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Anthony J. Gaston - One of the best experts on this subject based on the ideXlab platform.
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A First Count of Thick-billed Murres ( Uria lomvia ) and Black-legged Kittiwakes ( Rissa tridactyla ) Breeding on Bylot Island
The Canadian Field-Naturalist, 2017Co-Authors: Anthony J. Gaston, Marc-andre Cyr, Kieran O'dononvanAbstract:Bylot Island, part of Sirmilik National Park, supports two major breeding colonies of intermingled Thick-billed Murres ( Uria lomvia ) and Black-legged Kittiwakes ( Rissa tridactyla ): at Cape Hay near the northwest tip and at Cape Graham Moore at the opposite end of the island. Although the size of these colonies has been estimated previously, there is no information on how the estimates were made, except for Thick-billed Murres at Cape Hay in 1977, when the numbers were based on sampling only about 30% of the colony. In 2013, high-resolution digital photographs of the whole area of both colonies were taken in July, when most birds were probably incubating eggs. Individual birds were counted on the photographs, and the numbers were corrected for image quality and converted to numbers of breeding pairs based on correction factors from another High Arctic colony. Our estimates were similar to those from earlier years for kittiwakes at Cape Graham Moore and for murres at Cape Hay, but suggested that numbers of murres were higher than previously thought at Cape Graham Moore, while numbers of kittiwakes were lower at Cape Hay. The overall total for the Canadian population of Thick-billed Murres was unaffected by these changes, but the total number of Black-legged Kittiwakes nesting in the Canadian Arctic may be 20% lower than previously thought.
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migration and wintering of a declining seabird the thick billed murre Uria lomvia on an ocean basin scale conservation implications
Biological Conservation, 2016Co-Authors: Morten Frederiksen, Anthony J. Gaston, Grant H Gilchrist, Sebastien Descamps, Kjell Einar Erikstad, David Gremillet, Kasper Lambert Johansen, Yann Kolbeinsson, Jannie F LinnebjergAbstract:Pelagic seabirds are exposed to an array of potential threats during the non-breeding period, and effective management of these threats on a large scale requires knowledge of which populations winter where. Thick-billed murres (Uria lomvia) are emblematic of this conservation challenge, since they breed widely in the circumpolar Arctic, with many declining populations in the Atlantic. Threats facing murres include hunting, oil spills, bycatch and oceanic change influencing prey availability. Previous knowledge of migration pathways was insufficient to estimate the composition of various wintering populations. We collated tracking data (light-based geolocation) of 320 murres from 18 colonies in Canada, Greenland, Iceland, Svalbard and mainland Norway. Data were combined with breeding population counts to estimate the size and composition of wintering populations. The main wintering areas were off Newfoundland and Labrador, off West Greenland, and around Iceland. Winter areas were associated with the interface between High and Low Arctic ocean regimes. There was strong correspondence between wintering area and breeding population status: stable populations breeding in Canada and Northwest Greenland wintered mainly off Canada, whereas declining populations from Svalbard and Iceland wintered mainly off West Greenland and around Iceland. Many populations used distinct post-breeding areas, presumably for moulting; some of these areas were previously unknown. In some populations, there was a clear tendency for females to migrate south earlier than males, which accompany flightless fledglings when they leave the colony. Our study provides a key example of the urgency of coordinated, transoceanic management of vulnerable migratory species such as seabirds.
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breeding stage
2015Co-Authors: Anthony J. Gaston, Mark J. HipfnerAbstract:Body mass changes in Brünnich’s guillemots Uria lomvia with age an
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Organohalogen contaminants and total mercury in forage fish preyed upon by thick-billed murres in northern Hudson Bay
Marine Pollution Bulletin, 2013Co-Authors: Birgit M. Braune, Anthony J. Gaston, Jennifer F Provencher, Kyle H. Elliott, Kerry J. Woo, Magaly Chambellant, Steven H. Ferguson, Robert J. LetcherAbstract:Twelve marine fish species collected from a thick-billed murre (Uria lomvia) breeding colony in northern Hudson Bay in the Canadian Arctic during 2007–2009 were analyzed for legacy organochlorines (e.g. PCBs, DDT), polybrominated diphenyl ethers (PBDEs), perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs), and total mercury (Hg). No one species of prey fish had the highest levels across all contaminant groups analyzed. For the two pelagic fish species sampled, concentrations of the major organochlorine groups (e.g. Σ21PCB, ΣDDT, ΣCHL, ΣCBz), ΣPBDE, ΣPFCA and Hg were consistently higher in Arctic cod (Boreogadus saida) than in capelin (Mallotus villosus). Biomagnification factors from whole fish to thick-billed murre liver across all species were generally higher for Σ21PCB and ΣDDT. ΣPBDE did not biomagnify.
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Movements and wintering areas of breeding age Thick-billed Murre Uria lomvia from two colonies in Nunavut, Canada
Marine Biology, 2011Co-Authors: Anthony J. Gaston, Mark L. Mallory, Gregory J. Robertson, William A. Montevecchi, April Hedd, David A. Fifield, H. Grant Gilchrist, Paul A. Smith, Laura Mcfarlane Tranquilla, Richard A. PhillipsAbstract:The non-breeding movements of marine birds were poorly known until recently, but this information is essential to understanding the risk to different geographical populations from events on the wintering grounds. We tracked the migration routes and wintering areas of Thick-billed Murre Uria lomvia from two breeding colonies in eastern Canada: Coats Island in northern Hudson Bay and The Minarets, Baffin Island, during the period August 2007–May 2008 using geolocation loggers. Birds from The Minarets moved south rapidly post-breeding and wintered principally off Newfoundland and southern Labrador, or between Newfoundland and southern Greenland, remaining south of 55°N until at least the spring equinox. Those from Coats Island remained in Hudson Bay until at least mid-November, after which they moved rapidly through Hudson Strait to winter in southern Davis Strait and the northern Labrador Sea, mostly north of 55°N. Many individuals stayed throughout the winter in areas of heavy ice cover. Adults from the two colonies appear to be completely segregated in winter and those from Coats Island probably did not enter the area of the winter hunt in Newfoundland. Unexpectedly, some birds from The Minarets wintered in waters beyond the continental slope and outside the distribution of pack ice, demonstrating that particular individuals can be wholly pelagic throughout the winter. Coats Island birds returned through Hudson Strait as soon as open water areas became available in spring. Their sojourn in Hudson Bay coincided very closely with the occurrence of areas with
H. Grant Gilchrist - One of the best experts on this subject based on the ideXlab platform.
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The formation of foraging aggregations in a highly social seabird, the thick-billed murre ( Uria lomvia ), at small and large scales
Marine Biology, 2018Co-Authors: Émile Brisson-curadeau, Akinori Takahashi, H. Grant Gilchrist, Pierre Dutilleul, Kyle H. ElliottAbstract:Analyzing how animals are distributed in space and time is important to understand the behavioural interactions that underlie population dynamics, especially for highly social species. Thick-billed murres (Uria lomvia) breed in some of the largest and densest colonies of any seabird. Although this bird is known to aggregate at sea, little is known about when, where, and why the birds form aggregations. We examined the spatial and temporal patterns of foraging aggregations during the breeding season through various scales via (1) measurement of the synchrony of arrivals of adults feeding their chicks at the colony, and (2) use of both GPS and camera loggers attached on the birds to examine the proximity of birds at sea. Adult arrivals at the colony were synchronised when bringing capelin (Mallotus villosus), a gregarious pelagic fish, but not when bringing sculpin (primarily Triglops spp.), a solitary benthic fish. Camera loggers revealed very close encounters of foraging conspecific (< 4 m), much closer than what was predicted by chance, despite low prey densities. GPS loggers also showed diffuse at-sea aggregations with minimal distances closer than expected by chance. However, those study birds did not typically share foraging trajectories. We suggest that, at smaller scales, murres form tight groups to increase searching efficiency underwater. At larger scales, murre aggregations are most likely a result of foraging individuals converging in the more prolific areas, either by independently encountering prey hotspots, or by cueing on other foraging birds.
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Movements and wintering areas of breeding age Thick-billed Murre Uria lomvia from two colonies in Nunavut, Canada
Marine Biology, 2011Co-Authors: Anthony J. Gaston, Mark L. Mallory, Gregory J. Robertson, William A. Montevecchi, April Hedd, David A. Fifield, H. Grant Gilchrist, Paul A. Smith, Laura Mcfarlane Tranquilla, Richard A. PhillipsAbstract:The non-breeding movements of marine birds were poorly known until recently, but this information is essential to understanding the risk to different geographical populations from events on the wintering grounds. We tracked the migration routes and wintering areas of Thick-billed Murre Uria lomvia from two breeding colonies in eastern Canada: Coats Island in northern Hudson Bay and The Minarets, Baffin Island, during the period August 2007–May 2008 using geolocation loggers. Birds from The Minarets moved south rapidly post-breeding and wintered principally off Newfoundland and southern Labrador, or between Newfoundland and southern Greenland, remaining south of 55°N until at least the spring equinox. Those from Coats Island remained in Hudson Bay until at least mid-November, after which they moved rapidly through Hudson Strait to winter in southern Davis Strait and the northern Labrador Sea, mostly north of 55°N. Many individuals stayed throughout the winter in areas of heavy ice cover. Adults from the two colonies appear to be completely segregated in winter and those from Coats Island probably did not enter the area of the winter hunt in Newfoundland. Unexpectedly, some birds from The Minarets wintered in waters beyond the continental slope and outside the distribution of pack ice, demonstrating that particular individuals can be wholly pelagic throughout the winter. Coats Island birds returned through Hudson Strait as soon as open water areas became available in spring. Their sojourn in Hudson Bay coincided very closely with the occurrence of areas with
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Variation in Egg Size and Laying Date in Thick-Billed Murre Populations Breeding in the Low Arctic and High Arctic
The Condor, 2005Co-Authors: J. Mark Hipfner, Anthony J. Gaston, H. Grant GilchristAbstract:Abstract We used data collected across 28 years (1975–2002) to compare how timing of laying and egg size respond to environmental variability in two low-arctic and two high-arctic Thick-billed Murre (Uria lomvia) populations. Ice conditions strongly affect food availability to marine birds in the Arctic, and the percentage of the sea's surface covered by ice within 300 km of the breeding colony varied more among years near the start of laying at our high-arctic study colonies (Prince Leopold and Coburg Islands, Nunavut, Canada) than at our low-arctic study colonies (Coats and Digges Islands, Nunavut). However, mean values differed little. These results indicate that Thick-billed Murres breeding in the High Arctic experience more variable ice conditions, but not necessarily more severe ice conditions, during the period of egg formation. In response, both median laying date and mean egg size varied more among years at high-arctic than at low-arctic colonies. Several lines of evidence suggested that the variation was a result of within-female effects, i.e., phenotypic plasticity rather than different individuals breeding in years in which environmental conditions differed. Previous studies have shown that Thick-billed Murres lay eggs later in years of heavier ice coverage, especially in the High Arctic where ice conditions can be severe, and only in the High Arctic was later laying associated with reduced egg size. The relationship tended towards a negative asymptote suggesting that each female may have her own minimum egg size. Our results show that Thick-billed Murres that inhabit a more variable environment display greater variability in life-history traits. More generally, they offer insight into mechanisms linking environmental heterogeneity to phenotypic variation in life-history traits. Variación en el Tamaño del Huevo y la Fecha de Puesta en Poblaciones Reproductivas de Uria lomvia en el Ártico Bajo y el Ártico Alto Resumen. Empleamos datos colectados a lo largo de 28 años (1975–2002) para determinar cómo el ajuste temporal de la puesta y del tamaño del huevo responde a la variabilidad ambiental en dos poblaciones del Ártico bajo y dos poblaciones del Ártico alto de Uria lomvia. Las condiciones del hielo afectaron fuertemente la disponibilidad de alimentos para las aves marinas en el Ártico. El porcentaje de la superficie del mar cubierta por hielo a menos de 300 km de la colonia reproductiva varió más entre años cerca del inicio de la puesta en nuestras colonias de estudio del Ártico alto (Islas Prince Leopold y Coburg, Nunavut, Canadá) que en nuestras colonias de estudio del Ártico bajo (Islas Coats and Digges, Nunavut). Sin embargo, los valores medios difirieron poco. Estos resultados indican que los individuos de Uria lomvia que crían en el Ártico alto experimentan condiciones de hielo más variables, pero no necesariamente más severas, durante el período de la formación del huevo. Como respuesta, tanto la fecha mediana de puesta y la media del tamaño del huevo variaron más entre años en las colonias del Ártico alto que en las del Ártico bajo. Varias líneas de evidencia sugirieron que esta variación fue el resultado de variaciones propias de las hembras (i.e., plasticidad fenotípica) y no de variación entre individuos diferentes que criaron en años en los cuales las condiciones ambientales difirieron. Estudios previos han mostrado que Uria lomvia realiza su puesta más tarde en los años de mucha cobertura de hielo, especialmente en el Ártico alto, donde las condiciones de hielo pueden ser severas, y sólo en el Ártico alto la demora de la puesta se asoció con una reducción del tamaño del huevo. La relación tendió hacia una asíntota negativa, sugiriendo que cada hembra podría tener su propio tamaño mínimo del huevo. Nuestros resultados muestran que los individuos de Uria lomvia que habitan un ambiente más variable muestran mayor variabilidad en los rasgos de historia de vida. De modo más general, nuestros resultados ofrecen información sobre los mecanismos que vinculan la heterogeneidad ambiental con la variación fenotípica en los rasgos de historia de vida.
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Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich's guillemot (Uria lomvia L.)
Journal of Animal Ecology, 2005Co-Authors: Anthony J. Gaston, H. Grant Gilchrist, J. Mark HipfnerAbstract:Summary 1 We compared the reproduction of a marine diving bird, Brunnich's guillemot (Uria lomvia), breeding at two Arctic colonies close to the northern and southern limits of the species’ range in the Canadian Arctic. 2 At both colonies, timing of breeding for Brunnich's guillemots was positively correlated with summer ice cover, which was determined by winter and spring temperatures. Spring temperatures also modified the effects of ice conditions on timing of breeding. 3 At Coats Island, northern Hudson Bay, in low Arctic waters, the date of egg-laying has advanced since 1981, simultaneous with a decrease in summer ice cover in surrounding waters. Lower ice cover in this region is correlated with lower chick growth rates and lower adult body mass, suggesting that reduction in summer ice extent is having a negative effect on reproduction. 4 Conversely, at Prince Leopold Island, in the High Arctic, there has been no trend in summer ice cover and no detectable change in timing of breeding. Reproduction there is less successful in years of late ice than in years of early ice break-up. 5 Current trends suggest that continued warming should benefit birds breeding on the northern limit of the species range, while adversely affecting reproduction for those on the southern margin. The probable result will be an eventual northward displacement of the population. Although this type of effect has been widely predicted, this study is among the first to demonstrate a potential causal mechanism.
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Declining thick-billed murre Uria lomvia colonies experience higher gull predation rates: an inter-colony comparison
Biological Conservation, 1999Co-Authors: H. Grant GilchristAbstract:Abstract Avian predators of colonial-nesting seabirds preferentially attack individuals nesting alone or on the edge of groups, apparently because they can forage without being struck by defending neighbours. If nesting densities of colonial seabirds declined, predators are predicted to have fewer foraging constraints and consequently a greater impact on seabird reproduction. Thus, avian predation could prevent the recovery of seabird populations once sources of adult mortality have been removed. To test these predictions, glaucous gull Larus hyperboreus predation rates, foraging mode selection and murre nest-site selection at an expanding thick-billed murre Uria lomvia colony (Coats Island, Canada) were compared with those at declining murre colonies in Northwest Greenland (Timmiak, Kingittoq). At Coats Island, most cliff ledges were densely occupied by breeding murres so that gulls could not forage extensively on foot. Gulls relied on wind when foraging (>10 km/h), which enhanced their aerial maneuverability and enabled them to reach nest sites on narrow ledges that were poorly defended. In contrast, glaucous gulls at Kingittoq foraged on foot regardless of wind conditions because broad ledges supported small breeding groups of murres. This resulted in higher attack and predation rates of murres at low wind speeds at Kingittoq. At Timmiak, which had experienced the greatest population declines, murres nested at high densities on narrow ledges or in crevices inaccessible to gulls. It was concluded that lower nesting densities at declining colonies reduce the risk of injury for gulls during attack and that this increases predation rates at low wind speeds. These findings suggest that seabird population declines that result from human-induced mortality (e.g. over-harvest) can increase the impact of avian predators on seabird reproduction and potentially, slow the recovery of colonies.
J. Mark Hipfner - One of the best experts on this subject based on the ideXlab platform.
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Adult Brünnich's Guillemots Uria lomvia balance body condition and investment in chick growth
Ibis, 2006Co-Authors: Anthony J. Gaston, J. Mark HipfnerAbstract:To investigate the covariation of adult body condition and nestling growth, we weighed adult Brunnich’s Guillemots Uria lomvia rearing chicks at Coats Island, Nunavut, Canada, each year between 1988 and 2002. We estimated chick mass at 14 days for a sample of chicks reared in the same years. Adult mass and chick mass at 14 days were highly correlated, suggesting that, as feeding conditions deteriorate, adults compromise by reducing their own body reserves, while at the same time delivering less food to their offspring. We compared the prediction of the least-squares regression for the Coats Island data with observations made at Digges Island, a much larger colony about 300 km away, where birds are similar in linear body measurements to those at Coats Island and have a similar body mass while incubating. Adult mass at Digges Island averaged 11% less during chick-rearing than during incubation, compared with only a 5% difference at Coats Island. Mean chick mass at 14 days at Digges Island was lower in all years than was observed for chicks at Coats Island in any year. The observed 14-day chick masses at Digges Island in two years were close to values predicted by adult mass and somewhat lower in two other years (those when chick growth was slowest). At Digges Island, the distribution of mass for brooding adults was right skewed and suggested a lower threshold at 800‐850 g, below which Brunnich’s Guillemots terminate breeding. We conclude that the correlation between adult and chick mass represents a dynamic equilibrium in which adults simultaneously adjust their own energy reserves and their delivery rate to the chick. This compromise must be based on behavioural choices made by individual birds and is unlikely to be a passive consequence of fluctuating conditions.
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Body mass changes in Brunnich's guillemots Uria lomvia with age and breeding stage
Journal of Avian Biology, 2006Co-Authors: Anthony J. Gaston, J. Mark HipfnerAbstract:Body mass of Brunnich's guillemots Uria lomvia breeding at Coats Island, Canada, was measured during incubation and chick-rearing in 1988–2001. In most years, mass increased during incubation and fell after hatching, leveling off by the time chicks were 18 d old, close to the age at which chicks departed. Mass during incubation increased with age up to about 12 yr, but the mass of birds brooding chicks was not related to age. The trend towards increasing mass during incubation was mainly a consequence of mass increases of young breeders as older birds maintained a constant mass. The variation in adult mass with age during incubation seems likely to reflect age-related variation in foraging ability, but the loss of mass after hatching, being greater for older birds, appears best explained as a response to the demands of provisioning chicks, with older birds transferring their accumulated reserves to their chicks via higher provisioning rates.
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Variation in Egg Size and Laying Date in Thick-Billed Murre Populations Breeding in the Low Arctic and High Arctic
The Condor, 2005Co-Authors: J. Mark Hipfner, Anthony J. Gaston, H. Grant GilchristAbstract:Abstract We used data collected across 28 years (1975–2002) to compare how timing of laying and egg size respond to environmental variability in two low-arctic and two high-arctic Thick-billed Murre (Uria lomvia) populations. Ice conditions strongly affect food availability to marine birds in the Arctic, and the percentage of the sea's surface covered by ice within 300 km of the breeding colony varied more among years near the start of laying at our high-arctic study colonies (Prince Leopold and Coburg Islands, Nunavut, Canada) than at our low-arctic study colonies (Coats and Digges Islands, Nunavut). However, mean values differed little. These results indicate that Thick-billed Murres breeding in the High Arctic experience more variable ice conditions, but not necessarily more severe ice conditions, during the period of egg formation. In response, both median laying date and mean egg size varied more among years at high-arctic than at low-arctic colonies. Several lines of evidence suggested that the variation was a result of within-female effects, i.e., phenotypic plasticity rather than different individuals breeding in years in which environmental conditions differed. Previous studies have shown that Thick-billed Murres lay eggs later in years of heavier ice coverage, especially in the High Arctic where ice conditions can be severe, and only in the High Arctic was later laying associated with reduced egg size. The relationship tended towards a negative asymptote suggesting that each female may have her own minimum egg size. Our results show that Thick-billed Murres that inhabit a more variable environment display greater variability in life-history traits. More generally, they offer insight into mechanisms linking environmental heterogeneity to phenotypic variation in life-history traits. Variación en el Tamaño del Huevo y la Fecha de Puesta en Poblaciones Reproductivas de Uria lomvia en el Ártico Bajo y el Ártico Alto Resumen. Empleamos datos colectados a lo largo de 28 años (1975–2002) para determinar cómo el ajuste temporal de la puesta y del tamaño del huevo responde a la variabilidad ambiental en dos poblaciones del Ártico bajo y dos poblaciones del Ártico alto de Uria lomvia. Las condiciones del hielo afectaron fuertemente la disponibilidad de alimentos para las aves marinas en el Ártico. El porcentaje de la superficie del mar cubierta por hielo a menos de 300 km de la colonia reproductiva varió más entre años cerca del inicio de la puesta en nuestras colonias de estudio del Ártico alto (Islas Prince Leopold y Coburg, Nunavut, Canadá) que en nuestras colonias de estudio del Ártico bajo (Islas Coats and Digges, Nunavut). Sin embargo, los valores medios difirieron poco. Estos resultados indican que los individuos de Uria lomvia que crían en el Ártico alto experimentan condiciones de hielo más variables, pero no necesariamente más severas, durante el período de la formación del huevo. Como respuesta, tanto la fecha mediana de puesta y la media del tamaño del huevo variaron más entre años en las colonias del Ártico alto que en las del Ártico bajo. Varias líneas de evidencia sugirieron que esta variación fue el resultado de variaciones propias de las hembras (i.e., plasticidad fenotípica) y no de variación entre individuos diferentes que criaron en años en los cuales las condiciones ambientales difirieron. Estudios previos han mostrado que Uria lomvia realiza su puesta más tarde en los años de mucha cobertura de hielo, especialmente en el Ártico alto, donde las condiciones de hielo pueden ser severas, y sólo en el Ártico alto la demora de la puesta se asoció con una reducción del tamaño del huevo. La relación tendió hacia una asíntota negativa, sugiriendo que cada hembra podría tener su propio tamaño mínimo del huevo. Nuestros resultados muestran que los individuos de Uria lomvia que habitan un ambiente más variable muestran mayor variabilidad en los rasgos de historia de vida. De modo más general, nuestros resultados ofrecen información sobre los mecanismos que vinculan la heterogeneidad ambiental con la variación fenotípica en los rasgos de historia de vida.
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Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich's guillemot (Uria lomvia L.)
Journal of Animal Ecology, 2005Co-Authors: Anthony J. Gaston, H. Grant Gilchrist, J. Mark HipfnerAbstract:Summary 1 We compared the reproduction of a marine diving bird, Brunnich's guillemot (Uria lomvia), breeding at two Arctic colonies close to the northern and southern limits of the species’ range in the Canadian Arctic. 2 At both colonies, timing of breeding for Brunnich's guillemots was positively correlated with summer ice cover, which was determined by winter and spring temperatures. Spring temperatures also modified the effects of ice conditions on timing of breeding. 3 At Coats Island, northern Hudson Bay, in low Arctic waters, the date of egg-laying has advanced since 1981, simultaneous with a decrease in summer ice cover in surrounding waters. Lower ice cover in this region is correlated with lower chick growth rates and lower adult body mass, suggesting that reduction in summer ice extent is having a negative effect on reproduction. 4 Conversely, at Prince Leopold Island, in the High Arctic, there has been no trend in summer ice cover and no detectable change in timing of breeding. Reproduction there is less successful in years of late ice than in years of early ice break-up. 5 Current trends suggest that continued warming should benefit birds breeding on the northern limit of the species range, while adversely affecting reproduction for those on the southern margin. The probable result will be an eventual northward displacement of the population. Although this type of effect has been widely predicted, this study is among the first to demonstrate a potential causal mechanism.
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Egg Composition in Relation to Female Age and Relaying: Constraints on Egg Production in Thick-Billed Murres (Uria lomvia)
The Auk, 2003Co-Authors: J. Mark Hipfner, Anthony J. Gaston, Gene R. Herzberg, John T. Brosnan, Anne E. StoreyAbstract:Abstract There is growing awareness that costs associated with egg production play a significant role in shaping avian life histories. The life-history strategy of the Thick-billed Murre (Uria lomvia), a colonial, cliff-breeding seabird of Arctic waters, is characterized by a high annual adult survival rate, deferred breeding, and laying of a single-egg clutch. The single-egg clutch is a widespread phenomenon among seabirds and is generally thought to reflect demands of chick provisioning, rather than egg production. We compared composition of eggs laid by Thick-billed Murres most likely to be physiologically constrained in their capacity to produce eggs (young females with no prior experience, and females forming replacement eggs) to that of first eggs laid by early laying females (typically older, more experienced members of the population). Young, inexperienced females laid 4–18 days past the populationwide median laying date, and their eggs averaged 13% lighter in mass than those laid by early layers. Compared to early laid eggs, shell mass on young females’ eggs was similar to that predicted from egg mass, but their eggs had a lower yolk-to-albumen ratio. There was little difference between the two groups in relative protein content of albumen, relative protein or lipid content of yolk, or amino acid makeup of protein in yolk or albumen. Replacement eggs averaged 6% lighter in mass than first eggs laid by the same females earlier that season. As with young females’ eggs, replacement eggs had shells similar in mass to that predicted from egg mass, but lower yolk-to-albumen ratios, when compared to early laid eggs. Both protein and lipid concentrations in yolk were similar in first and replacement eggs, but replacements were deficient in albumen protein. Amino acid makeup of protein in yolk and albumen was similar in the two groups. Those results suggest that any limitations on egg production acting on young, inexperienced females are manifested in delayed laying and reductions in overall egg mass and proportional yolk content, but not in variation in biochemical composition of their eggs. Limitations on females forming replacement eggs are manifested not only in reduced egg mass and yolk content (as with young females), but also in changes in the biochemical composition of eggs; in particular, evidence suggests that relaying females may face a deficit of endogenous protein. The existence of such limitations suggests that demands of egg production can be significant even in a species that lays a single-egg clutch.
Kyle H. Elliott - One of the best experts on this subject based on the ideXlab platform.
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Gut microbiome is affected by inter-sexual and inter-seasonal variation in diet for thick-billed murres ( Uria lomvia )
Scientific reports, 2021Co-Authors: Esteban Góngora, Kyle H. Elliott, Lyle G. WhyteAbstract:The role of the gut microbiome is increasingly being recognized by health scientists and veterinarians, yet its role in wild animals remains understudied. Variations in the gut microbiome could be the result of differential diets among individuals, such as variation between sexes, across seasons, or across reproductive stages. We evaluated the hypothesis that diet alters the avian gut microbiome using stable isotope analysis (SIA) and 16S rRNA gene sequencing. We present the first description of the thick-billed murre (Uria lomvia) fecal microbiome. The murre microbiome was dominated by bacteria from the genus Catellicoccus, ubiquitous in the guts of many seabirds. Microbiome variation was explained by murre diet in terms of proportion of littoral carbon, trophic position, and sulfur isotopes, especially for the classes Actinobacteria, Bacilli, Bacteroidia, Clostridia, Alphaproteobacteria, and Gammaproteobacteria. We also observed differences in the abundance of bacterial genera such as Catellicoccus and Cetobacterium between sexes and reproductive stages. These results are in accordance with behavioural observations of changes in diet between sexes and across the reproductive season. We concluded that the observed variation in the gut microbiome may be caused by individual prey specialization and may also be reinforced by sexual and reproductive stage differences in diet.
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The formation of foraging aggregations in a highly social seabird, the thick-billed murre ( Uria lomvia ), at small and large scales
Marine Biology, 2018Co-Authors: Émile Brisson-curadeau, Akinori Takahashi, H. Grant Gilchrist, Pierre Dutilleul, Kyle H. ElliottAbstract:Analyzing how animals are distributed in space and time is important to understand the behavioural interactions that underlie population dynamics, especially for highly social species. Thick-billed murres (Uria lomvia) breed in some of the largest and densest colonies of any seabird. Although this bird is known to aggregate at sea, little is known about when, where, and why the birds form aggregations. We examined the spatial and temporal patterns of foraging aggregations during the breeding season through various scales via (1) measurement of the synchrony of arrivals of adults feeding their chicks at the colony, and (2) use of both GPS and camera loggers attached on the birds to examine the proximity of birds at sea. Adult arrivals at the colony were synchronised when bringing capelin (Mallotus villosus), a gregarious pelagic fish, but not when bringing sculpin (primarily Triglops spp.), a solitary benthic fish. Camera loggers revealed very close encounters of foraging conspecific (< 4 m), much closer than what was predicted by chance, despite low prey densities. GPS loggers also showed diffuse at-sea aggregations with minimal distances closer than expected by chance. However, those study birds did not typically share foraging trajectories. We suggest that, at smaller scales, murres form tight groups to increase searching efficiency underwater. At larger scales, murre aggregations are most likely a result of foraging individuals converging in the more prolific areas, either by independently encountering prey hotspots, or by cueing on other foraging birds.
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Organohalogen contaminants and total mercury in forage fish preyed upon by thick-billed murres in northern Hudson Bay
Marine Pollution Bulletin, 2013Co-Authors: Birgit M. Braune, Anthony J. Gaston, Jennifer F Provencher, Kyle H. Elliott, Kerry J. Woo, Magaly Chambellant, Steven H. Ferguson, Robert J. LetcherAbstract:Twelve marine fish species collected from a thick-billed murre (Uria lomvia) breeding colony in northern Hudson Bay in the Canadian Arctic during 2007–2009 were analyzed for legacy organochlorines (e.g. PCBs, DDT), polybrominated diphenyl ethers (PBDEs), perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs), and total mercury (Hg). No one species of prey fish had the highest levels across all contaminant groups analyzed. For the two pelagic fish species sampled, concentrations of the major organochlorine groups (e.g. Σ21PCB, ΣDDT, ΣCHL, ΣCBz), ΣPBDE, ΣPFCA and Hg were consistently higher in Arctic cod (Boreogadus saida) than in capelin (Mallotus villosus). Biomagnification factors from whole fish to thick-billed murre liver across all species were generally higher for Σ21PCB and ΣDDT. ΣPBDE did not biomagnify.
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Sex-specific behavior by a monomorphic seabird represents risk partitioning
Behavioral Ecology, 2010Co-Authors: Kyle H. Elliott, Anthony J. Gaston, Douglas CrumpAbstract:The presence of sex-stereotyped behavior in monomorphic animals, where there are no sexual differences in form to account for sexual differences in function, is often attributed to intraspecific competition or to differential parental investment. The possibility that the use of different behavioral strategies by each parent may increase reproductive success for both partners through risk partitioning is seldom considered. We studied thick-billed murres (Uria lomvia), where the male exclusively feeds the offspring during the late chick rearing. During the period of biparental care, males fed on ‘‘risk-averse’’ prey (consistent across time and space; unitized risk ¼ 0.29), whereas females fed on ‘‘risk-prone’’ prey (risk ¼ 0.59). Males fed at night at 1 colony, during the day at 2 colonies, and there was no pattern at another colony. We suggest that these differences reflect the availability of risk-prone prey. Modeling suggested that mixed-risk pairs had higher success than ‘‘risky’’ or ‘‘riskless’’ pairs. Males accumulated reserves and reduced chick provisioning just prior to fledging. Thus, sex-specific patterns at 1 period (male-only care during postfledging) may have led to sex-specific patterns at earlier periods through the need for specialization in foraging habits and risk. We propose that risk partitioning may contribute to the prevalence of sex-specific behaviors in monomorphic animals and that patterns are likely context specific rather than species specific. Key words: risk aversion, sex-specific behavior, thick-billed murre, Uria lomvia. [Behav Ecol]
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Is mass loss in Brünnich's guillemots Uria lomvia an adaptation for improved flight performance or improved dive performance?
Journal of Avian Biology, 2008Co-Authors: Kyle H. Elliott, Anthony J. Gaston, Shoshanah R. Jacobs, Julian Ringrose, Gail K. DavorenAbstract:Breeding Brunnich's guillemots Uria lomvia show stepwise mass loss at the time of hatch. This mass loss has usually been explained as an adaptation to reduce the cost of flight during the chick-rearing period because flight time increases during that period. It is possible, however, that mass loss also increases dive performance during the chick-rearing period because time spent diving also increases during that period. Reduced mass could reduce basal metabolic rate or costs associated with buoyancy and therefore increase aerobic dive limit. To examine the role of mass loss in dive behavior, we attached time-depth-temperature recorders for 24� 48 h to chick-rearing and incubating Brunnich's guillemots at Coats Island, Nunavut (2005: n� 45, 2006: n � 40), and recorded body mass before and after each deployment. There was no relationship between mass and dive duration during either incubation or chick-rearing. Seventeen of the birds we sampled during incubation were resampled during chick-rearing. For this group, dive duration increased with mass loss between incubation and chick-rearing (r 2 � 0.67� 0.75). Mass loss occurred through reductions in metabolically-active tissues (liver, bladder) and buoyant tissues (lipids) although muscle and gut mass did not change. Despite the large change in lipids, buoyancy only changed by 0.1%, and mass loss therefore did not have much effect on costs associated with buoyancy. Nonetheless, surface pause duration for a given dive depth decreased during chick-rearing, supporting the idea that reduced mass led to increased aerobic dive limit through reduced metabolic rate and inertial costs; oxygen stores did not increase. We also attached neutrally (n � 9) and negatively (n � 11) buoyant handicaps to the legs of adults to assess the effect of artificial mass increases on time budgets. Artificially increasing mass decreased total time spent diving but did not change time spent flying. There was no change in shift length between incubation and chick-rearing, and therefore no support for the idea that mass loss reflected a change in fasting endurance requirements. An energetic model suggested that the observed mass reduction reduced dive costs by 5� 8% and flight costs by 3%. We concluded that mass loss may be as important for increasing dive performance as increasing flight performance.
Vicki L. Friesen - One of the best experts on this subject based on the ideXlab platform.
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Assembly and RNA-free annotation of highly heterozygous genomes: The case of the thick-billed murre (Uria lomvia).
Molecular ecology resources, 2017Co-Authors: Anna Tigano, Timothy B. Sackton, Vicki L. FriesenAbstract:Thanks to a dramatic reduction in sequencing costs followed by a rapid development of bioinformatics tools, genome assembly and annotation have become accessible to many researchers in recent years. Among tetrapods, birds have genomes that display many features that facilitate their assembly and annotation, such as small genome size, low number of repeats and highly conserved genomic structure. However, we found that high genomic heterozygosity could have a great impact on the quality of the genome assembly of the thick-billed murre (Uria lomvia), an arctic colonial seabird. In this study, we tested the performance of three genome assemblers, ray/sscape, soapdenovo2 and platanus, in assembling the highly heterozygous genome of the thick-billed murre. Our results show that platanus, an assembler specifically designed for heterozygous genomes, outperforms the other two approaches and produces a highly contiguous (N50 = 15.8 Mb) and complete genome assembly (93% presence of genes from the Benchmarking Universal Single Copy Ortholog [BUSCO] gene set). Additionally, we annotated the thick-billed murre genome using a homology-based approach that takes advantage of the genomic resources available for birds and other taxa. Our study will be useful for those researchers who are approaching assembly and annotation of highly heterozygous genomes, or genomes of species of conservation concern, and/or who have limited financial resources.
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The Arctic: Glacial Refugium or Area of Secondary Contact? Inference from the Population Genetic Structure of the Thick-Billed Murre (Uria lomvia), with Implications for Management
The Journal of heredity, 2015Co-Authors: Anna Tigano, Martin Damus, Tim P. Birt, Jamie A. Morris-pocock, Yuri B. Artukhin, Vicki L. FriesenAbstract:Quaternary glaciations affected the distribution of many species. Here, we investigate whether the Arctic represented a glacial refugium during the Last Glacial Maximum or an area of secondary contact following the ice retreat, by analyzing the genetic population structure of the thick-billed murre (Uria lomvia), a seabird that breeds throughout the North Atlantic, North Pacific and Arctic Oceans. The thick-billed murre is a species of socio-economic importance and faces numerous threats including hunting, oil pollution, gill netting, and climate change. We compared variation in the mitochondrial DNA (mtDNA) control region (n = 424), supplemented by 4 microsatellite loci (n = 445), among thick-billed murres sampled throughout their range. MtDNA data indicated that colonies comprise 4 genetically differentiated groups (Φst = 0.11-0.81): 1) Atlantic Ocean plus New Siberian Islands region, 2) Cape Parry, 3) Chukchi Sea, and 4) Pacific Ocean. Microsatellite variation differed between Atlantic and Pacific populations. Otherwise, little substructure was found within either ocean. Atlantic and Pacific populations appear to have been genetically isolated since the last interglacial period and should be considered separate evolutionary significant units for management. The Chukchi Sea and Cape Parry appear to represent areas of secondary contact, rather than arctic refugial populations.
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Philopatry, morphological divergence, and kin groups: structuring in thick‐billed murres Uria lomvia within a colony in Arctic Canada
Journal of Avian Biology, 2011Co-Authors: G. Ibarguchi, Anthony J. Gaston, Vicki L. FriesenAbstract:Many seabirds exhibit high natal philopatry despite their extreme dispersal ability and delayed reproduction, and some exhibit phenotypic clustering in colonies and fostering or adoption of neighbouring chicks. Previous investigations of kinship in a small thick-billed murre colony Uria lomvia (Alcidae) in Norway revealed high relatedness among breeders on cliff ledges. To investigate the presence of kin groups and within-colony genetic sub-structuring elsewhere, we investigated kinship within a larger murre colony on Coats Island, Nunavut, Canada. Morphological (five characters) and genetic data (five microsatellite loci and a fragment of the mitochondrial cytochrome b gene) were analysed. Strong morphological differentiation was found among ledges. Genetic structuring was overall weak but significant at the coarse scale for males among ledges and on the east vs. the west side of the colony. Global spatial autocorrelation analyses did not detect consistent, widespread spatial patterns, although local 2D analyses provided some evidence of a tendency for larger neighbourhood sizes for females and a broad range of small to large neighbourhoods for males. Average within-ledge relatedness was low overall, but ranged widely from slightly unrelated to greater than the level of cousins in both sexes. Kin-level relationships occurred on ledges more frequently for same-sex groups than expected by chance, suggesting that recruiting breeders (especially females) avoid or are unable to settle directly adjacent to relatives particularly of the opposite sex. Behavioural studies of natal dispersal of murres at Coats I. indicating that both sexes are highly philopatric, but that up to one-fifth of females may disperse, are concordant with this study. Overall, structuring was weaker than in Norway, and may be explained in part by genetic marker and sampling artifacts, and by the lack of genetic equilibrium suspected in the much larger Canadian Arctic colony. Natal philopatry may be an important factor driving the diversification of seabirds and kin groups in other colonies and species and may be more widespread than is currently acknowledged.
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philopatry morphological divergence and kin groups structuring in thick billed murres Uria lomvia within a colony in arctic canada
Journal of Avian Biology, 2011Co-Authors: G. Ibarguchi, Anthony J. Gaston, Vicki L. FriesenAbstract:Many seabirds exhibit high natal philopatry despite their extreme dispersal ability and delayed reproduction, and some exhibit phenotypic clustering in colonies and fostering or adoption of neighbouring chicks. Previous investigations of kinship in a small thick-billed murre colony Uria lomvia (Alcidae) in Norway revealed high relatedness among breeders on cliff ledges. To investigate the presence of kin groups and within-colony genetic sub-structuring elsewhere, we investigated kinship within a larger murre colony on Coats Island, Nunavut, Canada. Morphological (five characters) and genetic data (five microsatellite loci and a fragment of the mitochondrial cytochrome b gene) were analysed. Strong morphological differentiation was found among ledges. Genetic structuring was overall weak but significant at the coarse scale for males among ledges and on the east vs. the west side of the colony. Global spatial autocorrelation analyses did not detect consistent, widespread spatial patterns, although local 2D analyses provided some evidence of a tendency for larger neighbourhood sizes for females and a broad range of small to large neighbourhoods for males. Average within-ledge relatedness was low overall, but ranged widely from slightly unrelated to greater than the level of cousins in both sexes. Kin-level relationships occurred on ledges more frequently for same-sex groups than expected by chance, suggesting that recruiting breeders (especially females) avoid or are unable to settle directly adjacent to relatives particularly of the opposite sex. Behavioural studies of natal dispersal of murres at Coats I. indicating that both sexes are highly philopatric, but that up to one-fifth of females may disperse, are concordant with this study. Overall, structuring was weaker than in Norway, and may be explained in part by genetic marker and sampling artifacts, and by the lack of genetic equilibrium suspected in the much larger Canadian Arctic colony. Natal philopatry may be an important factor driving the diversification of seabirds and kin groups in other colonies and species and may be more widespread than is currently acknowledged.
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Male-biased Mutation Rates and the Overestimation of Extrapair Paternity: Problem, Solution, and Illustration Using Thick-Billed Murres (Uria lomvia, Alcidae)
The Journal of heredity, 2004Co-Authors: G. Ibarguchi, Anthony J. Gaston, G. J. Gissing, Peter T. Boag, Vicki L. FriesenAbstract:The widespread utility of hypervariable loci in genetic studies derives from the high mutation rate, and thus the high polymorphism, of these loci. Recent evidence suggests that mutation rates can be extremely high and may be male biased (occurring in the male germ-line). These two factors combined may result in erroneous overestimates of extrapair paternity, since legitimate offspring with novel alleles will have more mismatches with respect to the biological father than the biological mother. As mutations are male driven, increasing the number of hypervariable loci screened may simply increase the number of mismatches between fathers and their legitimate offspring. Here we describe a simple statistic, the probability of resemblance (PR), to distinguish between mismatches due to parental misassignment versus mutation in either sex or null alleles. We apply this method to parentage data on thick-billed murres (Uria lomvia), and demonstrate that, without considering either mutations or male-biased mutation rates, cases of extrapair paternity (7% in this study) would be grossly overestimated (14.5%–22%). The probability of resemblance can be utilized in parentage studies of any sexually reproducing species when allele or haplotype frequency data are available for putative parents and offspring. We suggest calculating this probability to correctly categorize legitimate offspring when mutations and null alleles may cause mismatches.
