Oxyura jamaicensis: BirdLife International

Abstract In birds, large egg size often enhances subsequent offspring survival, but most previous studies have been unable to separate effects of egg size from other maternal influences. Therefore, we first evaluated variance components of egg size both within and among individual female Ruddy Ducks (Oxyura jamaicensis), and then tested for egg-size-dependent survival of ducklings in the wild by switching complete broods among females. Forty broods consisting of 244 individually color-marked, day-old ducklings of known egg size were given to foster mothers, and survival was monitored to one month. Analysis of mark–resighting data showed that offspring survival was best modeled to include effects of egg size and hatching date; survival probability increased with egg size, but declined with advancing hatching date. Duckling body mass, body size, and body condition measured at hatching were positively correlated with egg size. Unlike most other duck species, and for reasons that are speculative, egg sizes varied within clutches nearly as much as they did among clutches. Selective mortality of small egg phenotypes during the first weeks after hatching likely is the result of smaller duckling size and reduced energy reserves, characteristics that must be particularly unfavorable in adverse environments.

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Consequences of Egg Size for Offspring Survival: A Cross-Fostering Experiment in Ruddy Ducks (Oxyura jamaicensis)

The Auk ◽

10.2307/4090190 ◽

2003 ◽

Vol 120 (2) ◽

pp. 384-393 ◽

Cited By ~ 2

Author(s):

Jeffrey T. Pelayo ◽

Robert G. Clark

Keyword(s):

Egg Size ◽

Offspring Survival ◽

Ruddy Ducks ◽

Cross Fostering ◽

Oxyura Jamaicensis

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Segregation in feeding behaviour of four diving ducks in southern Manitoba

Canadian Journal of Zoology ◽

10.1139/z76-084 ◽

1976 ◽

Vol 54 (5) ◽

pp. 730-736 ◽

Cited By ~ 10

Author(s):

W. R. Siegfried

Keyword(s):

Feeding Behaviour ◽

Canadian Prairie ◽

Diving Ducks ◽

Small Wetlands ◽

Selection For ◽

Ruddy Duck ◽

Oxyura Jamaicensis

The canvasback, Aythya valisinaria; redhead, A. americana; scaup, A. affinis; and ruddy duck, Oxyura jamaicensis, are sympatric on the small wetlands of the Canadian prairie region. The four species did not occur randomly and each species tended to occur by itself more often than with any other species. Each species tended to forage in a particular part of a pond. Selection for different foraging sites appears to be important in segregating those species whose diets overlap most.

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Variation in Size, Composition, and Quality of Ruddy Duck Eggs and Ducklings

The Condor ◽

10.1093/condor/104.2.457 ◽

2002 ◽

Vol 104 (2) ◽

pp. 457-462 ◽

Cited By ~ 2

Author(s):

Jeffrey T. Pelayo ◽

Robert G. Clark

Keyword(s):

Body Size ◽

Egg Size ◽

Size Composition ◽

Egg Mass ◽

Direct Proportion ◽

Female Body Size ◽

Ruddy Duck ◽

Better Than ◽

Oxyura Jamaicensis

AbstractTo evaluate why ducklings hatching from large eggs generally survive better than ducklings from small eggs, we quantified egg-size-related variation in composition and quality of eggs and ducklings of wild Ruddy Ducks (Oxyura jamaicensis). Fresh egg mass averaged 74.1 ± 4.3 g (SD), but ranged from 60.5 to 83.8 g. Despite remarkably large egg size relative to adult female body size, and a 1.4-fold difference in mass between the smallest and largest eggs, most egg constituents increased in direct proportion to fresh egg mass, with bigger eggs producing heavier and larger ducklings. However, large ducklings had proportionately larger yolk sac stores than did small ducklings. Thus, large ducklings also had greater total lipid reserves, an advantage that could enable them to survive better than small ducklings during the first few days after hatching.Variación en el Tamaño, Composición y Calidad de los Huevos y Polluelos de Oxyura jamaicensisResumen. Para evaluar por qué los polluelos que eclosionan de huevos grandes sobreviven mejor que polluelos provenientes de huevos pequeños, cuantificamos la variación en la composición y calidad de huevos y polluelos en relación al tamaño del huevo en Oxyura jamaicensis. La masa fresca de los huevos promedió 74.1 ± 4.3 g (DE), pero varió entre 60.5 y 83.8 g. A pesar del gran tamaño de los huevos en relación al tamaño corporal de la hembra, y de una diferencia de 1.4 veces en la masa entre el huevo más pequeño y él más grande, la mayoría de los componentes del huevo aumentaron en proporción directa con la masa fresca del huevo. Huevos más grandes produjeron polluelos más grandes y pesados. Sin embargo, polluelos grandes presentaron relativamente mayores reservas en el saco vitelino que polluelos pequeños. Por lo tanto, los polluelos grandes también presentaron una mayor reserva total de lípidos, ventaja que podría permitirles sobrevivir mejor que a los polluelos más pequeños durante los primeros días luego de la eclosión.

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