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Patrick Pomeroy - One of the best experts on this subject based on the ideXlab platform.
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coping styles in capital breeders modulate behavioural trade offs in time allocation assessing fine scale activity budgets in lactating grey seals Halichoerus Grypus using accelerometry and heart rate variability
Behavioral Ecology and Sociobiology, 2020Co-Authors: Courtney R Shuert, Patrick Pomeroy, Sean D TwissAbstract:Balancing time allocation among competing behaviours is an essential part of energy management for all animals. However, trade-offs in time allocation may vary according to the sex of the individual, their age, and even underlying physiology. During reproduction, higher energetic demands and constrained internal resources place greater demand on optimizing these trade-offs insofar that small adjustments in time-activity may lead to substantial effects on an individual’s limited energy budget. The most extreme case is found in animals that undergo capital breeding, where individuals fast for the duration of each reproductive episode. We investigated potential underlying drivers of time-activity and describe aspects of trade-offs in time-activity in a wild, capital breeding pinniped, the grey seal Halichoerus Grypus, during the lactation period. For the first time, we were able to access full 24-h activity budgets across the core duration of lactation as well as characterize how aspects of stress-coping styles influence time allocation through the use of animal-borne accelerometers and heart rate monitors in situ. We found that there was a distinct trade-off in time activity between time spent Resting and Alert (vigilance). This trade-off varied with the pup’s development, date, and maternal stress-coping style as indicated by a measure of heart rate variability, rMSSD. In contrast, time spent Presenting/Nursing did not vary across the duration of lactation given the variables tested. We suggest that while mothers balance time spent conserving resources (Resting) against time expending energy (Alert), they are also influenced by the inherent physiological drivers of stress-coping styles. How animals apportion their time among different behaviours is key to their success. These trade-offs should be finely balanced to avoid unnecessary energy expenditure. Here, we examine how grey seal mothers balance their activity patterns during the short, but energetically demanding, period of pup-rearing. Animal-borne accelerometers provided a uniquely detailed and continuous record of activity during pup-rearing for 38 mothers. We also used heart rate monitors to provide measures of each individual’s stress-coping style. We found that mothers balance time Resting against remaining Alert while time Presenting/Nursing was largely independent of all factors measured. Stress-coping styles were found to drive the balancing and variation of all behaviours. This novel indication that differences in personality-like traits may drive whole activity budgets should be considered when assessing trade-offs in time allocation across a much wider variety of species.
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high oxytocin infants gain more mass with no additional maternal energetic costs in wild grey seals Halichoerus Grypus
Psychoneuroendocrinology, 2019Co-Authors: Kelly J Robinson, Sean D Twiss, Neil Hazon, Patrick PomeroyAbstract:Abstract Maximising infant survival requires secure attachments and appropriate behaviours between parents and offspring. Oxytocin is vital for parent-offspring bonding and behaviour. It also modulates energetic balance and neural pathways regulating feeding. However, to date the connections between these two areas of the hormone’s functionality are poorly defined. We demonstrate that grey seal (Halichoerus Grypus) mothers with high oxytocin levels produce pups with high oxytocin levels throughout lactation, and show for the first time a link between endogenous infant oxytocin levels and rates of mass gain prior to weaning. High oxytocin infants gained mass at a greater rate without additional energetic cost to their mothers. Increased mass gain in infants was not due to increased nursing, and there was no link between maternal mass loss rates and plasma oxytocin concentrations. Increased mass gain rates within high oxytocin infants may be due to changes in individual behaviour and energy expenditure or oxytocin impacting on tissue formation. Infancy is a crucial time for growth and development, and our findings connect the oxytocin driven mechanisms for parent-infant bonding with the energetics underlying parental care. Our study demonstrates that oxytocin release may connect optimal parental or social environments with direct physiological advantages for individual development.
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maternal oxytocin is linked to close mother infant proximity in grey seals Halichoerus Grypus
PLOS ONE, 2015Co-Authors: Kelly J Robinson, Sean D Twiss, Neil Hazon, Patrick PomeroyAbstract:Maternal behaviour is a crucial component of reproduction in all mammals; however the quality of care that mothers give to infants can vary greatly. It is vital to document variation in maternal behaviour caused by the physiological processes controlling its expression. This underlying physiology should be conserved throughout reproductive events and should be replicated across all individuals of a species; therefore, any correlates to maternal care quality may be present across many individuals or contexts. Oxytocin modulates the initiation and expression of maternal behaviour in mammals; therefore we tested whether maternal plasma oxytocin concentrations correlated to key maternal behaviours in wild grey seals (Halichoerus Grypus). Plasma oxytocin concentrations in non-breeding individuals (4.3 ±0.5 pg/ml) were significantly lower than those in mothers with dependent pups in both early (8.2 ±0.8 pg/ml) and late (6.9 ±0.7 pg/ml) lactation. Maternal plasma oxytocin concentrations were not correlated to the amount of nursing prior to sampling, or a mother’s nursing intensity throughout the dependant period. Mothers with high plasma oxytocin concentrations stayed closer to their pups, reducing the likelihood of mother-pup separation during lactation which is credited with causing starvation, the largest cause of pup mortality in grey seals. This is the first study to link endogenous oxytocin concentrations in wild mammalian mothers with any type of maternal behaviour. Oxytocin’s structure and function is widely conserved across mammalian mothers, including humans. Defining the impact the oxytocin system has on maternal behaviour highlights relationships that may occur across many individuals or species, and such behaviours heavily influence infant development and an individual’s lifetime reproductive success.
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patterns of parental relatedness and pup survival in the grey seal Halichoerus Grypus
Molecular Ecology, 2004Co-Authors: William Amos, Patrick Pomeroy, Sean D Twiss, K Bean, Tim Coulson, I L BoydAbstract: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 d 2 . 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 loci contributed to the effect more than others. Although, there were no significant differences between causes of mortality, peritonitis, infection and stillborn had the highest levels of IR. These results provide evidence that parental relatedness is an important determinant of pre-weaning pup survival in the grey seal and that this may vary with cause of mortality given a larger sample size.
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expansion of a grey seal Halichoerus Grypus breeding colony changes in pupping site use at the isle of may scotland
Journal of Zoology, 2000Co-Authors: Patrick Pomeroy, Sean D Twiss, C D DuckAbstract:Until the mid 1970s only a few grey seal Halichoerus Grypus pups were born each year on the Isle of May, Scotland, but 1408 pups were born there in 1994. We examined changes in overall site use, individual pupping site fidelity and success in relation to local population density and topography. The area of the island used by seals for breeding has increased as the population increased. Between 1988 and 1994 an index of the proportion of the island's northern area occupied by seals increased from 0.48 to 0.65, while the average population density in these occupied areas decreased over the same period. Although seals have begun to breed in southern parts of the island that were unused previously, other apparently suitable breeding areas on the island remain vacant. Fine scale digital elevation models were constructed using a GIS to evaluate the topographic characteristics of occupied areas and assign topographic ‘costs’ to areas used by seals for breeding on the Isle of May. Seals were associated generally with areas close to the numerous access points from the sea. New areas occupied in the later years of the study had a higher topographical ‘cost’ than the traditional sites. Thus, in an expanding colony such as the Isle of May, areas colonized early in the colony's history were those close to access points and/or standing water and at low elevations. Subsequent expansion resulted in an increase in the areas occupied by seals, but these newly colonized areas were less suitable, and their occupiers were subject to increased topographic ‘costs’. Pup mortality rates were similar in areas of high and low breeding density. Aggressive behaviour between breeding females is the likely mechanism which acts to limit local animal density. Mothers marked at the Isle of May since 1987 returned there to breed with few exceptions, and most females that returned were faithful to their previous pupping sites (median distance between sites used in consecutive breeding seasons = 25 m). Site fidelity persisted even when a previous pupping was unsuccessful and most individuals' pupping locations did not change gradually with time. Comparison with other colonies suggests that the spatial scale of site fidelity is related to the scale of topographic variation within the breeding site.
D. J. Boness - One of the best experts on this subject based on the ideXlab platform.
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reproductive behaviour of the grey seal Halichoerus Grypus on sable island nova scotia
Journal of Zoology, 2009Co-Authors: D. J. Boness, H JamesAbstract:We describe an unusual mating system, observed in a land-breeding colony of Grey seal, Halichoerus Grypus, in the western Atlantic. Males and females begin to visit the breeding beach about a week before the season begins, but none stay ashore for long until the first pup is born. The cows are gregarious, probably return to the same part of the beach to give birth from one year to the next, and tend to remain in the general vicinity of the birth site during their two and a half week sojourn ashore. Within these limits, however, they are quite mobile, and the size, location and composition of the temporary aggregations which they form vary from one day to the next. The cows become thinner and more sedentary as oestrus approaches, but otherwise they give no overt signs of receptivity. The males do not defend territories, nor do they form dominance hierarchies. Instead, they compete for tenure, the right to remain within the shifting population of females. Tenured bulls directly test the receptivity of nearby cows from time to time, and they continually manoeuvre in ways which maximize their chances of being next to cows which are either in oestrus or likely to become so in the near future. Bulls which fail to establish themselves amongst females try to intercept cows as they are leaving for the sea at the end of their season, but their reproductive success, estimated in several ways, is significantly lower than that of bulls with tenure. The system would be adaptive for seals which breed on the pack ice, but it is unique amongst land-breeding pinnipeds. If, as some circumstantial evidence suggests, Grey seals were originally pack-ice breeders, the persistence of such a system in a land-breeding colony raises some interesting questions about the plasticity of mating behaviour.
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body condition at weaning affects the duration of the postweaning fast in gray seal pups Halichoerus Grypus
Physiological and Biochemical Zoology, 2008Co-Authors: Shawn R Noren, D. J. Boness, Sara J Iverson, Jim I Mcmillan, Don W BowenAbstract:Abstract 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 \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $47.3\% \pm 0.7\% $ \end{document} of their \documentclass{aast...
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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
Physiological and Biochemical Zoology, 2005Co-Authors: Shawn R Noren, Sara J Iverson, D. J. BonessAbstract: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 DPP) pups were among the lowest measured across age classes. During the pups' terrestrial postweaning fast (PWF), Hb, Hct, mass-specific BV, and Mb increased by 28%, 21%, 13%, and 29%, respectively, resulting in a 35% increase in total body mass-specific oxygen stores and a 23% increase in calculated aerobic dive limit (CADL). Although Hb and Hct levels at the end of the PWF were nearly identical to those of yearlings, total body mass-specific oxygen stores and CADL of weaned pups departing for sea were only 66%-67% and 32%-62%, respectively, of those for yearlings and adult females. The PWF represents an integral component of the physiological development of diving capacity in phocids; however, newly independent phocids still appear to have limited diving capabilities at the onset of foraging.
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Mother-pup vocal recognition in the grey seal (Halichoerus Grypus) of Sable Island, Nova Scotia, Canada
Journal of Zoology, 2000Co-Authors: Samantha Mcculloch, D. J. BonessAbstract:Parental recognition of offspring would be expected to evolve among densely populated species in which parental investment is large, and separations of the mother±pup pair are frequent. Although otariids present a well-developed system of mutual vocal recognition, evidence in phocids is weak. Furthermore, allo-suckling is prevalent in some species and may re¯ect confusion over the identity of pups. The vocalizations of grey seal Halichoerus Grypus pups have been found to be stereotyped and individually distinctive on the Isle of May, Scotland. However, playback experiments showed that mothers fail to discriminate between the vocalizations of their pup and a non-®lial pup. Moreover, widespread allosuckling was observed. In contrast, grey seals on Sable Island, Nova Scotia, a population reproductively isolated from that of the Isle of May, show very little allo-suckling. This may re¯ect the presence of a recognition system that does not seem to be present on the Isle of May. During the 1999 breeding season on Sable Island, vocalizations of grey seal pups were recorded and playback experiments carried out to determine whether female grey seals respond differently to the playback of vocalizations of their own pup, a familiar pup and an unfamiliar pup. Grey seal mothers were found to make signi®cantly more head turns and body movements towards the loudspeaker during the playback of their own pup call than during the playback of a familiar or unfamiliar pup call. In addition, there was no evidence of an effect of pup age. This suggests that female grey seals can discriminate between pup calls using the stereotyped and individually distinctive vocalizations of their pup, and that different selective pressures may be in operation between the Sable Island and Isle of May colonies.
Ailsa J Hall - One of the best experts on this subject based on the ideXlab platform.
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seroprevalence of toxoplasma gondii in north eastern atlantic harbor seal phoca vitulina vitulina and grey seal Halichoerus Grypus
Veterinary Parasitology, 2011Co-Authors: Oscar Cabezon, Ailsa J Hall, J P Dubey, Cecile Vincent, M Pabon, Ignacio Garciabocanegra, S AlmeriaAbstract:Antibodies to Toxoplasma gondii were determined in serum samples from 47 grey seals (Halichoerus Grypus) and 56 harbor seals (Phoca vitulina vitulina) from the Atlantic coasts of United Kingdom and France. Antibodies to T. gondii assayed by the modified agglutination test (MAT) were found in 14 (13.6%; IC95%: 7.0–20.2) of 103 seals tested, with titres of 1:25 in 13 seals and 1:50 in 1 seal. Seroprevalence against T. gondii (MAT 1:25 or higher) was significantly higher in grey seals (23.4%) compared to harbor seals (5.4%). No significant differences were found between seroprevalence against T. gondii and sex, age or geographical locations. These results show natural exposure of European harbor and grey seals to T. gondii oocysts in the Atlantic Ocean. To the best of our knowledge, this is the first serological survey of T. gondii in European grey and harbor seals.
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absorption of decabromodiphenyl ether and other organohalogen chemicals by grey seals Halichoerus Grypus
Environmental Pollution, 2005Co-Authors: Gareth O Thomas, Simon Moss, Lillemor Asplund, Ailsa J HallAbstract: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 studied, whereas work on other animals has generally shown high (>80%) net absorption at log KOW < 6, dropping towards higher log KOW, and very low absorption of decabromodiphenyl ether. The half-life of decabromodiphenyl ether in blood was estimated to be between 8.5 and 13 days. Measurable concentrations of decabromodiphenyl ether were detected in seal blubber at the end of the study, indicating that this chemical can be stored in adipose and may bioaccumulate. Current understanding of the mechanism of absorption of organohalogen chemicals and the potential for accumulation of decabromodiphenyl ether will need reassessing in the light of these results. Decabromodiphenyl ether is absorbed effectively from the diet by grey seals, and can be stored in the blubber even after exposure ceases.
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polybrominated diphenyl ethers and selected organochlorine chemicals in grey seals Halichoerus Grypus in the north sea
Chemosphere, 2005Co-Authors: Olgaioanna Kalantzi, Ailsa J Hall, Gareth O Thomas, Kevin C JonesAbstract:Abstract 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. ∑PBDE concentrations (sum of Di-HxBDEs) ranged from 45 to 1500 ng/g lipid, with a geometric mean of 290 ng/g lipid. BDE 47 dominated the congener profile, followed by BDEs 100, 99, 153 and 154. ∑PCB concentrations (sum of 41 congeners) ranged from 100 to 93 000 ng/g lipid, with a geometric mean of 4600 ng/g lipid, with CB congeners 153, 138 and 180 making up 84% of the total PCB concentrations. The predominant OC pesticides were p,p′-DDE (geometric mean = 860 ng/g lipid, range = 160–3800 ng/g lipid) and p,p′-DDT (geometric mean = 120 ng/g lipid, range = 30–670 ng/g lipid). No significant differences were found between males and females, probably due to the young age of the animals. Significant decreases (P
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isolation of two cytochrome p450 cdnas cyp1a1 and cyp1a2 from harp seal phoca groenlandica and grey seal Halichoerus Grypus
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2002Co-Authors: Rachel E Tilley, Graham D Kemp, Ikuko Teramitsu, Ailsa J HallAbstract:Two cytochrome P450 (CYP), CYP1A1 and CYP1A2, cDNA sequences have been isolated and cloned from harp seal (Phoca groenlandica) and grey seal (Halichoerus Grypus). EROD, a model substrate for CYP1A, and heterologous antibodies have been employed as a biomarker in marine mammals, however the CYP1A sequences have not been characterised in these two seal species. mRNA was used as the template in RT-PCR, rather than DNA as this indicates transcription of the CYP1A gene in these seal species exposed to environmental contaminants. Harp and grey seal CYP1A1 amino acid sequences exhibited >99% identity and the CYP1A2 sequences were >98% identical. Phylogenetic analyses of the two seal species with other mammalian, and avian CYP1A sequences, showed the CYP1A1 and CYP1A2 sequences clustered with corresponding sequences in other mammalian species. The closest sequences to the seal CYP1As was dog CYP1A. The CYP1A sequence information presented in this study has provided the necessary data for the future production of species-specific probes for the use as biomarkers of environmental contaminant exposure.
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congener specific exposure of grey seal Halichoerus Grypus pups to chlorinated biphenyls during lactation
Canadian Journal of Fisheries and Aquatic Sciences, 1996Co-Authors: Patrick Pomeroy, Ailsa J Hall, Kevin C Jones, Nicholas J L Green, M J Walton, John HarwoodAbstract:Nous avons mesure l'exposition totale et quotidienne de jeunes phoques gris (Halichoerus Grypus) a 25 congeneres de biphenyle chlore (BC) presents dans le lait des meres a l'ile de May (Ecosse) en 1990, 1991 et 1992. L'exposition totale de 36 petits nes de 13 femelles differentes variait entre 8,8 et 58,9 mg; les congeneres UICPA CB-153 et CB-138 etaient les composantes principales dans le lait, ou ils representaient 42,1% de l'exposition totale aux BC. La quantite de lait consommee chaque jour par les petits et la teneur en lipides de ce lait augmentaient pendant la lactation. En consequence, l'exposition quotidienne aux BC a augmente fortement pendant la premiere moitie de la periode d'allaitement de 18 jours. Il y avait des differences significatives entre les femelles dans les concentrations de BC dans le lait et dans la contribution relative des differents congeneres a l'exposition totale aux BC. Lorsqu'on eliminait les effets des variations entre femelles, on observait des changements significatifs dans les concentrations de BC moins chlores pendant la lactation et d'une annee a l'autre. On peut estimer de facon precise l'exposition d'un petit phoque gris aux BC si l'on connait l'identite de sa mere, sa masse au moment du sevrage et la concentration de BC dans un echantillon de lait preleve vers la fin de l'allaitement.
Sean D Twiss - One of the best experts on this subject based on the ideXlab platform.
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coping styles in capital breeders modulate behavioural trade offs in time allocation assessing fine scale activity budgets in lactating grey seals Halichoerus Grypus using accelerometry and heart rate variability
Behavioral Ecology and Sociobiology, 2020Co-Authors: Courtney R Shuert, Patrick Pomeroy, Sean D TwissAbstract:Balancing time allocation among competing behaviours is an essential part of energy management for all animals. However, trade-offs in time allocation may vary according to the sex of the individual, their age, and even underlying physiology. During reproduction, higher energetic demands and constrained internal resources place greater demand on optimizing these trade-offs insofar that small adjustments in time-activity may lead to substantial effects on an individual’s limited energy budget. The most extreme case is found in animals that undergo capital breeding, where individuals fast for the duration of each reproductive episode. We investigated potential underlying drivers of time-activity and describe aspects of trade-offs in time-activity in a wild, capital breeding pinniped, the grey seal Halichoerus Grypus, during the lactation period. For the first time, we were able to access full 24-h activity budgets across the core duration of lactation as well as characterize how aspects of stress-coping styles influence time allocation through the use of animal-borne accelerometers and heart rate monitors in situ. We found that there was a distinct trade-off in time activity between time spent Resting and Alert (vigilance). This trade-off varied with the pup’s development, date, and maternal stress-coping style as indicated by a measure of heart rate variability, rMSSD. In contrast, time spent Presenting/Nursing did not vary across the duration of lactation given the variables tested. We suggest that while mothers balance time spent conserving resources (Resting) against time expending energy (Alert), they are also influenced by the inherent physiological drivers of stress-coping styles. How animals apportion their time among different behaviours is key to their success. These trade-offs should be finely balanced to avoid unnecessary energy expenditure. Here, we examine how grey seal mothers balance their activity patterns during the short, but energetically demanding, period of pup-rearing. Animal-borne accelerometers provided a uniquely detailed and continuous record of activity during pup-rearing for 38 mothers. We also used heart rate monitors to provide measures of each individual’s stress-coping style. We found that mothers balance time Resting against remaining Alert while time Presenting/Nursing was largely independent of all factors measured. Stress-coping styles were found to drive the balancing and variation of all behaviours. This novel indication that differences in personality-like traits may drive whole activity budgets should be considered when assessing trade-offs in time allocation across a much wider variety of species.
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high oxytocin infants gain more mass with no additional maternal energetic costs in wild grey seals Halichoerus Grypus
Psychoneuroendocrinology, 2019Co-Authors: Kelly J Robinson, Sean D Twiss, Neil Hazon, Patrick PomeroyAbstract:Abstract Maximising infant survival requires secure attachments and appropriate behaviours between parents and offspring. Oxytocin is vital for parent-offspring bonding and behaviour. It also modulates energetic balance and neural pathways regulating feeding. However, to date the connections between these two areas of the hormone’s functionality are poorly defined. We demonstrate that grey seal (Halichoerus Grypus) mothers with high oxytocin levels produce pups with high oxytocin levels throughout lactation, and show for the first time a link between endogenous infant oxytocin levels and rates of mass gain prior to weaning. High oxytocin infants gained mass at a greater rate without additional energetic cost to their mothers. Increased mass gain in infants was not due to increased nursing, and there was no link between maternal mass loss rates and plasma oxytocin concentrations. Increased mass gain rates within high oxytocin infants may be due to changes in individual behaviour and energy expenditure or oxytocin impacting on tissue formation. Infancy is a crucial time for growth and development, and our findings connect the oxytocin driven mechanisms for parent-infant bonding with the energetics underlying parental care. Our study demonstrates that oxytocin release may connect optimal parental or social environments with direct physiological advantages for individual development.
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maternal oxytocin is linked to close mother infant proximity in grey seals Halichoerus Grypus
PLOS ONE, 2015Co-Authors: Kelly J Robinson, Sean D Twiss, Neil Hazon, Patrick PomeroyAbstract:Maternal behaviour is a crucial component of reproduction in all mammals; however the quality of care that mothers give to infants can vary greatly. It is vital to document variation in maternal behaviour caused by the physiological processes controlling its expression. This underlying physiology should be conserved throughout reproductive events and should be replicated across all individuals of a species; therefore, any correlates to maternal care quality may be present across many individuals or contexts. Oxytocin modulates the initiation and expression of maternal behaviour in mammals; therefore we tested whether maternal plasma oxytocin concentrations correlated to key maternal behaviours in wild grey seals (Halichoerus Grypus). Plasma oxytocin concentrations in non-breeding individuals (4.3 ±0.5 pg/ml) were significantly lower than those in mothers with dependent pups in both early (8.2 ±0.8 pg/ml) and late (6.9 ±0.7 pg/ml) lactation. Maternal plasma oxytocin concentrations were not correlated to the amount of nursing prior to sampling, or a mother’s nursing intensity throughout the dependant period. Mothers with high plasma oxytocin concentrations stayed closer to their pups, reducing the likelihood of mother-pup separation during lactation which is credited with causing starvation, the largest cause of pup mortality in grey seals. This is the first study to link endogenous oxytocin concentrations in wild mammalian mothers with any type of maternal behaviour. Oxytocin’s structure and function is widely conserved across mammalian mothers, including humans. Defining the impact the oxytocin system has on maternal behaviour highlights relationships that may occur across many individuals or species, and such behaviours heavily influence infant development and an individual’s lifetime reproductive success.
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patterns of parental relatedness and pup survival in the grey seal Halichoerus Grypus
Molecular Ecology, 2004Co-Authors: William Amos, Patrick Pomeroy, Sean D Twiss, K Bean, Tim Coulson, I L BoydAbstract: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 d 2 . 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 loci contributed to the effect more than others. Although, there were no significant differences between causes of mortality, peritonitis, infection and stillborn had the highest levels of IR. These results provide evidence that parental relatedness is an important determinant of pre-weaning pup survival in the grey seal and that this may vary with cause of mortality given a larger sample size.
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expansion of a grey seal Halichoerus Grypus breeding colony changes in pupping site use at the isle of may scotland
Journal of Zoology, 2000Co-Authors: Patrick Pomeroy, Sean D Twiss, C D DuckAbstract:Until the mid 1970s only a few grey seal Halichoerus Grypus pups were born each year on the Isle of May, Scotland, but 1408 pups were born there in 1994. We examined changes in overall site use, individual pupping site fidelity and success in relation to local population density and topography. The area of the island used by seals for breeding has increased as the population increased. Between 1988 and 1994 an index of the proportion of the island's northern area occupied by seals increased from 0.48 to 0.65, while the average population density in these occupied areas decreased over the same period. Although seals have begun to breed in southern parts of the island that were unused previously, other apparently suitable breeding areas on the island remain vacant. Fine scale digital elevation models were constructed using a GIS to evaluate the topographic characteristics of occupied areas and assign topographic ‘costs’ to areas used by seals for breeding on the Isle of May. Seals were associated generally with areas close to the numerous access points from the sea. New areas occupied in the later years of the study had a higher topographical ‘cost’ than the traditional sites. Thus, in an expanding colony such as the Isle of May, areas colonized early in the colony's history were those close to access points and/or standing water and at low elevations. Subsequent expansion resulted in an increase in the areas occupied by seals, but these newly colonized areas were less suitable, and their occupiers were subject to increased topographic ‘costs’. Pup mortality rates were similar in areas of high and low breeding density. Aggressive behaviour between breeding females is the likely mechanism which acts to limit local animal density. Mothers marked at the Isle of May since 1987 returned there to breed with few exceptions, and most females that returned were faithful to their previous pupping sites (median distance between sites used in consecutive breeding seasons = 25 m). Site fidelity persisted even when a previous pupping was unsuccessful and most individuals' pupping locations did not change gradually with time. Comparison with other colonies suggests that the spatial scale of site fidelity is related to the scale of topographic variation within the breeding site.
Ursula Siebert - One of the best experts on this subject based on the ideXlab platform.
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liver histopathology of baltic grey seals Halichoerus Grypus over three decades
Environment International, 2020Co-Authors: Britta Schmidt, Christian Sonne, Dominik Nachtsheim, P Wohlsein, Sara Persson, Rune Dietz, Ursula SiebertAbstract:Abstract The liver plays an important role in the metabolism and elimination of endogenic and exogenic lipid-soluble compounds. Multiple studies have shown that polychlorinated biphenyls (PCB) and dichlorodiphenyl trichloroethane (DDT) lead to morphological changes in liver cells. The aim of the present study was therefore to analyse liver changes over time in Baltic grey seals (Halichoerus Grypus) and to correlate these with historical PCB and DDT contaminations. A total of 191 liver samples were collected between 1981 and 2015 in the Gulf of Bothnia and northern Baltic Proper. Six histological features were evaluated, including portal mononuclear cell infiltration, random mononuclear cell infiltration, lipid granulomas, hepatocellular fat vacuoles, hepatic stellate cells and mild multifocal bile duct hyperplasia accompanied by portal fibrosis. Three of the six lesions showed a significant correlation with age. Furthermore, a positive correlation between portal mononuclear cell infiltration and mild multifocal bile duct hyperplasia was found. Additionally, lipid granulomas were significantly correlated with hepatic stellate cells. More importantly, hepatic stellate cells and mild multifocal bile duct hyperplasia were correlated with adipose tissue (blubber) concentrations of ƩPCB, measured in a subsample (n = 34) of all individuals. No correlation with lesions and ƩDDT concentrations were found. These results show that age is an important factor for the development of these liver lesions, but PCBs burden may be an influencing factor. This is in agreement with previous studies of marine mammals in the Baltic Sea as well as in the Arctic. We therefore conclude that not only age of the animals, but also exposure to PCBs should be taken into account when understanding and evaluating the current health status of Baltic grey seals.
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grey seal Halichoerus Grypus predation on harbour seals phoca vitulina on the island of helgoland germany
Journal of Sea Research, 2015Co-Authors: Abbo Van Neer, Lasse Fast Jensen, Ursula SiebertAbstract:Abstract The prey spectrum of grey seals has to date been described as largely consisting of different fish, cephalopod and shrimp species. On the German island of Helgoland Dune, where harbour seals ( Phoca vitulina ) and grey seals ( Halichoerus Grypus ) co-occur, a young male grey seal was observed in 2013 and again in 2014 preying upon young harbour seals. A harbour seal carcass with severe traumatic lesions was retrieved and post-mortem examinations were performed. In the following weeks several carcasses showing similar lesions were found. Sightings of grey seals assumed to be preying on harbour porpoises have increased around the North Sea. Increased competition as well as individualised behaviour could explain the increased number of observations, but former cases of abnormal lesions of marine mammals attributed to for example predation by sharks or mechanical processes should be revisited with regard to the emerging knowledge.
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in air evoked potential audiometry of grey seals Halichoerus Grypus from the north and baltic seas
PLOS ONE, 2014Co-Authors: Andreas Ruser, Iwona Pawliczka, Michael Dahne, Janne Sundermeyer, Klaus Lucke, Dorian S Houser, James J Finneran, Jorg Driver, Tanja Rosenberger, Ursula SiebertAbstract:In-air anthropogenic sound has the potential to affect grey seal (Halichoerus Grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1–20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4–20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal.
