Fledgling production and population trends in Finnish common eiders (Somateria mollissima mollissima) — evidence for density dependence

2006 ◽  
Vol 84 (7) ◽  
pp. 1038-1046 ◽  
Author(s):  
Martti Hario ◽  
Jukka Rintala
Keyword(s):  
Density Dependence ◽  
Viral Infections ◽  
Population Decline ◽  
Negative Relationship ◽  
Somateria Mollissima ◽  
Breeding Parameters ◽  
Brood Rearing ◽  
Common Eiders ◽  
Water Rate ◽  
The Baltic

We present a 57-year time series of a common eider, Somateria mollissima mollissima (L., 1758), population from one of the core monitoring areas in the Baltic Sea, the Söderskär bird sanctuary, Gulf of Finland. We applied permutation tests to inspect the relationships between breeding parameters and population density. Of the parameters studied, only fledging rate (during a 34-year period) showed a significant negative relationship with population size, indicating density dependence. Furthermore, the fledging rate responded strongly to the population growth rate and to the rate of recruitment. Clutch size and duckling (downy young entering the water) rate did not show negative density dependence. Thus, losses during brood rearing seem to be the regulatory factor. The population decline at Söderskär is similar to those recorded in many other monitoring sites around the southern coast of Finland. Compared with data from more productive sea districts in northwestern Europe (Dutch Wadden Sea and Scottish North Sea), the Finnish fledging rates do not seem excessively bad. There are indications of viral infections playing an increasingly central role in duckling mortality, whereas adult female mortality has not been affected.

Common Eider (Somateria Mollissima) Body Condition and Parasitic Load during a Mortality Event in the Baltic Proper

2018 ◽  
Vol 11 (3) ◽  
pp. 167-172 ◽  
Author(s):  
Svend-Erik Garbus ◽  
Peter Lyngs ◽  
Jens Peter Christensen ◽  
Kurt Buchmann ◽  
Igor Eulaers ◽  
...  
Keyword(s):  
Body Mass ◽  
High Mortality ◽  
Physiological Stress ◽  
Morphological Changes ◽  
Somateria Mollissima ◽  
Common Eiders ◽  
Baltic Proper ◽  
Average Body Mass ◽  
The Baltic ◽  
Average Body

During late spring of 2007 and 2015, we observed unusually high mortality of Common Eiders (Somateria mollissima) on Christiansø in the Baltic Proper. The number of dead birds (2007: 125; 2015: 110) composed 5–10% of the total colony. In 2015, we collected 15 (12 adult females, three subadult males) of the 110 recently deceased Common Eiders for detailed autopsy. The average body mass of the females was 1,040 g (920–1,160 g) which is ca 60% lower than what can be expected of healthy females during wintertime. Similarly, for the subadult males the average body mass of 1,203 g (1,070–1,300 g) comprised only 45% of what can be expected for healthy subadult males during winter. All 15 birds were thus severely emaciated and cachexic with general atrophy of muscles and internal organs. Hunger oedema, distended gall bladder, empty stomach, empty and dilated intestines and dilated cardiomyopathy were observed as well. In addition, all 15 Common Eiders were infected with high loads of the acanthocephalan parasite Polymorphus minutus. No gross morphological changes suggested toxicological, bacteriological or viral causes to the mortality. Taken together, our autopsy suggested starvation leading to secondary metabolic catabolism and eventually congestive heart failure. Five birds that were examined in 2007 showed the same symptoms. We suspect that the introduction of suboptimal feeding conditions in combination with a high parasite load over the last decade synergistically caused high physiological stress leading to population level effects manifested as high mortality.

scholarly journals AN ADENOVIRUS ASSOCIATED WITH INTESTINAL IMPACTION AND MORTALITY OF MALE COMMON EIDERS (SOMATERIA MOLLISSIMA) IN THE BALTIC SEA

2003 ◽  
Vol 39 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Tuula E. Hollmén ◽  
J. Christian Franson ◽  
Mikael Kilpi ◽  
Douglas E. Docherty ◽  
Vesa Myllys
Keyword(s):  
Baltic Sea ◽  
Somateria Mollissima ◽  
The Baltic Sea ◽  
Common Eiders ◽  
The Baltic

Population decline in semi-migratory caribou (Rangifer tarandus): intrinsic or extrinsic drivers?

2013 ◽  
Vol 91 (11) ◽  
pp. 820-828 ◽  
Author(s):  
Guillaume Bastille-Rousseau ◽  
James A. Schaefer ◽  
Shane P. Mahoney ◽  
Dennis L. Murray
Keyword(s):  
Density Dependence ◽  
Rangifer Tarandus ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Population Decline ◽  
Negative Relationship ◽  
Population Limitation ◽  
Continental Scale ◽  
Delayed Density Dependence ◽  
Winter Severity

Many populations of caribou (Rangifer tarandus (L., 1758)) across North America, including Newfoundland, are in a state of decline. This phenomenon may reflect continental-scale changes in either the extrinsic or the intrinsic factors affecting caribou abundance. We hypothesized that caribou decline reflected marked resource limitation and predicted that fluctuations should correspond to time-delayed density dependence associated with a decline in range quality and decadal trends in winter severity. By conducting time-series analysis using 12 populations and evaluating correlations between caribou abundance and trends in (i) vegetation available at calving (normalized difference vegetation index, NDVI), (ii) winter weather severity (index of North Atlantic Oscillation, NAO), and (iii) caribou morphometrics, we observed strong evidence of density dependence in population dynamics (i.e., a negative relationship between caribou population size and caribou morphometrics). Caribou population trajectories were time-delayed relative to winter severity, but not relative to calving-ground greenness. These island-wide correlations could not be traced to dispersal between herds, which appears rare at least for adult females. Our results suggest that trends in winter severity may synchronize broad-scale changes in caribou abundance that are driven by time-delayed density dependence, although it remains possible that calving-ground deterioration also may contribute to population limitation in Newfoundland. Our findings provide the basis for additional research into density dependence and caribou population decline.

scholarly journals Effects of Data-Loggers Implanted for a Full Year in Female Common Eiders

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 448-452 ◽  
Author(s):  
Magella Guillemette ◽  
Anthony J. Woakes ◽  
Annette Flagstad ◽  
Patrick J. Butler
Keyword(s):  
Harmful Effect ◽  
Body Cavity ◽  
The Body ◽  
Control Group ◽  
Somateria Mollissima ◽  
Aerodynamic Properties ◽  
Data Loggers ◽  
Common Eiders ◽  
The Baltic ◽  
The Impact

Abstract Data-loggers can be implanted into the body cavities of birds to monitor their physiology and behavior. This technology opens the potential for year-round monitoring, as long as data-loggers can be retrieved one year later and the implantation does not alter the bird's health or behavior. We tested the impact of carrying data-loggers on reproductive parameters of nine female Common Eiders breeding in the Baltic Sea. We minimized disturbance and maximized return rates of experimental females by implanting data-loggers during the second half of the incubation period and by choosing early breeders, which were presumably high quality individuals. All experimental females came back to the study plot the year following implantation. Using a before-after approach applied to an experimental and a control group, we found no evidence that carrying data-loggers had any harmful effect on laying dates, clutch sizes, or hatching success of experimental females. It appears that data-loggers implanted in the body cavities of female Common Eiders do not interfere with their reproductive activities. Explanations for this result are that data-loggers are small compared to body mass (<1%), and their implantation into the body cavity does not alter the hydrodynamic or aerodynamic properties of these diving birds. Efectos de Medidores Implantados por un Año Completo en Hembras de Somateria mollissima Resumen. Pequeños medidores (i.e., “data-loggers”) pueden ser implantados en las cavidades corporales de las aves para monitorear su fisiología y comportamiento. Esta tecnología abre el potencial para realizar monitoreos a lo largo del año, siempre y cuando los medidores puedan ser recuperados un año más tarde y éstos no afecten la salud o el comportamiento de las aves. Evaluamos el impacto de llevar medidores sobre parámetros reproductivos de nueve hembras de la especie Somateria mollissima que se estaban reproduciendo en el Mar Báltico. Minimizamos el disturbio y maximizamos las tasas de retorno de las hembras experimentales implantando los medidores durante la segunda mitad del período de incubación y escogiendo aquellas que se reprodujeron al comienzo de la estación, que presumiblemente eran individuos de alta calidad. Todas las hembras experimentales regresaron al sitio de estudio al año siguiente de la implantación. Utilizando un método de antes y después aplicado a un grupo experimental y a uno de control, no encontramos evidencia de que llevar medidores tenga algún efecto negativo sobre la fecha de postura, el tamaño de la nidada o el éxito de eclosión de las hembras experimentales. Al parecer, los medidores implantados en las cavidades corporales de las hembras de S. mollissima no interfieren con sus actividades reproductivas. Las explicaciones para este resultado son que los medidores son pequeños en comparación con la masa corporal (<1%), y que su implantación en la cavidad corporal no altera las propiedades hidrodinámicas ni aerodinámicas de estas aves buceadoras.

Evidence of chromosomal damage in common eiders (Somateria mollissima) from the Baltic Sea

2004 ◽  
Vol 49 (11-12) ◽  
pp. 1066-1071 ◽  
Author(s):  
Cole W. Matson ◽  
J. Christian Franson ◽  
Tuula Hollmén ◽  
Mikael Kilpi ◽  
Martti Hario ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Somateria Mollissima ◽  
Chromosomal Damage ◽  
The Baltic Sea ◽  
Common Eiders ◽  
The Baltic

scholarly journals Lead concentrations in blood from incubating common eiders (Somateria mollissima) in the Baltic Sea

2020 ◽  
Vol 137 ◽  
pp. 105582 ◽  
Author(s):  
Su Shiung Lam ◽  
Molly McPartland ◽  
Brenley Noori ◽  
Svend-Erik Garbus ◽  
Syverin Lierhagen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Somateria Mollissima ◽  
The Baltic Sea ◽  
Common Eiders ◽  
The Baltic

scholarly journals Herd immunity drives the epidemic fadeout of avian cholera in Arctic-nesting seabirds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jacintha G. B. van Dijk ◽  
Samuel A. Iverson ◽  
H. Grant Gilchrist ◽  
N. Jane Harms ◽  
Holly L. Hennin ◽  
...  
Keyword(s):  
Colony Size ◽  
Pasteurella Multocida ◽  
Herd Immunity ◽  
Reproductive Number ◽  
Somateria Mollissima ◽  
Common Eiders ◽  
Serological Status ◽  
Antibody Titers ◽  
Avian Cholera

AbstractAvian cholera, caused by the bacterium Pasteurella multocida, is a common and important infectious disease of wild birds in North America. Between 2005 and 2012, avian cholera caused annual mortality of widely varying magnitudes in Northern common eiders (Somateria mollissima borealis) breeding at the largest colony in the Canadian Arctic, Mitivik Island, Nunavut. Although herd immunity, in which a large proportion of the population acquires immunity to the disease, has been suggested to play a role in epidemic fadeout, immunological studies exploring this hypothesis have been missing. We investigated the role of three potential drivers of fadeout of avian cholera in eiders, including immunity, prevalence of infection, and colony size. Each potential driver was examined in relation to the annual real-time reproductive number (Rt) of P. multocida, previously calculated for eiders at Mitivik Island. Each year, colony size was estimated and eiders were closely monitored, and evaluated for infection and serological status. We demonstrate that acquired immunity approximated using antibody titers to P. multocida in both sexes was likely a key driver for the epidemic fadeout. This study exemplifies the importance of herd immunity in influencing the dynamics and fadeout of epidemics in a wildlife population.

Body and organ mass dynamics during remigial moult in a wing–foot-propelled diving sea duck: the Common Eider (Atlantic) (Somateria mollissima dresseri)

2015 ◽  
Vol 93 (10) ◽  
pp. 755-764 ◽  
Author(s):  
A. Viain ◽  
M. Guillemette ◽  
J.-P.L. Savard
Keyword(s):  
Muscle Mass ◽  
Body Mass ◽  
Flight Muscle ◽  
Somateria Mollissima ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Common Eiders ◽  
Sea Duck ◽  
Remigial Moult ◽  
Atrophy Of The Heart

Body and organ dynamics, during remigial moult, have been mainly explored on geese, dabbling ducks, and foot-propelled diving ducks, but weakly on sea ducks. This study investigated the internal changes in a wing–foot-propelled sea duck to determine the adaptive strategies implemented. Forty-five male Common Eiders (Atlantic) (Somateria mollissima dresseri Sharpe, 1871), collected in the Gulf of St. Lawrence, were dissected; their body mass, muscle mass, and organ sizes were measured. We tested three hypotheses: (1) S. m. dresseri use a strategic reduction of body mass to reduce the flightlessness duration; (2) organs will exhibit changes consistent with a trade-off between function and maintenance to save and reallocate energy and proteins to feather growth; (3) S. m. dresseri would show lower flight muscle reduction than foot-propelled diving ducks. Somateria mollissima dresseri did not lose body mass, which does not support the first hypothesis. Atrophy of the heart followed by hypertrophy and opposite changes in leg muscle mass and gizzard mass are consistent with the second hypothesis. Flight muscle mass showed lower variations than in other ducks, validating the third hypothesis. We also suggest that the lipid depletion observed early in the moult could be a strategy to reduce foraging effort and minimize the risk of damaging the growing feathers.

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