Effects of down collection on incubation temperature, nesting behaviour and hatching success of common eiders (Somateria mollissima) in west Iceland

Abstract Here we present the recording of body mass change and weight loss during incubation in a Common Eider Somateria mollissima colony at Christiansø in the Central Baltic (55°19’N 15°11’E). The study was conducted during April and May 2015 and a total number of four birds were followed (two were lost due to predation and three due to power outages). Body mass and nesting behaviour was recorded electronically over a period of 26–27 days using automatic poultry scales and a surveillance video camera. During incubation, the eiders underwent a 28–37% loss in body mass and left the nest on average 13 times (range: 7–17 times) for a period of 7–70 min. In general, birds with high initial body mass left their nest for a shorter total time than birds with lower initial body mass. The recorded daily changes in body mass indicate that the eiders foraged during the incubation period, not just leaving the nest for rehydration or in response to disturbance, which improve our current understanding of eider incubation behaviour. Such information is important to fully understanding of eider breeding biology in order to better conserve and manage the species during its breeding seasons where individual birds undergo extreme stress that may affect reproductive outcome and adult survival.

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Intraclutch egg-size variation and hatching success in the common eider

Canadian Journal of Zoology ◽

10.1139/z93-075 ◽

1993 ◽

Vol 71 (3) ◽

pp. 544-549 ◽

Cited By ~ 34

Author(s):

Gregory J. Robertson ◽

Fred Cooke

Keyword(s):

Egg Size ◽

Hatching Success ◽

Size Variation ◽

Hudson Bay ◽

Somateria Mollissima ◽

Physiological Mechanisms ◽

Common Eiders ◽

Laying Sequence ◽

The Common ◽

Nutrient Reserves

Intraclutch egg-size variation and hatching success were studied in a population of Hudson Bay common eiders (Somateria mollissima sedentaria) at La Pérouse Bay, Manitoba (58°24′N, 94°24′W), to test the hypothesis that females allocate more nutrient reserves to eggs that are more likely to hatch. Egg volumes were calculated for 575 known-sequence eggs in 134 complete clutches of 3–6 eggs. In general, the length of eggs decreased linearly with position in the laying sequence, whereas the breadth of eggs followed a curvilinear pattern, the second or third egg being the widest. For all clutch sizes, the last-laid egg was the smallest and the second- or third-laid egg the largest. Hatching success also varied with position in the laying sequence. Pre-incubation failure declined over the laying sequence, whereas hatching failure (dead, infertile, or rotten eggs) increased. In all cases pre-incubation failure was the major cause of egg loss (84% of total loss). Overall, third and fourth eggs were the most successful and first eggs were the least successful. With one exception, successful and unsuccessful eggs were the same size within a laying sequence. We conclude that there is no clear relationship between egg size and hatching success, and that laying sequence per se has a greater effect on hatching success. Female eiders do not appear to allocate more reserves to eggs that are most likely to hatch, and we consider other proximate, physiological mechanisms to explain the observed pattern of intraclutch egg-size variation.

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Nest cover and faecal glucocorticoid metabolites are linked to hatching success and telomere length in breeding Common Eiders (Somateria mollissima)

Canadian Journal of Zoology ◽

10.1139/cjz-2016-0242 ◽

2017 ◽

Vol 95 (9) ◽

pp. 695-703 ◽

Cited By ~ 3

Author(s):

K. Noreikiene ◽

M. Öst ◽

M.W. Seltmann ◽

W. Boner ◽

P. Monaghan ◽

...

Keyword(s):

Telomere Length ◽

Hatching Success ◽

Prolonged Exposure ◽

Somateria Mollissima ◽

Faecal Glucocorticoid Metabolites ◽

Common Eiders ◽

Nesting Sites ◽

Escape Responses ◽

The Relationship ◽

Perceived Predation Risk

Habitat-associated crypsis may affect perceived predation vulnerability, selecting for different predator avoidance strategies. Glucocorticoids could mediate the adjustment of escape responses to the extent of crypsis, introducing an overlooked source of variation in glucocorticoid–fitness relationships. However, prolonged exposure to elevated glucocorticoids may be costly, leading to accelerated telomere loss and, consequently, senescence. Here, we examined how nest cover and immunoreactive faecal glucocorticoid metabolite (fGCM) levels are linked to hatching success and telomere length in breeding female Common Eiders (Somateria mollissima (L., 1758)). We hypothesized that the degree of nest crypsis, reflecting differences in perceived predation risk, would moderate the relationship between reproductive success and fGCM levels. We also expected that telomere length would be shorter in birds with higher glucocorticoid concentration. Results showed that individuals with high fGCM levels had higher hatching success in nests with low cover, while low fGCM levels were more successful in well-concealed nests. We found that shorter telomeres were associated with high fGCM in nesting sites offering little cover and with low fGCM in well-concealed ones. This study provides the first evidence of habitat-dependent moderation of the relationships between stress physiology, telomere length and hatching success.

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Parental Investment Under Predation Threat in Incubating Common Eiders (Somateria mollissima): A Hormonal Perspective

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.637561 ◽

2021 ◽

Vol 9 ◽

Author(s):

Bertille Mohring ◽

Frédéric Angelier ◽

Kim Jaatinen ◽

Charline Parenteau ◽

Markus Öst

Keyword(s):

Predation Risk ◽

Body Condition ◽

Parental Investment ◽

Nest Predation ◽

Hatching Success ◽

Reproductive Investment ◽

Somateria Mollissima ◽

Common Eiders ◽

Adaptation Hypothesis ◽

The Impact

Predation risk affects the costs and benefits of prey life-history decisions. Predation threat is often higher during reproduction, especially in conspicuous colonial breeders. Therefore, predation risk may increase the survival cost of breeding, and reduce parental investment. The impact of predation risk on avian parental investment decisions may be hormonally mediated by prolactin and corticosterone, making them ideal tools for studying the trade-offs involved. Prolactin is thought to promote parental care and commitment in birds. Corticosterone is involved in allostasis and may either mediate reduced parental investment (corticosterone-fitness hypothesis), or promote parental investment through a reallocation of resources (corticosterone-adaptation hypothesis). Here, we used these hormonal proxies of incubation commitment to examine the impact of predation risk on reproduction in common eiders (Somateria mollissima) breeding in the Baltic Sea. This eider population is subject to high but spatially and temporally variable predation pressure on adults (mainly by the white-tailed eagle Haliaeetus albicilla and introduced mammalian predators) and nests (by the adult predators and exclusive egg predators such as hooded crows Corvus cornix). We investigated baseline hormonal levels and hatching success as a function of individual quality attributes (breeding experience, female and duckling body condition), reproductive investment (clutch weight), and predation risk. We expected individuals nesting in riskier environments (i.e., on islands where predation on adults or nests is higher, or in less concealed nests) to reduce their parental investment in incubation, reflected in lower baseline prolactin levels and either higher (corticosterone-fitness hypothesis) or lower (corticosterone-adaptation hypothesis) baseline corticosterone levels. Contrary to our predictions, prolactin levels showed a positive correlation with nest predation risk. The unexpected positive relationship could result from the selective disappearance of low-quality females (presumably having low prolactin levels) from risky sites. Supporting this notion, female body condition and hatching success were positively correlated with predation risk on females, and baseline prolactin concentrations were positively correlated with duckling body condition, a proxy of maternal quality. In line with the corticosterone-adaptation hypothesis, baseline corticosterone levels increased with reproductive investment, and were negatively associated with nest predation risk. Hatching success was lower on islands where nest predation risk was higher, consistent with the idea of reduced reproductive investment under increased threat. Long-term individual-based studies are now needed to distinguish selection processes occurring at the population scale from individually plastic parental investment in relation to individual quality and variable predation risk.

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

Scientific Reports ◽

10.1038/s41598-020-79888-6 ◽

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.

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

Canadian Journal of Zoology ◽

10.1139/cjz-2015-0062 ◽

2015 ◽

Vol 93 (10) ◽

pp. 755-764 ◽

Cited By ~ 3

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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Effects of constant incubation regimes on eggs and hatchlings of the egg-laying skink, Oligosoma suteri

10.26686/wgtn.17059868 ◽

2021 ◽

Author(s):

◽

Kelly Maree Hare

Keyword(s):

Hatching Success ◽

Incubation Temperature ◽

Unit Length ◽

Condition Index ◽

Egg Laying ◽

Maternal Influence ◽

Temperature Dependent ◽

Sprint Speed ◽

Fitness Traits ◽

Incubation Temperatures

<p>The conditions under which reptilian eggs are incubated affect survival probability and physiological attributes of the progeny. The egg-laying skink, Oligosoma suteri, is the only endemic oviparous lizard in New Zealand. No controlled laboratory incubation had previously been undertaken, and thus no information was available on the requirements for successful captive incubation. I studied the effects of incubation regime on the eggs and hatchlings of O. suteri to four months of age. Oligosoma suteri eggs (n = 174) were randomly distributed among three constant incubation temperatures (18°C, 22°C and 26°C) and two water potentials (-120 kPa and -270 kPa). Hatching success and hatchling survival were greatest at 22°C and 26°C, with hatchlings from 18°C incubation suffering from physical abnormalities. Incubation regime and maternal influence did not affect sex of individuals, with equal sex ratios occurring from each incubation treatment. Hatchlings from the 22°C and -120 kPa incubation treatments were larger, for most measurements, and warmer incubation temperatures resulted in increased growth rates. Juveniles from 22°C and 26°C and individuals with greater mass per unit length (condition index) sprinted faster over 0.25 m. Sprint speed was positively correlated with ambient temperature. At four months of age sprint speed decreased in 18°C individuals and individuals incubated at 26°C and -270 kPa compared to their performance at one month. The results suggest that the most successful captive incubation regime for O. suteri is 22°C and -120 kPa. This study also shows that temperature-dependent sex determination does not occur in O. suteri, but that fitness traits are influenced by incubation temperature.</p>

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Seroprevalence of avian influenza in Baltic common eiders (Somateria mollissima) and pink-footed geese (Anser brachyrhynchus)

Environment International ◽

10.1016/j.envint.2020.105873 ◽

2020 ◽

Vol 142 ◽

pp. 105873 ◽

Cited By ~ 1

Author(s):

Su Shiung Lam ◽

Rune Skjold Tjørnløv ◽

Ole Roland Therkildsen ◽

Thomas Kjær Christensen ◽

Jesper Madsen ◽

...

Keyword(s):

Avian Influenza ◽

Somateria Mollissima ◽

Anser Brachyrhynchus ◽

Common Eiders

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

Avian Biology Research ◽

10.3184/175815618x15263798903780 ◽

2018 ◽

Vol 11 (3) ◽

pp. 167-172 ◽

Cited By ~ 14

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.

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