Effects of Cohort and Individual Variation in Duckling Body Condition on Survival and Recruitment in the Common Eider Somateria mollissima

1999 ◽  
Vol 30 (3) ◽  
pp. 302 ◽  
Author(s):  
Thomas Kjaer Christensen
Keyword(s):  
Body Condition ◽  
Individual Variation ◽  
Common Eider ◽  
Somateria Mollissima ◽  
The Common

scholarly journals Condition dependent strategies of egg size variation in the Common Eider Somateria mollissima

2019 ◽  
Author(s):  
Thomas Kjær Christensen ◽  
Thorsten Johannes Skovbjerg Balsby
Keyword(s):  
Clutch Size ◽  
Body Condition ◽  
Egg Size ◽  
Size Variation ◽  
Common Eider ◽  
Somateria Mollissima ◽  
Individual Level ◽  
Laying Sequence ◽  
The Common ◽  
Using Data

AbstractWe analysed intraclutch egg-size variation in relation to clutch size and to female body condition in the Common Eider Somateria mollissima during an 8-year period. The aim was to assess if eiders adaptively adjusted egg size within the laying sequence in response to different clutch sizes, which potentially could optimise reproductive success through a size advantage in hatchlings. The analyses were performed on both population and individual level using data from recaptured females that changed clutch size between seasons. Based on 1,099 clutches from 812 individual females, population clutch size averaged 4.13 eggs (range: 1-6), with marked annual variation in the dominance of 4- and 5-egg clutches, which constituted c.70% of all clutches. Clutch size was positively related to female pre-laying body condition at both the population and individual level. Egg size varied significantly within and between clutch sizes and changes were significantly related to the laying sequence. First eggs were significantly larger in 4-egg clutches and second eggs smaller (marginally insignificant) than in 5-egg clutches, a pattern also found among individual females changing clutch size between seasons. The relationship between female pre-laying body condition, clutch size and the intraclutch egg-size pattern indicates that both clutch size and egg size is actively adapted to the pre-breeding body condition of the female. We suggest that the observed pattern of intraclutch egg-size variation reflects a finely tuned conditional dependent mechanisms that enable females in a suboptimal condition to optimize reproductive output.

Female sociality in the common eider duck during brood rearing

1982 ◽  
Vol 60 (12) ◽  
pp. 3326-3331 ◽  
Author(s):  
J. K. Schmutz ◽  
R. J. Robertson ◽  
F. Cooke
Keyword(s):  
Maternal Care ◽  
Adaptive Significance ◽  
Common Eider ◽  
Somateria Mollissima ◽  
Brood Rearing ◽  
The Common ◽  
Nutrient Reserves ◽  
Prolactin Hormone

This study investigates the potential adaptive significance of the behavior of female common eider ducks (Somateria mollissima) which have no young of their own ("aunts") but accompany other females and young. "Aunts" exhibited ambivalent aggression and protection toward ducklings. There was no evidence that the presence of "aunts" enhanced the survival of the ducklings they accompanied. Both females which had their clutch removed and females which had not laid eggs behaved as "aunts." The level of circulating prolactin hormone in "aunts" was lower than in incubating females and similar to the basal level of males. We therefore rejected the hypothesis that maternal care was misdirected during hormonal adjustment from breeding to nonbreeding. We suggest that "aunts" which have lost a clutch or brood, spend some time feeding away from the colony, and then return to the nesting grounds after replenishing their nutrient reserves. Upon returning, "aunts" may select sites for nesting in future years. During this time, they are temporarily attracted to broods. We propose that "aunts" flock and fend off predators during an attack in an attempt to seek safety in a flock rather than to protect ducklings of other females.

Sex and age structures of the White Sea endemic population of the common eider Somateria mollissima

2010 ◽  
Vol 435 (1) ◽  
pp. 435-437 ◽  
Author(s):  
Yu. V. Krasnov ◽  
M. V. Gavrilo ◽  
A. A. Shavykin ◽  
P. S. Vashchenko
Keyword(s):  
White Sea ◽  
Common Eider ◽  
Somateria Mollissima ◽  
The White Sea ◽  
Endemic Population ◽  
The Common ◽  
Age Structures

scholarly journals Helminthes of the Common Eider (Somateria mollissima) on the Eastern Murman, its impact on the digestive activity and physiological state

2019 ◽  
Vol 487 (1) ◽  
pp. 107-110
Author(s):  
M. M. Kuklina ◽  
V. V. Kuklin
Keyword(s):  
Small Intestine ◽  
Species Composition ◽  
Intestinal Mucosa ◽  
Physiological State ◽  
Common Eider ◽  
Somateria Mollissima ◽  
Control Parameters ◽  
Hematological Indices ◽  
The Common ◽  
Digestive Activity

An ecological and physiological study of Common Eider (Somateria mollissima) nesting on the coast of Eastern Murman was carried out. The species composition of helminthofauna of birds and the quantitative parameters of the infection were studied. It is established that trematodes of the genus Microphallus, three species of cestodes - Lateriporus teres (Cestoda: Dilepididae), Fimbriarioides intermedia (Cestoda: Hymenolepididae), Microsomacanthus diorchis (Cestoda: Hymenolepididae) and one species of acanthocephalan - Polymorphus phippsi (Palaeacanthocephala: Polymorphidae) parasitized in the small intestine of Common Eider. It is shown that the activity of proteases decreased at the locations of F. intermedia and M. diorchis in the intestines of birds, with infestation with the acanthocephalan P. phippsi, on the contrary, increased. The activity of glycosides in the intestinal mucosa was reduced in comparison with the control values by infection cestodes M. diorchis. There was an increase in the values of hematological indices in infected individuals relative to the control parameters.

An ultrastructural study of reproduction in the parthenogenetic metacercariae of Cercaria margaritensis Ching, 1982 (Digenea: Gymnophallidae)

Parasitology ◽  
2003 ◽  
Vol 126 (3) ◽  
pp. 261-271 ◽  
Author(s):  
S. W. B. IRWIN ◽  
K. V. GALAKTIONOV ◽  
I. I. MALKOVA ◽  
D. H. SAVILLE ◽  
S. M. FITZPATRICK
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Embryo Development ◽  
Ultrastructural Study ◽  
Definitive Host ◽  
Parent Body ◽  
Common Eider ◽  
Somateria Mollissima ◽  
Transmission Electron ◽  
The Common

The parthenogenetic metacercarial stages of the gymnophallid trematode Cercaria margaritensis are found in the extrapallial cavity of the subtidal prosobranch mollusc Margarites helicinus. The primary metacercariae (M1) produce second-generation metacercariae (M2) which become independent and give rise to M3 metacercariae which are infective to the definitive host, the common eider (Somateria mollissima). This study used transmission electron microscopy to follow the development of M2 inside M1 organisms and M3 inside M2 organisms. The process is similar in both cases with embryos developing from individual cells from the parent body walls. In each case the brood sac was divided into brood chambers by multilaminated cells and both M2 and M3 embryos developed inside embryonic membranes that originated from specialized blastomeres. The tegument of M2 and M3 embryos developed in a similar manner underneath the embryonic membrane. Both the multilaminated cells and the embryonic membranes possessed features that indicated that they are involved in transport of nutrients. It is suggested that the continuous nature of M2 and M3 embryo development may well be similar to that postulated for ancestral digeneans.

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