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Published on: March 10, 2016
Energy in avian eggs and hatchlings: utilization and transfer
The Journal of Experimental Zoology. Supplement : Published Under Auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry
|January 1, 1987
Summary
Bird egg and hatchling energy content varies by maturity type, with precocial hatchlings having higher energy density. Overall energy transformation efficiency is consistent across maturity types, with metabolic losses being the primary inefficiency.
Area of Science:
- Avian biology
- Comparative physiology
- Energetics
Background:
- Understanding energy allocation in avian reproduction is crucial for evolutionary and ecological studies.
- Hatchling maturity types influence developmental strategies and energy demands.
Purpose of the Study:
- To analyze energy content and metabolic costs in bird eggs and hatchlings across different maturity types.
- To determine energy transformation efficiencies during embryonic development and hatching.
Main Methods:
- Analysis of energy content in eggs, hatchlings, and egg components (albumen, yolk, spare yolk) across 50 bird species.
- Categorization of species into four maturity types (e.g., precocial).
- Calculation of mass-specific energy densities and production efficiencies.
Main Results:
- Mass-specific energy density varied among maturity groups but was mass-independent within groups (fresh mass basis).
- Dry mass energy densities differed for hatchlings, with precocial hatchlings being more energy-dense.
- Gross production efficiency (63.7%) and total production efficiency (57.0%) were consistent across maturity types.
- Metabolic fuel loss accounted for 34.7% of energy used, with extraembryonic tissue and meconium losses at 8.3%.
Conclusions:
- Energy densities and transformation efficiencies are largely independent of maturity type.
- Differences among maturity types are primarily due to water content and energy density of dry matter in hatchlings.
- Energy transfer to spare yolk also contributes to inter-type differences.
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