GEOGRAPHIC VARIATION IN AVIAN INCUBATION PERIODS AND PARENTAL INFLUENCES ON EMBRYONIC TEMPERATURE

Geographic variation in avian incubation periods and parental influences on embryonic temperature.

Theory predicts shorter embryonic periods in species with greater embryo mortality risk and smaller body size. Field studies of 80 passerine species on three continents yielded data that largely conflicted with theory; incubation (embryonic) periods were longer rather than shorter in smaller species, and egg (embryo) mortality risk explained some variation within regions, but did not explain la...

Critical Periods and Causes of Death in Avian Embryonic Development

ARIAN embryonic mortality has long been a subject of biological interest. It is also a problem oœ obvious economic importance. The total embryonic mortality of domestic fowl, Gallus gallus, has been progressively increasing for some time. Less than 30 years ago, when flocks were small and kept at large, the embryonic death rate rarely exceeded i0 per cent. As simple and primitive methods of pou...

Effect of Pre-Incubation Storage Periods on Weight Loss, Embryonic Development, and Hatchability of Pullet Eggs

This study was carried out to determine the effect of pre-incubation storage periods on egg weight loss, embryonic development and hatchability of hatching pullet eggs. Three hundred eggs were used for this experiment. The eggs were sourced on five different days (sixty eggs per day) at three days interval (day 0, 3, 6, 9, and 12) and weighed. The sixty (60) eggs collected on each day were subd...

Ecological, evolutionary, and conservation implications of incubation temperature-dependent phenotypes in birds.

Incubation is a vital component of reproduction and parental care in birds. Maintaining temperatures within a narrow range is necessary for embryonic development and hatching of young, and exposure to both high and low temperatures can be lethal to embryos. Although it is widely recognized that temperature is important for hatching success, little is known about how variation in incubation temp...

Variation in the onset of incubation and its influence on avian hatching success and asynchrony