Subtle Egg‐Shell Membrane Structures in Birds’ Eggs

Intraclutch eggshell colour variation in birds: are females able to identify their eggs individually?

BACKGROUND One possibility suggested regarding female post-mating strategies is differential allocation into offspring investment. Female birds produce not only the largest, but also most colourful eggs of all oviparous taxa. Larger eggs provide space for bigger embryos, or more nutrition for their development, but the question why eggs are more colourful and why there is variation in eggshell ...

The Shapes of Birds' Eggs

Why are birds’ eggs colourful? Eggshell pigments co-vary with life-history and nesting ecology among British breeding non-passerine birds

School of Earth and Environmental Sciences, University of Adelaide, SA 5005, Australia School of Biosciences, University of Birmingham, Edgbaston B15 2TT, UK School of Biological Sciences, Bristol University, Bristol BS8 1TH, UK Royal Veterinary College, Hawkshead Lane, Hertfordshire AL9 7TA, UK Department of Psychology, Hunter College and the Graduate Center of the City University of New York,...

The effect of eggshell thickness on hatchability of quail eggs

BACKGROUND AND AIM The aim of the successful incubation period is to achieve maximum health chicks in each batch. Therefore, all factors affecting incubation have to be investigated in detail. This study investigated the effect of eggshell thickness on hatchability of quail eggs. MATERIALS AND METHODS A total of 1415 eggs were collected from the same flock at the ages of 23 and 41 weeks. Two ...

Subtle manipulation of egg sex ratio in birds.

Mothers are predicted to overproduce male or female eggs when the relative fitness gains from one sex are higher and outweigh the costs of manipulation. However, in birds such biases are often difficult to distinguish from differential embryo or chick mortality. Using a molecular technique to identify the sex of early embryos, we aim to determine the effect of maternal nutrition on zebra finch ...