Crowned eagle eggs, like those of other bird species, can be left unattended for a certain period of time without negatively affecting their viability. However, the exact duration depends on various factors, including environmental conditions, the size of the clutch, and the foraging patterns of the parents.
The Ideal Incubation Period for Crowned Eagle Eggs
According to the Pennsylvania Game Commission, the average incubation period for a crowned eagle egg is 34 to 36 days. This means that, under normal circumstances, the parents should not leave the eggs unattended for more than a day or two.
Factors Affecting the Duration of Unattended Eggs
The resilience of the embryos and the ability of the parents to regulate the temperature of the eggs are crucial factors that determine how long a crowned eagle egg can be left unattended.
Temperature Regulation
Both male and female crowned eagles have a brood patch equipped with temperature sensors and specialized blood vessels that allow them to regulate the temperature of their eggs. Overheating is generally a more significant concern than overcooling, as eggs that reach temperatures above 40°C (104°F) rarely hatch.
Hatching Asynchrony
Hatching asynchrony is fairly common in the bird world, and the survival of the second chick might be a different story. In the case of crowned eagles, which exhibit obligate siblicide, the youngest chick invariably dies due to getting biffed by the older, bigger chick or due to starvation as the older chick nabs the majority of the food.
The Hanover Eagles Case
In the case of the Hanover eagles, the concern was that the eggs had been left unattended for more than an hour on a Friday afternoon. This was troubling to biologists, as it suggested that something might be amiss with the parents or the eggs. However, it is important to note that this was just a single instance, and it is unclear whether the eggs were left unattended for longer periods at other times.
Conclusion
While crowned eagle eggs can be left unattended for a certain period of time without negatively affecting their viability, prolonged periods of abandonment could potentially harm the developing embryos. The exact duration depends on various factors, including environmental conditions, the size of the clutch, and the foraging patterns of the parents. Under normal circumstances, the parents should not leave the eggs unattended for more than a day or two.
