| differences in prey selection and behaviour during self-feeding and chick provisioning in rhinoceros auklets. | we determined whether a marine diving bird, the rhinoceros auklet, cerorhinca monocerata, used different foraging behaviour and collected different prey items for its young than when feeding itself. foraging behaviour was determined by conducting visual scans, and prey items were sampled by collecting fish delivered to chicks and by collecting fish where auklets were self-feeding, which was verified by two other sources of information. adult auklets ate small fish (59.1+/-0.5 mm, n=547), includi ... | 1999 | 10512659 |
| trace metals, stable isotope ratios, and trophic relations in seabirds from the north pacific ocean. | trace elements including mercury, cadmium, selenium, and stable nitrogen isotope ratios (sigma15n) were measured in tissues of pacific seabirds. two species of albatross (diomedea immutabilis, diomedea nigripes), four species of shearwaters (puffinus bulleri, puffinus carneipes, puffinus griseus, puffinus tenuirostris), northern fulmar (fulmarus glacialis), and horned puffin (fratercula corniculata) were collected opportunistically by an experimental fishery in the north pacific ocean. two speci ... | 2005 | 16445091 |
| swim speeds and stroke patterns in wing-propelled divers: a comparison among alcids and a penguin. | in diving birds, the volume and resulting buoyancy of air spaces changes with dive depth, and hydrodynamic drag varies with swim speed. these factors are important in the dive patterns and locomotion of alcids that use their wings both for aerial flight and underwater swimming and of penguins that use their wings only for swimming. using small data-loggers on free-ranging birds diving to 20-30 m depth, we measured depth at 1 hz and surge and heave accelerations at 32-64 hz of four species of alc ... | 2006 | 16547294 |
| phylogenetic relationships within the alcidae (charadriiformes: aves) inferred from total molecular evidence. | the alcidae is a unique assemblage of northern hemisphere seabirds that forage by "flying" underwater. despite obvious affinities among the species, their evolutionary relationships are unclear. we analyzed nucleotide sequences of 1,045 base pairs of the mitochondrial cytochrome b gene and allelic profiles for 37 allozyme loci in all 22 extant species. trees were constructed on independent and combined data sets using maximum parsimony and distance methods that correct for superimposed changes. ... | 1996 | 8587501 |
| temporal trends of perfluoroalkyl substances (pfas) in eggs of coastal and offshore birds: increasing pfas levels associated with offshore bird species breeding on the pacific coast of canada and wintering near asia. | perfluoroalkyl substances (pfas) such as perfluoroalkyl carboxylates (pfcas) and perfluoroalkyl sulfonates (pfsas) have become virtually ubiquitous throughout the environment, and, based on laboratory studies, have known toxicological consequences. various national and international voluntary phase-outs and restrictions on these compounds have been implemented over the last 10 to 15 years. in the present study, we examine trends (1990/1991-2010/2011) in aquatic birds (ancient murrelet, synthlibo ... | 2015 | 25989421 |
| contamination status and accumulation characteristics of metals and a metalloid in birds on teuri island, hokkaido, japan. | teuri island, hokkaido in japan is an important place for seabirds breeding. we measured the concentrations of heavy metals (hg, cd, cr, co, ni, cu, zn, and pb) and a metalloid (as) in rhinoceros auklet (cerorhinca monocerata) (n = 7), thick-billed murre (uria lomvia) (n = 2), spectacled guillemot (cepphus carbo) (n = 6), slaty-backed gull (larus schistisagus) (n = 15), jungle crow (corvus macrorhynchos) (n = 3), japanese anchovy (engraulis japonica) (n = 6) and atka mackerel (pleurogrammus azon ... | 2014 | 25282956 |
| stable isotopes link diet to avian yolk carotenoid allocation: a comparative study of five auk species (charadriiformes: alcidae). | the allocation of important but environmentally limited nutrients, such as carotenoids, often represents a trade-off between homeostasis and reproduction. however, key questions remain about how diet and species traits influence carotenoid allocation. we studied yolk carotenoid profiles and yolk color in relation to trophic level (based on delta(15)n values) in five species of seabirds belonging to the family alcidae: common murre (uria aalge), pigeon guillemot (cepphus columba), cassin's auklet ... | 2010 | 20210648 |
| feather corticosterone reveals stress associated with dietary changes in a breeding seabird. | changes in climate and anthropogenic pressures might affect the composition and abundance of forage fish in the world's oceans. the junk-food hypothesis posits that dietary shifts that affect the quality (e.g., energy content) of food available to marine predators may impact their physiological state and consequently affect their fitness. previously, we experimentally validated that deposition of the adrenocortical hormone, corticosterone, in feathers is a sensitive measure of nutritional stress ... | 2015 | 26664674 |
| spatial and temporal trends in brominated flame retardants in seabirds from the pacific coast of canada. | polybrominated diphenyl ethers (pbdes) and hexabromocyclododecane (hbcdd) are bioaccumulative flame retardants. pbdes increased in many ecosystems during the late 20th century, but recently have declined in some environments. to examine trends in the northern pacific, we analysed pbdes, hbcdd and carbon and nitrogen stable isotopes (δ13c and δ15n) to account for dietary effects in archived eggs of three seabird species from british columbia, canada, 1990-2011 (rhinoceros auklets, cerorhinca mono ... | 2014 | 25194271 |
| using seabird habitat modeling to inform marine spatial planning in central california's national marine sanctuaries. | understanding seabird habitat preferences is critical to future wildlife conservation and threat mitigation in california. the objective of this study was to investigate drivers of seabird habitat selection within the gulf of the farallones and cordell bank national marine sanctuaries to identify areas for targeted conservation planning. we used seabird abundance data collected by the applied california current ecosystem studies program (access) from 2004-2011. we used zero-inflated negative bin ... | 2013 | 23967206 |
| applicability of the doubly labelled water method to the rhinoceros auklet, cerorhinca monocerata. | the doubly labelled water (dlw) method is an isotope-based technique that is used to measure the metabolic rates of free-living animals. we validated the dlw method for measuring metabolic rates in five rhinoceros auklets (cerorhinca monocerata) compared with simultaneous measurements using the respirometric method. we calculated the co(2) production rate of four auklets (mean initial body mass: 552 g±36 s.d.) injected with dlw, using the one- and two-pool models. the metabolic rate during the 2 ... | 2012 | 23213394 |
| ecological factors differentially affect mercury levels in two species of sympatric marine birds of the north pacific. | in 2003 and 2004, we measured mercury concentrations and δ¹⁵n and δ¹³c values in the whole blood of adults of two species of seabirds, cassin's auklet (ptychoramphus aleuticus) and rhinoceros auklet (cerorhinca monocerata), during their prelaying, incubation, and provisioning periods. we also collected whole blood from the offspring of both seabirds. among prey items, δ¹⁵n values were higher in fish than in crustaceans, while δ¹³c did not vary systematically between prey types. mercury concentra ... | 2011 | 21276602 |
| yolk carotenoids and stable isotopes reveal links among environment, foraging behavior and seabird breeding success. | nutrients that are limited in availability, such as carotenoids, are potentially involved in trade-offs between homeostasis and reproduction. despite their importance, factors that affect the capacity of female birds to meet their carotenoid requirements are poorly understood. we used delta(15)n stable isotope analysis to relate foraging behavior to yolk carotenoid deposition in two seabirds, cassin's auklet (ptychoramphus aleuticus) and rhinoceros auklet (cerorhinca monocerata), during each of ... | 2010 | 20397031 |
| disentangling effects of growth and nutritional status on seabird stable isotope ratios. | a growing number of studies suggest that an individual's physiology affects its carbon and nitrogen stable isotope signatures, obscuring a signal often assumed to be only a reflection of diet and foraging location. we examined effects of growth and moderate food restriction on red blood cell (rbc) and feather delta(15)n and delta(13)c in rhinoceros auklet chicks (cerorhinca monocerata), a piscivorous seabird. chicks were reared in captivity and fed either control (75 g/day; n = 7) or ~40% restri ... | 2009 | 18975007 |
| are yolk androgens adjusted to environmental conditions? a test in two seabirds that lay single-egg clutches. | it is widely believed that female birds strategically allocate androgens to yolk in the manner that best equips offspring for feeding conditions during their development. because most avian studies have focused on multi-egg clutch species, and interpreted results within the framework of sibling competition, we still know little about how yolk androgens might be allocated in direct response to environmental conditions. most oceanic birds are long-lived and lay single-egg clutches, and their breed ... | 2008 | 18577385 |
| assimilation efficiency of rhinoceros auklet (cerorhinca monocerata) chicks fed japanese anchovy (engraulis japonicus) and japanese sand lance (ammodytes personatus). | we investigated the assimilation efficiency (ae) of a piscivorous alcid, rhinoceros auklet (cerorhinca monocerata), chicks when fed japanese anchovy (engraulis japonicus) and japanese sand lance (ammodytes personatus), which are their main prey species. the assimilation efficiency corrected for nitrogen retention (nr) of the chicks fed sand lance (81.6%) was significantly higher than those fed anchovy (78.0%). the values of assimilation efficiencies for both fish species are similar to those of ... | 2004 | 15471686 |
| alcataenia fraterculae sp. n. from the horned puffin, fratercula corniculata (naumann), alcataenia cerorhincae sp. n. from the rhinoceros auklet, cerorhinca monocerata (pallas), and alcataenia larina pacifica ssp. n. (cestoda: dilepididae) in the north pacific basin. | three cestodes representing two species of the genus alcataenia spasskaia, 1971 and a subspecies of alcataenia larina (krabbe, 1869) are described. alcataenia fraterculae sp. n. (cestoda: dilepididae) was found in horned puffins, fratercula corniculata (naumann), and other species of seabirds from localities in the western aleutian islands, gulf of alaska, bering sea, and chukchi sea. alcataenia cerorhincae sp. n. is described from the rhinoceros auklet, cerorhinca monocerata (pallas) in the eas ... | 1984 | 6486621 |
| size- and condition-dependent predation: a seabird disproportionately targets substandard individual juvenile salmon. | selection of prey that are small and in poor body condition is a widespread phenomenon in terrestrial predator-prey systems and may benefit prey populations by removing substandard individuals. similar selection is widely assumed to operate in aquatic systems. indeed, size-selective predation is a longstanding and central tenet of aquatic food web theory. however, it is not known if aquatic predators select prey based on their condition or state, compared to their size. surprisingly, no comparab ... | 2016 | 27145620 |
| persistent organic pollutants in forage fish prey of rhinoceros auklets breeding in puget sound and the northern california current. | organochlorine contaminants in upper trophic-level consumers inhabiting puget sound are consistently higher than in those species inhabiting other west coast locations. we analyzed persistent organic pollutants (pops) in the six most common fish prey of rhinoceros auklets breeding on protection island (puget sound), tatoosh island (wa coast), and destruction island (wa coast). wet-weight concentrations of pops ranged widely (pcbs: 1.6-25.0 ng/g; ddts: 0.2-56.0 ng/g; pbdes:<loq-49.0 ng/g), but ov ... | 2014 | 25103902 |
| feather corticosterone reveals developmental stress in seabirds. | in nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (cort). recent studies indicate that cort is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. the current hypothesis predicts that, assuming a constant rate of feather growth, elevated cort circulating in the blood corresponds to higher levels of cort in feather tissue, but experimental ev ... | 2014 | 24744418 |
| plastic ingestion in marine-associated bird species from the eastern north pacific. | in addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. we examined the stomach contents of 20 bird species collected from the coastal waters of the eastern north pacific, a region known to have high levels of plastic pollution. we observed no evidence of plastic ingestion in rhinoceros auklet, marbled murrelet, ancient murrelet or pigeon guillemot, and low levels in common murre (2.7% incidence rate). sm ... | 2013 | 23683586 |
| geolocator tagging links distributions in the non-breeding season to population genetic structure in a sentinel north pacific seabird. | we tested the hypothesis that segregation in wintering areas is associated with population differentiation in a sentinel north pacific seabird, the rhinoceros auklet (cerorhinca monocerata). we collected tissue samples for genetic analyses on five breeding colonies in the western pacific ocean (japan) and on 13 colonies in the eastern pacific ocean (california to alaska), and deployed light-level geolocator tags on 12 eastern pacific colonies to delineate wintering areas. geolocator tags were de ... | 2020 | 33166314 |
| of 11 candidate steroids, corticosterone concentration standardized for mass is the most reliable steroid biomarker of nutritional stress across different feather types. | measuring corticosterone in feathers has become an informative tool in avian ecology, enabling researchers to investigate carry-over effects and responses to environmental variability. few studies have, however, explored whether corticosterone is the only hormone expressed in feathers and is the most indicative of environmental stress. essential questions remain as to how to compare hormone concentrations across different types of feathers and whether preening adds steroids, applied after feathe ... | 2019 | 31695898 |
| biotransport of metallic trace elements from marine to terrestrial ecosystems by seabirds. | physical systems, such as currents and winds, have traditionally been considered responsible for transporting contaminants. although evidence is mounting that animals play a role in this process through their movements, we still know little about how such contaminant biotransport occurs and the extent of effects at deposition sites. in the present study, we address this question by studying how rhinoceros auklets (cerorhinca monocerata), a seabird that occurs in immense colonies (∼300 000 pairs ... | 2019 | 30284322 |
| detection of bisgaard taxon 40 in rhinoceros auklets ( cerorhinca monocerata) with pneumonia and septicemia from a mortality event in washington, usa. | we isolated bisgaard taxon 40 from rhinoceros auklets ( cerorhinca monocerata) with pneumonia and septicemia from washington, us, found dead in 2016. previously isolated only from the respiratory tract of a gull (laridae), little is known about its pathogenic potential and whether it acts as a primary or opportunistic pathogen. | 2019 | 30096034 |
| two forage fishes as potential conduits for the vertical transfer of microfibres in northeastern pacific ocean food webs. | we assessed the potential role played by two vital northeastern pacific ocean forage fishes, the pacific sand lance (ammodytes personatus) and pacific herring (clupea pallasii), as conduits for the vertical transfer of microfibres in food webs. we quantified the number of microfibres found in the stomachs of 734 sand lance and 205 herring that had been captured by an abundant seabird, the rhinoceros auklet (cerorhinca monocerata). sampling took place on six widely-dispersed breeding colonies in ... | 2018 | 29655068 |
| ontogeny of surface texture of limb bones in modern aquatic birds and applicability of textural ageing. | despite its importance in various disciplines, a general method to assess ontogenetic ages of skeletal and fossil specimens has been lacking for birds. although the textural ageing method was formulated to assess relative ontogenetic ages of specimens from inspection of bone surface textures, the exact correspondence of surface textures to ontogenetic stages has not yet been clear. in this study, bone surface textures of six major limb bones (humerus, ulna, carpometacarpus, femur, tibiotarsus, a ... | 2018 | 29195009 |