwakes only, whereas the two guillemots exhibited high hatching synchronicity at all colonies. We used this large-scale, multispecies timing data series to discuss constraints, adaptations, and mechanisms affecting breeding timing, a necessary step to recognize risks to populations and predict future ecosystem change
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Later at higher latitudes: large-scale variability in seabird breeding timing and synchronicity
'Wiley', 2016Co-Authors: Burr, Zofia M., Varpe Øystein, Anker-nilssen Tycho, Erikstad, Kjell E, Descamps Sébastien, Barrett, Robert T, Bech Claus, Christensen-dalsgaard Signe, Lorentsen Svein-håkon, Moe BørgeAbstract:In seasonal environments, organisms are expected to optimally schedule reproduction within an annual range of environmental conditions. Latitudinal gradients generate a range of seasonality to which we can expect adaptations to have evolved, and can be used to explore drivers of timing strategies across species’ distribution ranges. This study compares the timing of egg hatching in four seabird species (Atlantic puffin Fratercula arctica, Black-Legged Kittiwake Rissa tridactyla, common guillemot Uria aalge, and Brünnich’s guillemot U. lomvia) covering a subarctic to Arctic latitudinal gradient along the Norwegian coast to Svalbard (65–79°N). Hatching was significantly delayed by an estimated 1.7, 2.3, and 1.9 d per latitudinal degree for puffins, Kittiwakes, and common guillemots, respectively, but was not delayed for Brünnich’s guillemots. Hatching distributions revealed an increase in intra-annual breeding synchronicity along a latitudinal gradient for Kittiwakes only, whereas the two guillemots exhibited high hatching synchronicity at all colonies. We used this large-scale, multispecies timing data series to discuss constraints, adaptations, and mechanisms affecting breeding timing, a necessary step to recognize risks to populations and predict future ecosystem change. Arctic; Fratercula arctica; hatching timing; inter-annual variability; Rissa tridactyla; seasonality; spatial phenology; Uria aalge; Uria lomvia. Receive
Ton G. G. Groothuis - One of the best experts on this subject based on the ideXlab platform.
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Testosterone increases siblicidal aggression in Black-Legged Kittiwake chicks (Rissa tridactyla)
Behavioral Ecology and Sociobiology, 2014Co-Authors: Martina S. Müller, Børge Moe, Ton G. G. GroothuisAbstract:To compete for parental food deliveries nestling birds have evolved diverse behaviors such as begging displays and sibling aggression. Testosterone has been suggested to be an important mechanism orchestrating such competitive behaviors, but evidence is scarce and often indirect. Siblicidal species provide an interesting case in which a clear dominance hierarchy is established and the dominant chicks lethally attack siblings. We experimentally elevated testosterone in chicks of a facultatively siblicidal species, the Black-Legged Kittiwake, Rissa tridactyla , and showed that testosterone-treated chicks were more aggressive toward their sibling than were control chicks. In such facultatively siblicidal species, chicks normally exhibit intense aggression only when threatened by starvation. Indeed, we found that chicks in relatively poorer condition were more aggressive than were chicks in better condition, even among testosterone-treated chicks, suggesting the action of an additional signal modulating aggression. Relatively larger siblings were also more aggressive than were relatively smaller siblings, confirming the importance of size advantage in determining dominance hierarchies within the brood. In addition, testosterone increased aggression toward a simulated predator, indicating that in Kittiwakes testosterone can increase aggression in contexts other than siblicide. Testosterone promoted aggression-mediated dominance, which increased begging although testosterone treatment did not have a significant separate effect on begging. Therefore, testosterone production in the Kittiwake and most likely other siblicidal species seems an important fitness mediator already early in life, outside the sexual context and not only manifesting itself in aggressive behavior but also in dominance-mediated effects on food solicitation displays toward parents.
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maternal androgens increase sibling aggression dominance and competitive ability in the siblicidal black legged Kittiwake rissa tridactyla
PLOS ONE, 2012Co-Authors: Martina S. Müller, Kjell Einar Erikstad, Yvonne Roelofs, Ton G. G. GroothuisAbstract:Animals and plants routinely produce more offspring than they can afford to rear. Mothers can favour certain young by conferring on them competitive advantages such as a leading position in the birth sequence, more resources or hormones. Avian mothers create hatching asynchrony within a clutch and at the same time bestow the eggs with different concentrations of androgens that may enhance or counteract the competitive advantage experienced by early-hatching ‘‘core’’ young. In siblicidal birds, core young assume a dominant social position in the nest due to their size advantage and when threatened with starvation fatally attack subdominant later-hatching ‘‘marginal’’ young. A role for maternal androgens in siblicidal aggression has frequently been suggested but never tested. We studied this in the facultatively siblicidal blackheaded Kittiwake. We found that marginal eggs contain higher instead of lower concentrations of androgens than core eggs. Surprisingly, exposure to experimentally elevated yolk androgens increased sibling aggression and dominance, even though in nature marginal eggs never produce dominant chicks. We propose the ‘‘adoption facilitation hypothesis’’ to explain this paradox. This cliff-nesting colonial species has a high adoption rate: ejected marginal Kittiwake chicks frequently fall into other nests containing chicks of similar or smaller size and exposure to yolk androgens might help them integrate themselves into a foster nest.
Barrett, Robert T - One of the best experts on this subject based on the ideXlab platform.
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Prevailing weather conditions and dietcomposition affect chick growth and survival in the Black-Legged Kittiwake
'Inter-Research Science Center', 2018Co-Authors: Christensen-dalsgaard Signe, Barrett, Robert T, Langset Magdalene, May, Roel F., Sandercock, Brett K., Lorentsen Svein-håkonAbstract:Source at https://doi.org/10.3354/meps12744 .To identify priorities for management of seabirds during the breeding season, it is important to understand the ecological mechanisms driving chick growth and survival. In this study, we examined the effects of diet and prevailing weather on the growth and survival of chicks of Black-Legged Kittiwakes Rissa tridactyla over a 10 yr period at Anda, a seabird colony in northern Norway. We show that across all years, there was a significant effect of diet composition delivered to chicks on their growth and survival. A higher proportion of sandeel Ammodytes spp. in the chick diet was associated with an increase in daily growth rates, a pattern that was especially pronounced for the youngest chick in 2-chick broods. A high proportion of mesopelagic fish in the chick diet was associated with a decrease in survival, again, especially for the youngest chick in 2-chick broods. Periods of strong southerly winds also led to reduced survival, probably linked to nests being washed down from the colony. Growth rates of Kittiwake chicks were negatively affected by wind speed, likely due to adults having to work more in the exposed habitats in strong winds, causing a reduction in the amount of food supplied to the chicks. Our results emphasise the importance of conservation of specific marine habitats shown to be important foraging areas in ensuring the reproductive success of seabirds. This might prove increasingly important if future climate regimes make ecological conditions more challenging for seabirds
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Prevailing weather conditions and diet composition affect chick growth and survival in the Black-Legged Kittiwake
'Inter-Research Science Center', 2018Co-Authors: Christensen-dalsgaard Signe, Barrett, Robert T, Langset Magdalene, May, Roel F., Sandercock, Brett K., Lorentsen Svein-håkonAbstract:To identify priorities for management of seabirds during the breeding season, it is important to understand the ecological mechanisms driving chick growth and survival. In this study, we examined the effects of diet and prevailing weather on the growth and survival of chicks of Black-Legged Kittiwakes Rissa tridactyla over a 10 yr period at Anda, a seabird colony in northern Norway. We show that across all years, there was a significant effect of diet composition delivered to chicks on their growth and survival. A higher proportion of sandeel Ammodytes spp. in the chick diet was associated with an increase in daily growth rates, a pattern that was especially pronounced for the youngest chick in 2-chick broods. A high proportion of mesopelagic fish in the chick diet was associated with a decrease in survival, again, especially for the youngest chick in 2-chick broods. Periods of strong southerly winds also led to reduced survival, probably linked to nests being washed down from the colony. Growth rates of Kittiwake chicks were negatively affected by wind speed, likely due to adults having to work more in the exposed habitats in strong winds, causing a reduction in the amount of food supplied to the chicks. Our results emphasise the importance of conservation of specific marine habitats shown to be important foraging areas in ensuring the reproductive success of seabirds. This might prove increasingly important if future climate regimes make ecological conditions more challenging for seabirds
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Ocean climate and egg investment in the Black-Legged Kittiwake Rissa tridactyla
'Inter-Research Science Center', 2017Co-Authors: Barrett, Robert T, Erikstad, Kjell E, Reiertsen ToneAbstract:Birds allocate substantial resources to their eggs during the laying period, resources also needed for other concurrent costly processes such as mate acquisition, nest building and site defence. Egg and clutch sizes may thus vary in response to food availability prior to egg laying. We investigated the variation in egg and clutch size of Black-Legged Kittiwakes Rissa tridactyla in a North Norwegian colony over a 33 yr period (1980–2012). Considerable interannual variation was evident in both egg and clutch sizes, but no temporal trends were observed. To identify environmental conditions explaining the variation, we modelled egg size and number in relation to the influx of warm Atlantic Water (AW) into the Barents Sea and to the abundance of 2 of the Kittiwakes’ most preferred prey species. Most of the variation was explained by the volumes of AW that flowed into the Barents Sea in winter and autumn. Both had a negative effect on egg investment. There was also a smaller, positive effect on egg investment of AW inflow (and capelin numbers for clutch size) immediately prior to egg laying. The negative impact of an increased influx of AW on Kittiwakes may be partly due to the resulting warming of the waters, forcing a more northerly distribution of capelin beyond the foraging range of the Kittiwakes at the colony or to changes at different trophic levels that are detrimental to Kittiwake forage fish ecology. A further warming of the Barents Sea through climate change is thus forecast to be detrimental for Kittiwakes. Egg volume · Clutch size · Black-Legged Kittiwake · Rissa tridactyla · Ocean climateacceptedVersio
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Ocean climate and egg investment in the Black-Legged Kittiwake Rissa tridactyla.
'Inter-Research Science Center', 2017Co-Authors: Barrett, Robert T, Erikstad, Kjell E, Reiertsen ToneAbstract:Published version available in Marine Ecology Progress Series 2017, 579: 129–137. Birds allocate substantial resources to their eggs during the laying period, resources also needed for other concurrent costly processes such as mate acquisition, nest building and site defence. Egg and clutch sizes may thus vary in response to food availability prior to egg laying. We investigated the variation in egg and clutch size of Black-Legged Kittiwakes Rissa tridactyla in a North Norwegian colony over a 33 yr period (1980–2012). Considerable interannual variation was evident in both egg and clutch sizes, but no temporal trends were observed. To identify environmental conditions explaining the variation, we modelled egg size and number in relation to the influx of warm Atlantic Water (AW) into the Barents Sea and to the abundance of 2 of the Kittiwakes’ most preferred prey species. Most of the variation was explained by the volumes of AW that flowed into the Barents Sea in winter and autumn. Both had a negative effect on egg investment. There was also a smaller, positive effect on egg investment of AW inflow (and capelin numbers for clutch size) immediately prior to egg laying. The negative impact of an increased influx of AW on Kittiwakes may be partly due to the resulting warming of the waters, forcing a more northerly distribution of capelin beyond the foraging range of the Kittiwakes at the colony or to changes at different trophic levels that are detrimental to Kittiwake forage fish ecology. A further warming of the Barents Sea through climate change is thus forecast to be detrimental for Kittiwakes. Egg volume · Clutch size · Black-Legged Kittiwake · Rissa tridactyla · Ocean climat
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Ocean climate and egg investment in the Black-Legged Kittiwake Rissa tridactyla.
Inter Research, 2017Co-Authors: Barrett, Robert T, Erikstad, Kjell E, Reiertsen ToneAbstract:Birds allocate substantial resources to their eggs during the laying period, resources also needed for other concurrent costly processes such as mate acquisition, nest building and site defence. Egg and clutch sizes may thus vary in response to food availability prior to egg laying. We investigated the variation in egg and clutch size of Black-Legged Kittiwakes Rissa tridactyla in a North Norwegian colony over a 33 yr period (1980–2012). Considerable interannual variation was evident in both egg and clutch sizes, but no temporal trends were observed. To identify environmental conditions explaining the variation, we modelled egg size and number in relation to the influx of warm Atlantic Water (AW) into the Barents Sea and to the abundance of 2 of the Kittiwakes’ most preferred prey species. Most of the variation was explained by the volumes of AW that flowed into the Barents Sea in winter and autumn. Both had a negative effect on egg investment. There was also a smaller, positive effect on egg investment of AW inflow (and capelin numbers for clutch size) immediately prior to egg laying. The negative impact of an increased influx of AW on Kittiwakes may be partly due to the resulting warming of the waters, forcing a more northerly distribution of capelin beyond the foraging range of the Kittiwakes at the colony or to changes at different trophic levels that are detrimental to Kittiwake forage fish ecology. A further warming of the Barents Sea through climate change is thus forecast to be detrimental for Kittiwakes. Egg volume · Clutch size · Black-Legged Kittiwake · Rissa tridactyla · Ocean climat
Derek C G Muir - One of the best experts on this subject based on the ideXlab platform.
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occurrence of substituted diphenylamine antioxidants and benzotriazole uv stabilizers in arctic seabirds and seals
Science of The Total Environment, 2019Co-Authors: Amila O De Silva, Birgit M. Braune, Jennifer F Provencher, Mark L Mallory, Jane L Kirk, Magali Houde, Connor Stewart, Stephanie Averygomm, Derek C G MuirAbstract:Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are contaminants of emerging environmental concern. However, little is known about the occurrence of these contaminants in the Arctic. In this study, we investigated the levels of 11 SDPAs and 6 BZT-UVs in livers and eggs of two seabird species, the Black-Legged Kittiwake (Rissa tridactyla) and northern fulmar (Fulmarus glacialis), as well as the liver of ringed seals (Pusa hispida) from Canadian high- and sub-Arctic sites. The concentrations of ΣSDPAs in seabird livers (median 336 pg g, wet weight (ww)) were significantly higher than the eggs (median 24 pg g, ww) and the seal livers (median 38 pg g, ww), suggesting liver was a primary tissue of SDPA accumulation in seabirds and that seabirds were at greater risk of exposure to SDPAs than marine mammals in the Arctic. The predominant SDPA was monostyryl octyl-diphenylamine and this compound was detected in every seabird and seal sample, indicating the widespread distribution of this contaminant in Arctic food webs. Unlike SDPAs, the detection rate and concentrations of BZT-UVs in seals were higher than in seabirds. The compound 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (UV329) or its isomer 2-(2H-benzotriazol-2-yl)-4-(tert-butyl)-6-(sec-butyl) phenol (UV350) was the predominant BZT-UVs in seals, with the concentrations of ΣBZT-UVs between
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bioaccumulation of pcbs in arctic seabirds influence of dietary exposure and congener biotransformation
Environmental Pollution, 2005Co-Authors: Katrine Borga, Janneche Utne Skaare, Hans Wolkers, Haakon Hop, Derek C G Muir, Geir Wing GabrielsenAbstract:Abstract Four seabird species and their prey (zooplankton or fish) were collected in the Barents Sea to determine how dietary exposure, cytochrome P450 (CYP) enzyme activities and sex influenced their hepatic PCB concentrations and accumulation patterns. Five males and five females from each seabird species (little auk ( Alle alle ), Brunnich's guillemot ( Uria lomvia ), black guillemot ( Cepphus grylle ) and Black-Legged Kittiwake ( Rissa tridactyla )) were analysed. PCB concentrations could not be explained directly by carbon source ( δ 13 C) or trophic position ( δ 15 N), but by a combination of dietary parameters ( δ 13 C, δ 15 N, migratory pattern, age) and contaminant metabolism. Contrary to previous studies, the PCB pattern differed among seabirds, with a higher proportion of persistent congeners (% of PCB-153, R PCB-153 ) in Black-Legged Kittiwake than in auks. The PCB pattern also differed among auks, with little auk as the most efficient biotransformer (highest R PCB-153 values of persistent congeners). Based on high R PCB-153 values, Brunnich's guillemot poorly metabolised ortho – meta -unsubstituted congeners, whereas black guillemot poorly metabolised meta – para unsubstituted congeners. Species-specific differences in PCB biotransformation were confirmed by metabolic indices, where PCB patterns in seabirds were adjusted for PCB pattern in prey. The relative contribution of ortho – meta -unsubstituted congeners to ∑PCBsdecreased with increasing EROD activity. There were no differences in PCB concentrations, PCB patterns or cytochrome P450 enzyme activities between males and females. CYP P450 activities (CYP1A- and CYP2B/3A-like: EROD and testosterone 6β-hydroxylation, respectively) were low and did not correlate with concentrations of non- or mono- ortho Cl-substituted PCBs (NO- and MO-PCBs), or with total toxic equivalent concentrations (TEQs) for dioxin-like effects of NO- and MO-PCBs.