Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the influence of oxygen and carbon dioxide on diving behaviour of tufted ducks, aythya fuligula. | while optimal diving models focus on the diver's oxygen (o(2)) stores as the predominant factor influencing diving behaviour, many vertebrate species surface from a dive before these stores are exhausted and may commence another dive well after their o(2) stores have been resaturated. this study investigates the influence of hypoxia and also hypercapnia on the dive cycle of tufted ducks, aythya fuligula, in terms of surface duration and dive duration. the birds were trained to surface into a res ... | 2003 | 13130424 |
| delayed implantation in the grey seal, halichoerus grypus (fab.). | 1956 | 13358804 | |
| variation in the secondary sex-ratio of the grey seal halichoerus grypus (fab.) during the breeding season. | 1961 | 13695938 | |
| features of reproduction in the grey seal. | 1964 | 14178134 | |
| experimental trichinella infection in seals. | the susceptibility of seals to infection with trichinella nativa and the cold tolerant characteristics of muscle larvae in seal meat were evaluated. two grey seals, halichoerus grypus, were inoculated with 5000 (100 larvae/kg) t. nativa larvae and two grey seals with 50000 (1000 larvae/kg). one seal from each dose group and two control seals were killed at 5 and 10 weeks post-inoculation (p.i.). at 5 weeks p.i., infection was established in both low and high dose seals with mean larval densities ... | 2003 | 14572509 |
| polychlorinated biphenyls and organochlorine pesticides in baltic and atlantic gray seal (halichoerus grypus) pups. | organochlorine pollutants (ocs), such as polychlorinated biphenyls (pcbs), ddt, chlordanes (chls), hexachlorobenzene (hcb) and hexachlorocyclohexanes (hchs) were determined in blubber biopsies from free-ranging baltic and atlantic gray seal (halichoerus grypus) pups. well-fed pups from the baltic sea had concentrations of ddt, pcbs, and hchs that were 2 to 10 times higher than in corresponding pups from populations in the atlantic ocean. the oc pattern in the baltic seals differed significantly ... | 2003 | 14587923 |
| bone mineral density in male baltic grey seal (halichoerus grypus). | bone mineral density (mg cm(-3)) was studied in male baltic grey seals (4-23 years of age) by noninvasive computed tomography (pqct). the material was grouped according to year of collection. group a: 1850-1955, a period before the main introduction of organochlorines (ocs); group b: 1965-1985, a period with very high oc contamination; and group c: 1986-1997, a period with decreasing concentrations of ocs. the reproducibility of the measurements was good with a coefficient of variation (cv) rang ... | 2003 | 14627366 |
| comprehensive two-dimensional gas chromatography of the 209 polychlorinated biphenyls. | comprehensive two-dimensional gas chromatography (gc x gc) of the 209 polychlorinated biphenyls (cbs) was carried out using a longitudinally modulated cryogenic system (lmcs) and liquid carbon dioxide as cryogen. the effluent from a non-polar column was modulated and further separated on either a polar or a shape-selective second-dimension column. five gc x gc column combinations were evaluated, with db-xlb as the first column in each case. db-xlb separates more congeners than any other gc colum ... | 2003 | 14650609 |
| determination of atropisomeric and planar polychlorinated biphenyls, their enantiomeric fractions and tissue distribution in grey seals using comprehensive 2d gas chromatography. | high prevalence of uterine occlusions and sterility is found among baltic ringed and grey seal. polychlorinated biphenyls (cbs) are suspected to be the main cause. the cb concentrations are higher in affected than in healthy animals, but the natural variation is considerable. thus, it might be possible to assess the health status of seals by cb analysis. the ratios of chiral compounds (enantiomeric fractions (efs)) such as atropisomeric cbs are of particularinterest, since these may reflect diff ... | 2003 | 14650610 |
| identification and molecular characterization of beta-hemolytic streptococci isolated from harbor seals (phoca vitulina) and grey seals (halichoerus grypus) of the german north and baltic seas. | bacteriological investigations of seals of the german north and baltic seas resulted in the isolation of bacteria of the genus streptococcus belonging to lancefield's serological groups c, f, and l. according to biochemical, serological, and 16s ribosomal dna analysis, the group c and group f streptococci were identified as streptococcus phocae. the group l streptococci could be classified as streptococcus dysgalactiae subsp. dysgalactiae. | 2004 | 14715808 |
| perfluorinated chemicals infiltrate ocean waters: link between exposure levels and stable isotope ratios in marine mammals. | this is the first study to report on concentrations of perfluorinated organochemicals (focs) in marine mammals stranded along the southern north sea coast in relation to stable nitrogen and carbon isotope ratios (delta15n and delta13c). the presence of focs in top predators such as marine mammals would indicate a potential biomagnification of these compounds and their widespread occurrence. liver and kidney tissues of nine marine mammal species have been sampled. among all the measured focs comp ... | 2003 | 14717162 |
| a gray seal's (halichoerus grypus) responses to experimenter-given pointing and directional cues. | a gray seal (halichoerus grypus) was trained to touch a target on its left or right by responding to pointing signals. the authors then tested whether the seal would be able to generalize spontaneously to altered signals. it responded correctly to center pointing and head turning, center upper body turning, and off-center pointing but not to head turning and eye movements alone. the seal also responded correctly to brief ipsilateral and contralateral points from center and lateral positions. poi ... | 2003 | 14717636 |
| lactation in the grey seal. | 1951 | 14825243 | |
| combining demographic, environmental and genetic data to test hypotheses about colonization events in metapopulations. | we describe a method for making inferences about the factors that influence colonization processes in natural populations. we consider the general situation where we have genetic data from a newly colonized population and also from i source populations that may have contributed individuals to the founding group that established the new population. the model assumes that p (biotic/abiotic) factors, g(1), ... ,g(p) may have influenced some individuals in some of the source populations to find a ne ... | 2004 | 15012757 |
| bis(4-chlorophenyl) sulfone (bcps) in swedish marine and fresh water wildlife-a screening study. | bis(4-chlorophenyl) sulfone (bcps) is a high production volume chemical (hpvc) applied in thermostable polymers. bcps has been detected as an environmental contaminant both in europe and in north america but it is still not a commonly studied pollutant. in this study, three baltic sea fish species; herring (clupea harengus), salmon (salmo salar) and perch (perca fluviatilis) from the swedish coast, and one inland fish species, arctic char (salvelinus alpinus), were analysed to screen for the occ ... | 2004 | 15051243 |
| metabolic rates of captive grey seals during voluntary diving. | the energetic cost of diving in marine mammals is a difficult value to derive given the problems of assessing metabolic rate for an animal at sea. nevertheless, it is fundamental to our understanding of the foraging strategies of air-breathers exploiting underwater food sources. we measured the metabolic rates of eight captive grey seals, voluntarily diving in a quasi-natural setting. oxygen consumption during post-dive surface periods was measured using open-flow respirometry, and dive behaviou ... | 2004 | 15073194 |
| mercury and selenium in arctic and coastal seals off the coast of norway. | mercury and selenium concentrations (wet weight) have been determined in samples of liver, kidney and brain of grey seal (halichoerus grypus), harbour seal (phoca vitulina), harp seal (phoca groenlandica) and ringed seal (phoca hispida) caught along the norwegian coast, 114 individuals in all. significant differences have been found in mercury contamination between the 4 species caught in the same coastal area, jarfjord, located at the north-east of the norwegian coast close to the russian borde ... | 1994 | 15091671 |
| an unexpected parallelism between vitamin a and pcbs in seal milk. | bioaccumulating pollutants such as polychlorinated biphenyls (pcbs) induce a range of adverse effects in mammals. vitamin a metabolism is prone to such pollutant disruption which may be particularly harmful for young animals. during lactation, maternal pcbs are transferred to the offspring through the milk. seal milk is very fatty and consequently contains large amounts of these persistent lipophilic contaminants. in the present study, we investigated the relationships between pcbs and vitamins ... | 2004 | 15145227 |
| experimental toxoplasma gondii infection in grey seals (halichoerus grypus). | laboratory-reared animals were used to assess the susceptibility of seals (halichoerus grypus) to toxoplasma gondii infection. four seals were each orally inoculated with 100 or 10,000 oocysts of t. gondii (veg strain), and another 4 seals served as negative controls. occasionally, mild behavioral changes were observed in all inoculated seals but not in control animals. a modified agglutination test revealed the presence of antibodies to t. gondii in sera collected from inoculated seals and mice ... | 2004 | 15165046 |
| patterns of parental relatedness and pup survival in the grey seal (halichoerus grypus). | levels of parental relatedness can affect offspring survival and susceptibility to disease. we investigated parental relatedness of live and dead halichoerus grypus pups between and within island populations and between possible causes of mortality. nine microsatellites were used to calculate internal relatedness (ir) and standardized mean d2. we find that pups with higher than average levels of ir have significantly lower survival and that this varied between island populations and that certain ... | 2004 | 15245408 |
| metabolic regulation in diving birds and mammals. | ducks, fur seals, weddell seals and probably most cetaceans seem to be able to dive and remain aerobic for durations that are consistent with their elevated stores of usable oxygen and their metabolic rate while diving being similar to that when they are resting at the surface of the water. ducks, in fact, have a high metabolic rate while diving, mainly because of their large positive buoyancy, but other species have relatively low buoyancy, are better streamlined and use lift-based rather than ... | 2004 | 15288601 |
| seroprevalence of toxoplasma gondii in canadian pinnipeds. | sera (n = 328) collected from phocids (1995-97) from the east coast of canada, including harp seals (phoca groenlandica), hooded seals (cystophora cristata), grey seals (halichoerus grypus), and harbor seals (phoca vitulina), were diluted 1:25, 1:50, and 1:500 and tested by a modified agglutination test for antibodies to toxoplasma gondii. titers equal to or greater than 1:25 were considered evidence of exposure. grey seal (11/122, 9%), harbor seal (3/34, 9%), and hooded seal (1/60, 2%) had tite ... | 2004 | 15362830 |
| streptococcus halichoeri sp. nov., isolated from grey seals (halichoerus grypus). | phenotypic and phylogenetic studies were performed on six unidentified, gram-positive, catalase-negative, chain-forming streptococcus-like organisms recovered from grey seals. biochemically the six strains were highly related to each other, but they did not appear to correspond to any recognized species of the genus streptococcus. comparative 16s rrna gene sequencing studies confirmed that phylogenetically the strains were members of the genus streptococcus, but sequence divergence values of gre ... | 2004 | 15388740 |
| longevity in the grey seal. | 1950 | 15439136 | |
| demonstration of the deposition and modification of dietary fatty acids in pinniped blubber using radiolabelled precursors. | radioisotopes are commonly used to study the in vivo metabolism and deposition of dietary fatty acids in adipose tissue. the application of this approach to pinnipeds is problematic because of their large mass and blubber fat content. we have developed a method where labelled lipids can be fed to seals at financially feasible levels, with the radioactivity in individual fatty acids isolated from blubber detected with standard laboratory equipment. a combination of techniques including argentatio ... | 2004 | 15449239 |
| the rate of fertilization in male mating tactics of the polygynous grey seal. | studies using molecular markers have shown that some grey seal males may be gaining success through exhibiting alternative mating tactics. we estimated the probability of fertilization success of grey seal males exhibiting the primary tactic of female defence and one alternative tactic of mating with departing females on sable island, nova scotia, canada, during the breeding seasons of 1997-2002. although the fertilization rate of the primary tactic (27-43%) was greater than that of the alternat ... | 2004 | 15488010 |
| enantiomeric specificity of methylsulfonyl-pcbs and distribution of bis(4-chlorophenyl) sulfone, pcb, and dde methyl sulfones in grey seal tissues. | pcb methyl sulfones (meso2-pcbs) are lipophilic pcb metabolites of which five of the environmentally relevant meta/para pairs are chiral (i.e., exist as atropisomeric pairs). methylsulfonyl-dde (meso2-dde) is a dde metabolite, while bis(4-chlorophenyl) sulfone (bcps) is a commercial monomer used for thermoplastic production. all these sulfones are well-known environmental contaminants. in this study, liver, lung, and adipose tissue in grey seals (halichoerus grypus) from the baltic sea, naturall ... | 2004 | 15506185 |
| absorption of decabromodiphenyl ether and other organohalogen chemicals by grey seals (halichoerus grypus). | an input-output balance study was performed for polybrominated diphenyl ethers, polychlorinated biphenyls and some organochlorine pesticides on three captive, juvenile grey seals (halichoerus grypus). the animals were fed a diet of herring for six months, during the last three months of which this study was performed. a supplement of decabromodiphenyl ether was included in the diet during the second month of the study. consistently high absorption (>89%) was observed for all of the chemicals stu ... | 2005 | 15519732 |
| polybrominated diphenyl ethers and selected organochlorine chemicals in grey seals (halichoerus grypus) in the north sea. | blubber samples from grey seal (halichoerus grypus) pups were collected in 1998 through to 2000. twenty four newly weaned pups were sampled in november 1998, 13 of which were re-sampled during their first year of life, between march and december 1999, and an additional 48 and 25 samples (new cohorts) were obtained in 1999 (november-december) and 2000 (may-september) respectively. simgapbde concentrations (sum of di-hxbdes) ranged from 45 to 1500 ng/g lipid, with a geometric mean of 290 ng/g lipi ... | 2005 | 15581937 |
| call usage learning in gray seals (halichoerus grypus). | call usage learning can be demonstrated on 4 different levels: signaling on command, signaling and refraining from signaling on command, responding to a trained stimulus with a signal from a specific signal class, and responding to the playback of any untrained stimulus with one from the same signal class. two young gray seals (halichoerus grypus) were trained successfully to demonstrate the first 2 levels. they also learned to respond to 9 moan stimuli and 9 growl stimuli with vocalizations of ... | 2004 | 15584781 |
| dynamics of blood chylomicron fatty acids in a marine carnivore: implications for lipid metabolism and quantitative estimation of predator diets. | blubber fatty acid(s) (fa) signatures can provide accurate estimates of predator diets using quantitative fa signature analysis, provided that aspects of predator fa metabolism are taken into account. because the intestinal absorption of dietary fa and their incorporation into chylomicrons (the primary transport lipoproteins for dietary fa in the blood) may influence the relationship between fa composition in the diet and adipose tissue, we investigated the metabolism of individual fa at these e ... | 2005 | 15657738 |
| isolation and partial characterization of a parapoxvirus isolated from a skin lesion of a weddell seal. | a solitary skin lesion was found on the neck of a weddell seal (leptonychotes weddellii), chemically immobilized in queen maud land (70 degrees 09's, 05 degrees 22'e) antarctica 2001. the lesion was elevated and 3cm in diameter, consisting of partly fresh and partly necrotic tissue, and proliferative papilloma-like structures were seen. electron microscopy on a biopsy from the lesion revealed typical parapoxvirus particles. polymerase chain reaction (pcr; b2l gene) generated amplicons of approxi ... | 2005 | 15681058 |
| accumulation of dietary organochlorines and vitamins in baltic seals. | we studied the accumulation of polychlorinated biphenyls (pcbs), 1,1,1.trichloro-2,2-bis[p-chlorophenyl]ethane (ddt) and its metabolites, and vitamins a and e in the top levels of the baltic sea food web. the investigation focused on the transfer of contaminants and vitamins to the ringed seal (phoca hispida baltica) and the grey seal (halichoerus grypus) from their main prey species. the trophic level of the seals was investigated using stable isotopes of nitrogen and the results indicated that ... | 2004 | 15769500 |
| thyroid hormone status in gray seal (halichoerus grypus) pups from the baltic sea and the atlantic ocean in relation to organochlorine pollutants. | marine apex predators, such as the gray seal (halichoerus grypus), are exposed to high concentrations of organochlorine (oc) compounds via biomagnification in the food web. these lipophilic pollutants are transferred from the female to her offspring during lactation, and there is particular concern for endocrine disruption in the offspring. herein we examined associations between the blubber concentrations of polychlorinated biphenyls (pcbs), dichlorodiphenyltrichloroethane (ddt) and metabolites ... | 2005 | 15779761 |
| comparison of toxaphene congeners levels in five seal species from eastern canada: what is the importance of biological factors? | environmentally relevant chlorobornanes (chbs) were measured in blubber samples of harbor (phoca vitulina), gray (halichoerus grypus), harp (phoca groenlandica), and hooded seals (cystophora cristata) sampled in different part of the st. lawrence marine ecosystem (slme) and ringed seals (phoca hispida) sampled in the eastern canadian arctic waters. the purpose of this study was to compare the levels of six chbs (parlar-26, -40/-41, -44, -50, and -62) among the five seal species. seal species cou ... | 2005 | 15819196 |
| molecular cloning and expression of leptin in gray and harbor seal blubber, bone marrow, and lung and its potential role in marine mammal respiratory physiology. | leptin is a multifunctional hormone, produced predominantly in adipocytes. it regulates energy balance through its impact on appetite and fat metabolism, and its concentration indicates the size of body fat reserves. leptin also plays a vital role in stretch-induced surfactant production during alveolar development in the fetus. the structure, expression pattern, and role of leptin have not previously been explored in marine mammals. phocid seals undergo cyclical changes in body composition as a ... | 2005 | 15831765 |
| development of the blood and muscle oxygen stores in gray seals (halichoerus grypus): implications for juvenile diving capacity and the necessity of a terrestrial postweaning fast. | to successfully transition from nursing to foraging, phocid seal pups must develop adequate diving physiology within the limited time between birth and their first independent foraging trip to sea. we studied the postpartum development of oxygen stores in gray seals (halichoerus grypus, n=40) to better understand the ontogeny of diving capacity in phocids. hemoglobin (hb), hematocrit (hct), blood volume (bv), and myoglobin (mb) levels in newborn (3 d postpartum [dpp]) and newly weaned (17+/-0.4 ... | 2005 | 15957103 |
| comparison of polychlorinated biphenyl (pcb) induced effects on innate immune functions in harbour and grey seals. | polychlorinated biphenyls (pcbs) are known to have detrimental effects on the innate immune system of several mammalian species. top predators such as marine mammals may be badly affected as pcbs can bioaccumulate in their blubber to high concentrations and previous studies have suggested that harbour seals may be particularly vulnerable to the immunotoxic effects of such contaminants. to investigate the effects of pcbs on innate immune functions in phocid seals, blood samples were collected fro ... | 2005 | 15982755 |
| persistent organic pollutant patterns in grey seals (halichoerus grypus). | the aim of this paper is to examine the patterns of polychlorinated biphenyls (pcb) in the grey seals (halichoerus grypus) from the baltic, northeast and eastern england, and the st. lawrence estuary (canada). in fact, the feeding habits of the ringed seal (phoca hispida) include ingestion of major quantities of benthic crustaceans that might cause observed differences obtained in pcbs, whereas the grey seal feed mainly on fish. the profile (percent in mixture) of polychlorinated biphenyls (pcb) ... | 2005 | 15992598 |
| factors influencing the radiative surface temperature of grey seal (halichoerus grypus) pups during early and late lactation. | the aim of this study was to examine the variation in body surface temperature of grey seal (halichoerus grypus) pups throughout lactation in response to different environmental conditions. radiative surface temperatures (t (r), degrees c) of pups were measured on the isle of may (56 degrees 11'n, 02 degrees 33'w), southeast scotland from 29 october to 25 november 2003. records were obtained from a total of 60 pups (32 female and 28 male) from three different pupping sites during early and late ... | 2005 | 16001186 |
| identification and real-time pcr quantification of phocine distemper virus from two colonies of scottish grey seals in 2002. | the north sea european harbour seal (phoca vitulina) population has endured two phocine distemper virus (pdv) epidemics in 1988 and 2002. the grey seal (halichoerus grypus) is a sympatric seal species that shows little or no mortality from pdv. two scottish grey seal breeding colonies were sampled for evidence of pdv infection approximately 2 months after the peak of the 2002 epidemic. in both colonies, a proportion of mothers (13/109) and pups (6/84) tested positive for pdv in their leukocytes. ... | 2005 | 16099915 |
| temporal trend of bis(4-chlorophenyl) sulfone, methylsulfonyl-dde and -pcbs in baltic guillemot (uria aalge) egg 1971-2001--a comparison to 4,4'-dde and pcb trends. | the dynamics of organohalogen contaminants and their metabolites are best studied over time by analysis of biota at high trophic levels. in this study, time trends, 1971-2001, of bis(4-chlorophenyl) sulfone (bcps) and of methylsulfonyl-substituted metabolites of pcbs and 4,4'-dde, were investigated in eggs of guillemot (uria aalge) hatching in the baltic proper. temporal trends of pcbs, trans-nonachlor, beta-hch, 4,4'-ddt, and 4,4'-dde were also assessed. tris(4-chlorophenyl) methane (tcpme), a ... | 2006 | 16225974 |
| identification and characterization of tandem repeats in exon iii of dopamine receptor d4 (drd4) genes from different mammalian species. | in this study we have identified and characterized dopamine receptor d4 (drd4) exon iii tandem repeats in 33 public available nucleotide sequences from different mammalian species. we found that the tandem repeat in canids could be described in a novel and simple way, namely, as a structure composed of 15- and 12- bp modules. tandem repeats composed of 18-bp modules were found in sequences from the horse, zebra, onager, and donkey, asiatic bear, polar bear, common raccoon, dolphin, harbor porpoi ... | 2005 | 16332176 |
| catellicoccus marimammalium gen. nov., sp. nov., a novel gram-positive, catalase-negative, coccus-shaped bacterium from porpoise and grey seal. | two strains of an unknown gram-positive, catalase-negative, facultatively anaerobic, coccus-shaped bacterium, originating from a porpoise and a grey seal, were characterized using phenotypic, biochemical and molecular phylogenetic methods. chemical studies revealed the presence of a cell-wall murein based on l-lysine (type l-lys-gly-d-asp) and a dna g+c content of 38 mol%. comparative 16s rrna gene sequencing showed that this unidentified coccus-shaped organism formed a hitherto unknown subline ... | 2006 | 16449452 |
| seasonal variation in the metabolic rate and body composition of female grey seals: fat conservation prior to high-cost reproduction in a capital breeder? | many animals rely on stored energy through periods of high energy demand or low energy availability or both. a variety of mechanisms may be employed to attain and conserve energy for such periods. wild grey seals demonstrate seasonal patterns of energy storage and foraging behaviour that appear to maximize the allocation of energy to reproduction--a period characterized by both high energy demand and low food availability. we examined seasonal patterns in resting rates of oxygen consumption as a ... | 2006 | 16506041 |
| cell cultures from marine mammals. | cell cultures grown from the gray seal halichoerus grypus and the dolphin lagenorhynchus obliquidens support the replication of several human viruses. further evidence indicates the gray seal kidney cell culture has transformed. | 1970 | 16512163 |
| identification of highly brominated analogues of q1 in marine mammals. | three novel halogenated organic compounds (hocs) have been identified in the blubber of marine mammals from coastal new england with the molecular formulae c(9)h(3)n(2)br(6)cl, c(9)h(3)n(2)br(7), and c(9)h(4)n(2)br(5)cl. they were identified using high and low resolution gas chromatography mass spectrometry (gcms) and appear to be highly brominated analogues of q1, a heptachlorinated hoc suspected to be naturally produced. these compounds were found in atlantic white sided dolphin (lagenorhynchu ... | 2006 | 16517037 |
| photo-identification, site fidelity, and movement of female gray seals (halichoerus grypus) between haul-outs in the baltic sea. | the growing gray seal population in the baltic sea has led to increased conflicts with fisheries. despite limited data on gray seal ecology, management measures, such as culling, have been implemented recently. we studied movements and site fidelity of baltic gray seals using mark-recapture analysis based on photographic identification of individuals (photo-id). seals were photographed at the major summer haul-out sites. profile photographs of the head and neck were matched using purpose-written ... | 2005 | 16521839 |
| the 1988 and 2002 phocine distemper virus epidemics in european harbour seals. | we present new and revised data for the phocine distemper virus (pdv) epidemics that resulted in the deaths of more than 23 000 harbour seals phoca vitulina in 1988 and 30,000 in 2002. on both occasions the epidemics started at the danish island of anholt in central kattegat, and subsequently spread to adjacent colonies in a stepwise fashion. however, this pattern was not maintained throughout the epidemics and new centres of infection appeared far from infected populations on some occasions: in ... | 2006 | 16532603 |
| stomach temperature telemetry reveals temporal patterns of foraging success in a free-ranging marine mammal. | 1. we studied feeding frequency in free-ranging grey seals using stomach temperature telemetry to test if previously reported sex differences in the diving, movement and diet were reflected in the temporal pattern of foraging success. 2. data were retrieved from 21 of 32 grey seals from 1999 to 2001, totalling 343 days and 555 feeding events, with individual record length varying from 2 to 40 days (mean: 16.33 +/- 2.67 days/seal). 3. seals fed on 57.8 +/- 6.46% of days sampled and had an average ... | 2006 | 16637994 |
| finding fathers: spatio-temporal analysis of paternity assignment in grey seals (halichoerus grypus). | molecular studies of pinniped breeding systems exhibit a broad range of agreement and disagreement with observational indices of male breeding success. grey seal studies have reported considerable discrepancies between genetic and behavioural paternity measures that have been interpreted as evidence of previously unidentified male strategies and/or tactics. therefore, these studies have the power to fundamentally alter our perceptions of mating systems. however, other pinniped studies exhibit no ... | 2006 | 16689909 |
| incorporating movement into models of grey seal population dynamics. | 1. one of the most difficult problems in developing spatially explicit models of population dynamics is the validation and parameterization of the movement process. we show how movement models derived from capture-recapture analysis can be improved by incorporating them into a spatially explicit metapopulation model that is fitted to a time series of abundance data. 2. we applied multisite capture-recapture analysis techniques to photo-identification data collected from female grey seals at the ... | 2006 | 16689946 |
| pcr amplification of species specific sequences of 16s rdna and 16s-23s rdna intergenic spacer region for identification of streptococcus phocae. | streptococcus phocae, a bacterial pathogen of seals, could reliably be identified by pcr amplification using oligonucleotide primers designed according to species specific segments of the previously sequenced 16s rrna gene and the 16s-23s rdna intergenic spacer region of this species. the pcr mediated assay allowed an identification of s. phocae isolated from harbor and gray seals and from atlantic salmons. no cross-reaction could be observed with 13 different other streptococcal species and sub ... | 2008 | 16793248 |
| metabolism of dietary cetoleic acid (22:1n-11) in mink (mustela vison) and gray seals (halichoerus grypus) studied using radiolabeled fatty acids. | cetoleic acid (22:1n-11) is a good indicator of diet in marine predators and has proven to be an important fatty acid (fa) when using adipose tissue fa composition to study diet in marine mammals and seabirds. feeding studies have shown that 22:1 isomers are predictably underrepresented in adipose tissue relative to diet, implying that metabolism within the predator strongly influences the relationship between the level of these fas in diet and adipose tissue. fully understanding such metabolic ... | 2006 | 16826508 |
| [echinophthirius horridus (olfers, 1816) (anoplura) rare parasite on seals]. | e. horridus of the anoplura species was noted for the second time in poland on a grey seal. | 2001 | 16894733 |
| sexual segregation of seasonal foraging habitats in a non-migratory marine mammal. | many animal species segregate by sex. such segregation may be social in nature, or ecological, or both. grey seals (halichoerus grypus), like many large mammals, are sexually size dimorphic. in size dimorphic species, allometric differences in morphology, metabolic rate and reproductive costs are likely. such differences may require the sexes to use different foraging strategies or different habitats. to investigate sexual segregation of habitat in grey seals, we used satellite tracks from 95 (m ... | 2006 | 16928634 |
| reproductive performance in grey seals: age-related improvement and senescence in a capital breeder. | 1. three hypotheses have been advanced to account for age-related improvement in performance: the selection hypothesis predicts improved due to the loss of lower quality phenotypes, the constraint hypothesis predicts individuals improve function, and the restraint hypothesis predicts younger individuals forego or reduce effort because of mortality risks. a decline in age-related performance (i.e. senescence) is predicted by mutation accumulation, antagonistic pleiotropy and disposable soma (wear ... | 2006 | 17032366 |
| relatedness of streptococcus equi subsp. zooepidemicus strains isolated from harbour seals (phoca vitulina) and grey seals (halichoerus grypus) of various origins of the north sea during 1988-2005. | the present study was designed to identify 15 beta-hemolytic streptococci isolated during a period between 1988 and 2005 from nine harbour seals and six grey seals from various origins of the north sea. all isolates were identified as streptococcus equi subsp. zooepidemicus. the bacteria were additionally investigated for relatedness by restriction fragment length polymorphism analysis of pcr amplified 16s-23s rdna intergenic spacer region and gene szp and by macrorestriction analysis of chromos ... | 2007 | 17169506 |
| in vitro and in vivo replication of seal gammaherpesviruses in cells of multiple species. | phocid herpesvirus virus type 2 (phhv-2), a putative gammaherpesvirus of seals, has been isolated from harbor seals (phoca vitulina) and grey seals (halichoerus grypus). in the present study, different phhv-2 isolates were shown to have a broad in vitro tropism for various cell types from several mammalian species. inbred mice and two species of non-human primates proved to be susceptible to experimental infection with phhv-2. the development of myoepitheliomas and spleen hyperplasia upon cyclos ... | 2007 | 17194610 |
| continued decline of an atlantic cod population: how important is gray seal predation? | the continental shelf ecosystem on the eastern scotian shelf (ess) has experienced drastic changes. once common top predators are a small fraction of their historical abundance, and much of the current community structure is now dominated by pelagic fishes and invertebrates. embedded within this food web, atlantic cod and gray seal populations have recently exhibited nearly opposite trends. since 1984, cod populations have decreased exponentially at a rate averaging 17% per year, whereas gray se ... | 2006 | 17205904 |
| note on the capture of the grey seal, halichoerus grypus, on the coasts of fife and forfar. | 1870 | 17230861 | |
| on an edentulous condition of the skull of the grey seal. | 1873 | 17230978 | |
| halichoerus grypus: the grey seal: observations on its external appearances and visceral anatomy. | 1896 | 17232201 | |
| halichoerus grypus: the grey seal: observations on its external appearances and visceral anatomy. | 1896 | 17232208 | |
| linking movement, diving, and habitat to foraging success in a large marine predator. | establishing where and when predators forage is essential to understanding trophic interactions, yet foraging behavior remains poorly understood in large marine carnivores. we investigated the factors leading to foraging success in gray seals (halichoerus grypus) in the northwest atlantic in the first study to use simultaneous deployments of satellite transmitters, time depth recorders, and stomach-temperature loggers on a free-ranging marine mammal. thirty-two seals were each fitted with the th ... | 2006 | 17249234 |
| sex differences in grey seal diet reflect seasonal variation in foraging behaviour and reproductive expenditure: evidence from quantitative fatty acid signature analysis. | 1. intraspecific variation in diet can be an important component of a species niche breadth. we tested the hypothesis that sex differences in seasonal foraging behaviour and energy storage of sexually size dimorphic grey seals halichoerus grypus (fabrisius 1971) are reflected in differences in the diet and niche breadth. diet composition was estimated for 496 adult (226 males, 270 females) and 91 juvenile (46 males/45 females; all 6 months old) grey seals sampled between 1993 and 2000 using quan ... | 2007 | 17439466 |
| the impact of climatic variation on the opportunity for sexual selection. | many studies have demonstrated influences of climatic variation on a variety of ecological processes, however, its impact on the potent evolutionary force of sexual selection has largely been ignored. the intensity of sexual selection is a fundamental parameter in animal populations, which depends upon the degree of polygamy and will probably be influenced by the impact of local climatic variation upon 'environmental potential for polygamy'. here, we provide evidence of a direct effect of local ... | 2007 | 17443953 |
| eat now, pay later? evidence of deferred food-processing costs in diving seals. | seals may delay costly physiological processes (e.g. digestion) that are incompatible with the physiological adjustments to diving until after periods of active foraging. we present unusual profiles of metabolic rate (mr) in grey seals measured during long-term simulation of foraging trips (4-5 days) that provide evidence for this. we measured extremely high mrs (up to almost seven times the baseline levels) and high heart rates during extended surface intervals, where the seals were motionless ... | 2007 | 17443975 |
| first compound-specific chlorine-isotope analysis of environmentally-bioaccumulated organochlorines indicates a degradation-relatable kinetic isotope effect for ddt. | compound-specific chlorine-isotope analysis (csia-cl) of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-ddt) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (p,p'-dde) in blubber from baltic grey seal (halichoerus grypus) was performed in order to investigate if a kinetic isotope effect (kie) could be observed concomitant to environmental degradation of ddt. the delta(37)cl of p,p'-ddt and p,p'-dde were -0.69 +/- 0.21 per thousand and -2.98 +/- 0.57 per thousand (1s igma, n = 3), respectivel ... | 2007 | 17631944 |
| effects of mass and body composition on fasting fuel utilisation in grey seal pups (halichoerus grypus fabricius): an experimental study using supplementary feeding. | this study used supplementary feeding to test the hypothesis that fuel partitioning during the postweaning fast in grey seal pups is affected by size and composition of energy reserves at weaning, and by extra provisioning. mass and body composition changes were measured during suckling and fasting to investigate the effect of natural differences in energy reserves at weaning on subsequent allocation of fat and protein to energy use. we fed seven pups for 5 days after weaning, to investigate the ... | 2007 | 17704079 |
| underwater sounds of pinnipeds. | descriptions and analyses are presented of underwater sounds made by six species of seals in captivity, zalophus californianus, phoca vitulina, p. (pusa) hispida, p. (pagophilus) groenlandica, halichoerus grypus, and cystophora cristata. the suitability of these very faint sounds for echolocation is discussed. | 1963 | 17742884 |
| [retrospective analysis of two phocine distemper epidemics in the north and baltic seas in 1988 and 2002]. | the relapse of the outbreak of the phocine distemper virus in the danish island of anholt this june, emphasizes the importance of the topic among experts. during the phocine distemper virus (pdv) epidemic in 1988, a total of 23,000 harbour seals (phoca vitulina) died. in 2002 a second outbreak of pdv resulted in the death of more than 30,000 harbor seals. both epidemics originated near the danish island of anholt and spread to adjacent colonies. additional centres of infection were observed in t ... | 2007 | 17763629 |
| how fast does a seal swim? variations in swimming behaviour under differing foraging conditions. | the duration of breath-hold dives and the available time for foraging in submerged prey patches is ultimately constrained by oxygen balance. there is a close relationship between swim speed and oxygen utilisation, so it is likely that breath-holding divers optimise their speeds to and from the feeding patch to maximise time spent feeding at depth. optimal foraging models suggest that transit swim speed should decrease to minimum cost of transport (mct) speed in deeper and longer duration dives. ... | 2007 | 17766306 |
| evidence for mate fidelity in the gray seal. | colonially breeding gray seals are polygynous. males are larger than females, compete with each other for position among aggregated females, and contribute no parental care. genetic analysis of pups born on the island of north rona, scotland, reveals large numbers of full siblings, although dominant males father disproportionately few of these. this result cannot be explained by mating patterns based solely on male dominance and the spatio-temporal organization of the breeding colony. instead, m ... | 1995 | 17797534 |
| in search of virus carriers of the 1988 and 2002 phocine distemper virus outbreaks in european harbour seals. | european harbour seal (phoca vitulina) populations decreased substantially during the phocine distemper virus (pdv) outbreaks of 1988 and 2002. different hypotheses have stated that various seals and terrestrial carnivore species might be the source of infection. to further analyse these hypotheses, grey (halichoerus grypus) and ringed (phoca hispida) seals, polar bears (ursus maritimus) and minks (mustela lutreola) were sampled from the north sea and east greenland coasts between 1988 and 2004 ... | 2008 | 17896075 |
| haematological and biochemical values for grey seal pups (halichoerus grypus) during early rehabilitation. | haematological and biochemical data were collected over a period of six years from grey seal (halichoerus grypus) pups undergoing rehabilitation. pups bled during the first three days were allocated retrospectively to one of seven clinical groups and statistical analyses were carried out on six of these groups (130 pups). compared with reference ranges, all the groups had lower mean packed-cell volumes (pcv), red blood cell (rbc) counts haemoglobin and albumin levels, pups with severe trauma had ... | 2007 | 17906226 |
| revisiting lévy flight search patterns of wandering albatrosses, bumblebees and deer. | the study of animal foraging behaviour is of practical ecological importance, and exemplifies the wider scientific problem of optimizing search strategies. lévy flights are random walks, the step lengths of which come from probability distributions with heavy power-law tails, such that clusters of short steps are connected by rare long steps. lévy flights display fractal properties, have no typical scale, and occur in physical and chemical systems. an attempt to demonstrate their existence in a ... | 2007 | 17960243 |
| phylogeny and divergence of the pinnipeds (carnivora: mammalia) assessed using a multigene dataset. | phylogenetic comparative methods are often improved by complete phylogenies with meaningful branch lengths (e.g., divergence dates). this study presents a dated molecular supertree for all 34 world pinniped species derived from a weighted matrix representation with parsimony (mrp) supertree analysis of 50 gene trees, each determined under a maximum likelihood (ml) framework. divergence times were determined by mapping the same sequence data (plus two additional genes) on to the supertree topolog ... | 2007 | 17996107 |
| the implications of stress on male mating behavior and success in a sexually dimorphic polygynous mammal, the grey seal. | studies on primates and other taxa have shown that the physiological response of an individual to stress reflects their social status. we combined behavioral observations with measures of stress to test the hypothesis that stress is an important physiological determinant of mating behavior and success in the male grey seal. known-age males (n=19) were studied during the breeding seasons of 2004 and 2005 at sable island, canada. the stressor was a capture and restraint period of 35 min and serial ... | 2008 | 18021775 |
| phocid seals, seal lice and heartworms: a terrestrial host-parasite system conveyed to the marine environment. | adaptation of pinnipeds to the marine habitat imposed parallel evolutions in their parasites. ancestral pinnipeds must have harboured sucking lice, which were ancestors of the seal louse echinophthirius horridus. the seal louse is one of the few insects that successfully adjusted to the marine environment. adaptations such as keeping an air reservoir and the ability to hold on to and move on the host were necessary, as well as an adjustment of their life cycle to fit the diving habits of their h ... | 2007 | 18062474 |
| study of the relation between the incidence of uterine leiomyomas and the concentrations of pcb and ddt in baltic gray seals. | exposure to environmental contaminants is believed to be associated with the previously described decrease in the reproduction rate of baltic gray seals. in the present study the prevalence of uterine leiomyomas was investigated in 257 baltic gray seal females examined during 1973-2007, in relation to the levels of polychlorinated biphenyls (pcbs) and dichlorodiphenyltrichloroethane (ddt) in baltic biota, using an estimated exposure index. additionally, the proliferative activity in leiomyomas, ... | 2008 | 18187284 |
| bone-related effects of contaminants in seals may be associated with vitamin d and thyroid hormones. | the high levels of polychlorinated biphenyls (pcbs) and ddt in gray seal (halichoerus grypus) and ringed seal (phoca hispida botnica) in the baltic sea have been associated with pathological disruptions, including bone lesions and reproductive failures. the underlying environmental and toxicological mechanisms leading to these pathological changes are not yet fully understood. the present study investigated the relationship between the individual contaminant load and bone- and thyroid-related ef ... | 2008 | 18333671 |
| polybrominated diphenyl ethers (pbdes) in seal populations from eastern and western canada: an assessment of the processes and factors controlling pbde distribution in seals. | polybrominated diphenyl ether (pbde) concentrations were measured in the blubber of five mother-pup pairs of grey seals (halichoerus grypus) from sable island, nova scotia (ns) sampled in 1995 and in 20 harbour seals (phoca vitulina) from british columbia (bc) sampled in 1991-1992. concentrations in maternal grey seals from sable island averaged 112+/-55.2 ng/g lipid (mean+/-s.d.) and were over twice the concentrations measured in their pups; higher brominated pbdes showed a distinct decline in ... | 2008 | 18359511 |
| isolation of lactoferrin from milk of different species: calorimetric and antimicrobial studies. | lactoferrin (lf) is an iron-binding glycoprotein found in different biological fluids of mammals and in neutrophils. it has been proposed to be involved in many functions, including protection from pathogens. in this work, purification of lactoferrin using an ion-exchange chromatography (sp-sepharose) was attempted for the milk of the following animals: sheep (ovis aries), goat (capra hircus), camel (camelus bactrianus), alpaca (lama pacos), elephant (elephas maximus) and grey seal (halichoerus ... | 2008 | 18387837 |
| body condition at weaning affects the duration of the postweaning fast in gray seal pups (halichoerus grypus). | gray seals (halichoerus grypus) undergo a terrestrial postweaning fast (pwf) that depletes energy reserves acquired during the suckling interval. plasticity in pwf duration may ensure that pups of variable body condition depart for sea with adequate energy reserves. to test this hypothesis, we examined body condition of 30 gray seal pups at weaning and monitored their pwf duration. on average, fat accounted for 47.3% +/- 0.7% of their 53.2 +/- 1.3-kg weaning mass. although fasting duration avera ... | 2008 | 18419553 |
| decreasing ice coverage will reduce the breeding success of baltic grey seal (halichoerus grypus) females. | baltic grey seals (halichoerus grypus) alternate between land and ice breeding, depending on ice conditions. we show that the fitness of grey seal females in terms of pup mortality and quality is reduced when breeding on land as compared with ice. the mean preweaning mortality rate on land was 21.1% (range 0% to 31.6%), and correlated with birth density (range 0.5-5.2 pups 100 m(-2)). the mean mortality rate on ice was 1.5%, where the highest density was 0.2 pups 100 m(-2) in particularly dense ... | 2008 | 18488549 |
| monte carlo inference for state-space models of wild animal populations. | summary: we compare two monte carlo (mc) procedures, sequential importance sampling (sis) and markov chain monte carlo (mcmc), for making bayesian inferences about the unknown states and parameters of state-space models for animal populations. the procedures were applied to both simulated and real pup count data for the british grey seal metapopulation, as well as to simulated data for a chinook salmon population. the mcmc implementation was based on tailor-made proposal distributions combined w ... | 2009 | 18565166 |
| using likelihood to test for lévy flight search patterns and for general power-law distributions in nature. | 1. ecologists are obtaining ever-increasing amounts of data concerning animal movement. a movement strategy that has been concluded for a broad variety of animals is that of lévy flights, which are random walks whose step lengths come from probability distributions with heavy power-law tails. 2. the exponent that parameterizes the power-law tail, denoted micro, has repeatedly been found to be within the lévy range of 1 < micro <or= 3. here, we use monte carlo simulations to show that the methods ... | 2008 | 18631370 |
| incidence of brucella species in marine mammals of the german north sea. | in this study, organ samples from 426 common seals phoca vitulina, 298 harbour porpoises phocoena phocoena, 34 grey seals halichoerus grypus and 10 other marine mammals were assessed for the presence of brucella species. forty-seven common seals, 2 harbour porpoises and 1 grey seal were found to be positive for these bacteria. a total of 91 brucella strains were successfully isolated, due to the fact that brucella spp. were found in more than one organ sample in 15 animals. the primary organ in ... | 2008 | 18828563 |
| gas bubbles in seals, dolphins, and porpoises entangled and drowned at depth in gillnets. | gas bubbles were found in 15 of 23 gillnet-drowned bycaught harp (pagophilus groenlandicus), harbor (phoca vitulina) and gray (halichoerus grypus) seals, common (delphinus delphis) and white-sided (lagenorhyncus acutus) dolphins, and harbor porpoises (phocaena phocaena) but in only 1 of 41 stranded marine mammals. cases with minimal scavenging and bloating were chilled as practical and necropsied within 24 to 72 hours of collection. bubbles were commonly visible grossly and histologically in byc ... | 2009 | 19176498 |
| immunotoxicity of polychlorinated biphenyls (pcb) in free-ranging gray seal pups with special emphasis on dioxin-like congeners. | increased pinniped and dolphin mortality rates have led to speculations that persistent pollutants, in particular polychlorinated biphenyls (pcb), are immunomodulatory, making individuals susceptible to infections. the aim of the present study was to investigate effects that pcb may exert on peripheral blood mitogen-induced lymphocyte proliferation responses in free-ranging gray seal (halichoerus grypus) pups from the polluted baltic sea and from the cleaner open waters of the atlantic ocean. t- ... | 2009 | 19184741 |
| distribution patterns suggest biomagnification of halogenated 1'-methyl-1,2'-bipyrroles (mbps). | the halogenated 1'-methyl-1,2'-bipyrroles (mbps) are a suite of marine natural products that have been detected in marine mammals worldwide. although their concentrations are similar to persistent organic pollutants that biomagnify, such as 2,2',4,4',5,5'-hexachlorobiphenyl (cb-153), it is notyet clearthat these natural products also biomagnify. here we analyze mbps and cb-153 isolated from the blubber and liver of marine mammals stranded on the eastern coast of massachusetts. four odontocete sp ... | 2009 | 19209594 |
| metabolic characteristics of the gray seal (halichoerus grypus fabricius, 1791) in early postnatal development. | 2009 | 19341082 | |
| organohalogen contaminants and metabolites in cerebrospinal fluid and cerebellum gray matter in short-beaked common dolphins and atlantic white-sided dolphins from the western north atlantic. | concentrations of several congeners and classes of organohalogen contaminants (ohcs) and/or their metabolites, namely organochlorine pesticides (ocs), polychlorinated biphenyls (pcbs), hydroxylated-pcbs (oh-pcbs), methylsulfonyl-pcbs (meso(2)-pcbs), polybrominated diphenyl ether (pbde) flame retardants, and oh-pbdes, were measured in cerebrospinal fluid (csf) of short-beaked common dolphins (n = 2), atlantic white-sided dolphins (n = 8), and gray seal (n = 1) from the western north atlantic. in ... | 2009 | 19375836 |
| assessing threats to species at risk using stage-structured state-space models: mortality trends in skate populations. | population models are needed to assess the threats to species at risk and to evaluate alternative management actions. data to support modeling is limited for many species at risk, and commonly used approaches generally assume stationary vital rates, a questionable assumption given widespread ecosystem change. we describe a modeling approach that can be applied to time series of length composition data to estimate vital rates and test for changes in these rates. our approach uses stage-structured ... | 2009 | 19688940 |
| infectivity of toxoplasma gondii in northern traditional (country) foods prepared with meat from experimentally infected seals. | serological and clinical evidence of human toxoplasmosis in the canadian arctic indicates a food safety risk associated with the consumption of wild game meat. such meat often is eaten raw or partially cooked in locally prepared traditional (country) foods, but no data have been collected to describe survival of toxoplasma gondii forms in these foods. the muscle of grey seals (halichoerus grypus) experimentally infected with t. gondii oocysts was used to prepare three country foods: igunaq, a fe ... | 2009 | 19722415 |
| exposure to persistent organic pollutants and first-year survival probability in gray seal pups. | many studies have demonstrated that persistent organic pollutants are transferred from mother to pup during lactation in phocid seals, but none have been able to determine the significance of these findings for survivorship. the aim of this study was to investigate the relationship between blubber contaminant concentrations and first-year survival in gray seal pups. a mark-recapture framework was used to estimate survival probabilities and animals were "marked" using novel mobile phone tags. ind ... | 2009 | 19746738 |
| phagocytosis in pup and adult harbour, grey and harp seals. | knowledge on pinniped immunology is still in its infancy. for instance, age-related and developmental aspects of the immune system in pinnipeds need to be better described. the present study examined the phagocytic activity and efficiency of harbour, grey and harp seal leukocytes. in the first part of the study, peripheral blood was collected from captive female harbour seals of various ages. data showed an age-related decrease in phagocytosis in female harbour seals from sub-adult to adulthood. ... | 2010 | 19766324 |
| repeatability in lactation performance and the consequences for maternal reproductive success in gray seals. | in mammals, the most significant maternal effect on offspring growth during lactation is the ability of females to efficiently transfer milk energy to their neonates. however, despite the importance of the transfer of milk energy to both maternal and offspring fitness, nothing is known about the extent to which variation among females may be attributed to differences in individual quality or environmental variation in natural populations. we measured repeatability over multiple lactation periods ... | 2009 | 19769129 |
| comparative sensitivity of harbour and grey seals to several environmental contaminants using in vitro exposure. | in this study, we investigated the effects of cadmium chloride (cdcl(2)), mercury chloride (hgcl(2)), methylmercury chloride (ch(3)hgcl), and pcbs on lymphocyte proliferation in phocids. pbmcs isolated from harbour and grey seals were exposed in vitro to varying concentrations of contaminants. a reduction of viability occurred when cells were exposed to 10(-4)m hgcl(2) or ch(3)hgcl or to 50ppm of aroclor 1254. in both grey and harbour seals, t-lymphocyte proliferation was suppressed when their c ... | 2010 | 19945719 |