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William J. Sydeman - One of the best experts on this subject based on the ideXlab platform.
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annual prey consumption of a dominant seabird the Common Murre in the california current system
2008Co-Authors: Jennifer E Roth, Nadav Nur, Pete Warzybok, William J. SydemanAbstract:Roth, J. E., Nur, N., Warzybok, P., and Sydeman, W. J. 2008. Annual prey consumption of a dominant seabird, the Common Murre, in the California Current system. - ICES Journal of Marine Science, 65: 1046-1056.Information compiled from the literature on population size, diet composition, field metabolic rate, prey energy densities, and assimilation efficiency is used to estimate annual prey consumption by Common Murres (Uria aalge), between Cape Blanco, OR, and Point Conception, CA, USA. The population consumed an estimated 172 313 t of prey based on population estimates and diet data from the mid- to the late 1980s, including 50 125 t consumed by breeding adults, 36 940 t by non-breeding birds during the breeding season, 85 098 t by all birds during the wintering period, and 150 t by dependent chicks before their leaving the breeding colonies. The population in the mid-2000s consumed 225 235 t of prey based on population estimates from 2004, including 65 516 t consumed by breeding adults, 48 283 t by non-breeding birds during the breeding season, 111 226 t by all birds during the wintering period, and 210 t by chicks at breeding colonies. Monte Carlo simulations indicated that the coefficients of variation around our overall prey consumption estimates were ±14.4% for the 1980s and ±13.2% for the 2000s.
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Annual prey consumption of the Common Murre, a Dominant Seabird in the California Current
2008Co-Authors: William J. Sydeman, Nadav NurAbstract:In this project, researchers compiled information on Common Murre (Uria aalge) population size, diet, field metabolic rate, prey energy densities and assimilation efficiency to estimate the bird’s annual prey consumption between Cape Blanco, Ore. and Point Conception, California.
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diets of top predators indicate pelagic juvenile rockfish sebastes spp abundance in the california current system
2007Co-Authors: K.l. Mills, Stephen Ralston, Thomas E Laidig, William J. SydemanAbstract:Diets of top predators may be useful indicators to the availability of forage fish in marine ecosystems. Juvenile rockfish (young-of-the-year Sebastes spp.) compose a significant part of the diet for many predators in the central California Current, including chinook salmon (Oncorhynchus tshawytscha), and several species of marine birds and mammals. Herein, we develop annual indices of juvenile rockfish relative abundance by collating time series data sets on: (i) the proportion of rockfish in the diet of three species of seabirds breeding on Southeast Farallon Island (1975‐ 2002); (ii) the number of rockfish in chinook salmon stomachs (1980‐99); and (iii) the abundance of rockfish captured in scientific mid-water trawl net surveys (1983‐2002). We used Principal Component Analysis (PCA) to combine indices, and refer to these as ‘Multivariate Rockfish Indices’ (MRI). Combining time series verifies the patterns shown by each alone and provides a synoptic perspective on juvenile rockfish relative abundance. The diets of predators with the largest foraging ranges (Common Murre, Uria aalge) and chinook salmon co-varied strongly with the net samples, and appear to be the best indicators. The salmon also sampled species of Sebastes not caught in the nets. The MRI reveals interannual variability in juvenile rockfish abundance, a substantial decline in abundance in the 1990s, and a partial recovery in the early 2000s. Predator-based sampling is a cost-effective enhancement of scientific net sampling.
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rockfish response to low frequency ocean climate change as revealed by the diet of a marine bird over multiple time scales
2004Co-Authors: Aileen K. Miller, William J. SydemanAbstract:We examined the effects of ocean climate variability on juvenile rockfish Sebastes spp. from 1975-2002 in the central California Current by examining the diet of a local marine bird, the Common Murre Uria aalge, on multiple temporal scales. Responses to higher-frequency climate change (interannual El Nino and La Nina events) were strong, with declines in rockfish take in warm- water years. Responses to low-frequency climate events (e.g. shifts of the Pacific Decadal Oscillation, PDO) were less obvious. Inter-annual patterns showed no response to the 1976-1977 regime shift to warmer PDO conditions. Instead, rockfish use declined beginning in 1989, corresponding to another suggested regime change, then rebounded shortly after the hypothesized return to a cool phase of the PDO in the late 1990s. Intra-annual diet patterns, however, revealed changes in rockfish use well before 1989. These signals indicate that declines may have corresponded to the 1976-1977 regime shift but were lagged, possibly due to the long lifespan and intermittent recruitment of rockfish. This interpretation is supported by local upwelling patterns that show a lagged correlation between upwelling and juvenile rockfish abundance in the marine bird diet.
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marine bird and cetacean associations with bathymetric habitats and shallow water topographies implications for trophic transfer and conservation
2004Co-Authors: William J. Sydeman, David K HyrenbachAbstract:We investigated the aggregative response of marine birds and cetaceans to bathymetric features in central California over 4 years, 1996–1997 and 2001–2002. A total of 1700 km 2 of ocean habitat was surveyed over six cruises. We considered the distribution of the most abundant marine birds and mammals in relation to bathymetry. We focused our analyses on eight focal taxa: Cassin’s auklet (Ptychoramphus aleuticus), Common Murre (Uria aalge), sooty shearwater (Puffinus grieus), phalarope species (red, and red-necked: Phalaropus fulicaria, Phalaropus lobatus), Dall’s porpoise (Phocoenoides dalli), Pacific whitesided dolphin (Lagenorhynchus obliquidens), humpback whale (Megaptera novaeangliae), and Risso’s dolphin (Grampus griseus). We evaluated associations of top predators with seven bathymetric indices and three distance measurements to shallowwater topographies. The bathymetric descriptors included (1) median depth, (2) depth coefficient of variation, (3) contour index, and shortest distance to (4) the mainland, (5) the continental shelf-break (200-m isobath), (6) the continental slope (1000-m isobath), and (7) pelagic waters (3000-m isobath). The measurements of shallow water topographies included the shortest distance to: (8) the Cordell Bank seamount, (9) the Farallon Island Archipelago (a breeding colony for auklets and Murres), and (10) Monterey Canyon. We documented two instances of spatial autocorrelation (for Cassin’s auklet and Common Murre) at lags (distances) of 0–3 and 3–9 km, respectively, and accounted for this spatial pattern in analyses of habitat associations. We found similar relationships between cetaceans and bathymetric features at both interannual and weekly time scales. Seabirds revealed both persistent and variable relationships through time. For the resident breeding Murres, we detected an interannual trend in habitat use, with these birds shifting their distribution offshore over time. Our study demonstrates that resident and migrant marine birds and cetaceans are associated with bathymetric features and shallow-water topographies, though responses varied across species and time. In spite of this variability, we contend that bathymetric associations of upper trophic-level predators can help delineate sites of elevated trophic transfer. An understanding of marine productivity and predator aggregation patterns is essential to design ecosystem-level conservation plans for protecting marine habitats and species. D 2004 Elsevier B.V. All rights reserved.
Alexander L Bond - One of the best experts on this subject based on the ideXlab platform.
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the chemical basis of a signal of individual identity shell pigment concentrations track the unique appearance of Common Murre eggs
2019Co-Authors: Mark E Hauber, Alexander L Bond, Amy Lee Kouwenberg, Gregory J Robertson, Erpur S Hansen, Mande Holford, Miri Dainson, Alec B Luro, James DaleAbstract:In group-living species with parental care, the accurate recognition of one's own young is critical to fitness. Because discriminating offspring within a large colonial group may be challenging, progeny of colonial breeders often display familial or individual identity signals to elicit and receive parental provisions from their own parents. For instance, the Common Murre (or Common guillemot: Uria aalge) is a colonially breeding seabird that does not build a nest and lays and incubates an egg with an individually unique appearance. How the shell's physical and chemical properties generate this individual variability in coloration and maculation has not been studied in detail. Here, we quantified two characteristics of the avian-visible appearance of Murre eggshells collected from the wild: background coloration spectra and maculation density. As predicted by the individual identity hypothesis, there was no statistical relationship between avian-perceivable shell background coloration and maculation density within the same eggs. In turn, variation in both sets of traits was statistically related to some of their physico-chemical properties, including shell thickness and concentrations of the eggshell pigments biliverdin and protoporphyrin IX. These results illustrate how individually unique eggshell appearances, suitable for identity signalling, can be generated by a small number of structural mechanisms.
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the chemical basis of a signal of individual identity shell pigment concentrations track the unique appearance of Common Murre eggs
2019Co-Authors: Mark E Hauber, Alexander L Bond, Amy Lee Kouwenberg, Gregory J Robertson, Erpur S Hansen, Mande Holford, Miri Dainson, Alec B Luro, James DaleAbstract:In group-living species with parental care, the accurate recognition of one's own young is critical to fitness. Because discriminating offspring within a large colonial group may be challenging, pr...
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aberrant colouration in the atlantic puffin fratercula arctica the Common Murre uria aalge and the thick billed Murre u lomvia from atlantic canada
2016Co-Authors: Alexander L Bond, Antony W DiamondAbstract:The colour of birds’ plumage and bare parts is an important feature in choice of mate, camouflage, thermoregulation, species recognition, and flight mechanics. Abnormalities in colouration occur in a variety of species and can have important consequences for an individual’s survival and fitness. We present 7 new cases of colouration abnormalities in 3 species of auk (Alcidae) and review previous reports to correctly assign the proper form of abnormality to specimens in museums or photographs. Of the 53 reported colouration abnormalities, we reclassified 42, progressive greying being the most Common (18 or 19 cases out of 42, 43–45%), followed by brown (10/42 cases, 24%), in addition to 6 cases of melanism, 4 of dilution, 2 of partial leucism, and 1 likely somatic mutation. Properly describing the form of colour abnormality improves our understanding of the frequency, causes, and consequences of aberrant colouration.
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Diet Changes in Breeding Herring Gulls (Larus argentatus) in Witless Bay, Newfoundland and Labrador, Canada, over 40 Years
2016Co-Authors: Alexander L BondAbstract:Abstract. The diets of gulls (Laridae) can have consequences for reproductive success, chick growth, and survival, yet there have been no quantitative assessments in eastern Newfoundland since the early 1970s. The diet of Herring Gulls (Larus argentatus) was examined through regurgitated prey items and pellets on Gull Island, Witless Bay, Newfoundland and Labrador, Canada, in 2012, and compared with similar data from 1970–1971. There was a significant shift in Herring Gull diet composition from blue mussels (Mytilus edulis) and capelin (Mallotus villosus) in the 1970s to garbage and Common Murre (Uria aalge) eggs in 2012. Delays in capelin spawning and the large increase in breeding Common Murres on Gull Island are likely factors influencing Herring Gull diet. Garbage, which includes human food scraps as well as plastic debris, now constitutes the single largest diet item for Herring Gulls, corresponding with a global increase in plastic pollution. The consistently low contribution of fisheries discards s...
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thickness of Common Murre uria aalge eggshells in atlantic canada
2014Co-Authors: Donald W Piriehay, Alexander L BondAbstract:Reported values for eggshell thickness in Common Murre ( Uria aalge ) are few, and even fewer since the decline in use of organochlorine pesticides and other environmental pollutants that caused significant thinning of shells. The eggshells of Common Murres and Thick-billed Murres ( Uria lomvia ) are among the thickest and heaviest, proportionately, of any bird and this represents a non-trivial maternal investment. We measured the length and breadth of Common Murre eggs collected from Machias Seal Island, New Brunswick, in 2006, and Gull Island, Newfoundland and Labrador, in 2012, and we measured the thickness of the eggshells. Shell thickness was not related to egg size or volume, and it varied in individual eggs. The shells of Common Murre eggs from Machias Seal Island (mean and standard deviation [SD] (0.767, SD 0.078 mm) and Gull Island (0.753, SD 0.057 mm) were significantly thicker than any previously reported value and among the thickest of all birds. Such thickness is likely a result of nesting on rock substrate with no nesting material and, perhaps, high breeding densities.
Alexandria B Boehm - One of the best experts on this subject based on the ideXlab platform.
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quantitative pcr assays to detect whales rockfish and Common Murre environmental dna in marine water samples of the northeastern pacific
2020Co-Authors: Elizabeth A Andruszkiewicz, Kevan M Yamahara, Collin J Closek, Alexandria B BoehmAbstract:Monitoring aquatic species by identification of environmental DNA (eDNA) is becoming more Common. To obtain quantitative eDNA datasets for individual species, organism-specific quantitative PCR (qPCR) assays are required. Here, we present detailed methodology of qPCR assay design and testing, including in silico, in vitro, and in vivo testing, and comment on the challenges associated with assay design and performance. We use the presented methodology to design assays for three important marine organisms Common in the California Current Ecosystem (CCE): humpback whale (Megaptera novaeangliae), shortbelly rockfish (Sebastes jordani), and Common Murre (Uria aalge). All three assays have excellent sensitivity and high efficiencies ranging from 92% to 99%. However, specificities of the assays varied from species-specific in the case of Common Murre, genus-specific for the shortbelly rockfish assay, and broadly whale-specific for the humpback whale assay, which cross-amplified with other two other whale species, including one in a different family. All assays detected their associated targets in complex environmental water samples.
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quantitative pcr assays to detect humpback whale megaptera novaeangliae shortbelly rockfish sebastes jordani and Common Murre uria aalge in marine water samples
2020Co-Authors: Elizabeth A Andruszkiewicz, Kevan M Yamahara, Collin J Closek, Alexandria B BoehmAbstract:Monitoring aquatic species by identification of environmental DNA (eDNA) is becoming more Common. In order to obtain quantitative datasets for individual species, species-specific quantitative PCR (qPCR) assays are required. Here, we present detailed methodology of qPCR assay design and testing, including in silico, in vitro, and in vivo testing, and comment on the challenges associated with assay design and performance. We use the presented methodology to design assays for three important marine organisms Common in the California Current Ecosystem (CCE): humpback whale (Megaptera novaeangliae), shortbelly rockfish (Sebastes jordani), and Common Murre (Uria aalge). All three assays have excellent sensitivity and high efficiencies ranging from 92% to 99%. However, specificities of the assays varied from species-specific in the case of Common Murre to the genus-specific shortbelly rockfish assay, to the humpback whale assay which cross-amplified with other two other whale species, including one in a different family. All assays detected their associated targets in complex environmental water samples.
Elizabeth A Andruszkiewicz - One of the best experts on this subject based on the ideXlab platform.
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quantitative pcr assays to detect whales rockfish and Common Murre environmental dna in marine water samples of the northeastern pacific
2020Co-Authors: Elizabeth A Andruszkiewicz, Kevan M Yamahara, Collin J Closek, Alexandria B BoehmAbstract:Monitoring aquatic species by identification of environmental DNA (eDNA) is becoming more Common. To obtain quantitative eDNA datasets for individual species, organism-specific quantitative PCR (qPCR) assays are required. Here, we present detailed methodology of qPCR assay design and testing, including in silico, in vitro, and in vivo testing, and comment on the challenges associated with assay design and performance. We use the presented methodology to design assays for three important marine organisms Common in the California Current Ecosystem (CCE): humpback whale (Megaptera novaeangliae), shortbelly rockfish (Sebastes jordani), and Common Murre (Uria aalge). All three assays have excellent sensitivity and high efficiencies ranging from 92% to 99%. However, specificities of the assays varied from species-specific in the case of Common Murre, genus-specific for the shortbelly rockfish assay, and broadly whale-specific for the humpback whale assay, which cross-amplified with other two other whale species, including one in a different family. All assays detected their associated targets in complex environmental water samples.
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quantitative pcr assays to detect humpback whale megaptera novaeangliae shortbelly rockfish sebastes jordani and Common Murre uria aalge in marine water samples
2020Co-Authors: Elizabeth A Andruszkiewicz, Kevan M Yamahara, Collin J Closek, Alexandria B BoehmAbstract:Monitoring aquatic species by identification of environmental DNA (eDNA) is becoming more Common. In order to obtain quantitative datasets for individual species, species-specific quantitative PCR (qPCR) assays are required. Here, we present detailed methodology of qPCR assay design and testing, including in silico, in vitro, and in vivo testing, and comment on the challenges associated with assay design and performance. We use the presented methodology to design assays for three important marine organisms Common in the California Current Ecosystem (CCE): humpback whale (Megaptera novaeangliae), shortbelly rockfish (Sebastes jordani), and Common Murre (Uria aalge). All three assays have excellent sensitivity and high efficiencies ranging from 92% to 99%. However, specificities of the assays varied from species-specific in the case of Common Murre to the genus-specific shortbelly rockfish assay, to the humpback whale assay which cross-amplified with other two other whale species, including one in a different family. All assays detected their associated targets in complex environmental water samples.
Antony W Diamond - One of the best experts on this subject based on the ideXlab platform.
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aberrant colouration in the atlantic puffin fratercula arctica the Common Murre uria aalge and the thick billed Murre u lomvia from atlantic canada
2016Co-Authors: Alexander L Bond, Antony W DiamondAbstract:The colour of birds’ plumage and bare parts is an important feature in choice of mate, camouflage, thermoregulation, species recognition, and flight mechanics. Abnormalities in colouration occur in a variety of species and can have important consequences for an individual’s survival and fitness. We present 7 new cases of colouration abnormalities in 3 species of auk (Alcidae) and review previous reports to correctly assign the proper form of abnormality to specimens in museums or photographs. Of the 53 reported colouration abnormalities, we reclassified 42, progressive greying being the most Common (18 or 19 cases out of 42, 43–45%), followed by brown (10/42 cases, 24%), in addition to 6 cases of melanism, 4 of dilution, 2 of partial leucism, and 1 likely somatic mutation. Properly describing the form of colour abnormality improves our understanding of the frequency, causes, and consequences of aberrant colouration.
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mercury concentrations in seabird tissues from machias seal island new brunswick canada
2009Co-Authors: Alexander L Bond, Antony W DiamondAbstract:Mercury is a pervasive environmental contaminant, the anthropogenic portion of which is increasing globally, and in northeastern North America in particular. Seabirds frequently are used as indicators of the marine environment, including mercury contamination. We analysed paired samples for total mercury (Hg) concentrations in feathers and blood from adult and chick, albumen, and lipid-free yolk of seven seabirds breeding on Machias Seal Island, New Brunswick, Canada — Arctic Tern (Sterna paradisaea), Atlantic Puffin (Fratercula arctica), Common Eider (Somateria mollissima), Common Murre (Uria aalge), Common Tern (Sterna hirundo), Leach's Storm-petrel (Oceanodroma leucorhoa), and Razorbill (Alca torda). We also used stable-isotope ratios of carbon (δ13C), and nitrogen (δ15N) to evaluate the relationship between carbon source and trophic position and mercury. We found high Hg concentrations across tissue types in Leach's Storm-petrels, and Razorbills, with lower concentrations in other species, the lowest being in Common Eiders. Storm-petrels prey on mesopelagic fish that accumulate mercury, and Razorbills feed on larger, older fish that bioaccumulate heavy metals. Biomagnification of Hg, or the increase in Hg concentration with trophic position as measured by δ15N, was significant and greater in albumen than other tissues, whereas in other tissues, δ15N explained little of the overall variation in Hg concentration. Hg concentrations in egg components are higher on Machias Seal Island than other sites globally and in the Gulf of Maine region, but only for some species. Further detailed investigations are required to determine the cause of this trend.