ArticleIntegrative zoology2025
Pear-Shaped Eggs Evolved to Maximize the Surface Area-to-Volume Ratio, Increase Metabolism, and Shorten Incubation Time in Birds.
Article in Integrative zoology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
4 citing papers in PubMed.
- Breeding Biology of the TwiteAnimals : an open access journal from MDPI · 2026Article
- Coupling Artificial Intelligence with Proper Mathematical Algorithms to Gain Deeper Insights into the Biology of Birds' Eggs.Animals : an open access journal from MDPI · 2025Article
- Accurate calculation of the content volume, density and original weight of museum curated eggs.Scientific reports · 2024Article
- Brood parasitism and host-parasite relationships: Cuckoos adapt to reduce the time of hatching ahead of host nestlings by increasing egg thickness.International journal for parasitology. Parasites and wildlife · 2024Article
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Authors and funding
3 authors.
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Abstract
Bird eggs can be spherical, ellipsoid, ovoid, or pear-shaped (pyriform), the latter being the most complex. There is however no unambiguous evolutionary/adaptive explanation for this final, exotic shape. We hypothesized that pyriform eggs have a larger surface area-to-volume ratio (S/V) that may be a criterion for increased embryo metabolism. By integrating mathematical approaches, we confirmed this to be the case and developed a model of the egg metabolic rate defined as the ratio of S/V to its maximum possible value, depending on egg length. We found this to be inversely proportional to the egg incubation period and concluded that the complex pyriform shape is most likely due to embryo metabolism increase and, as a result, a reduction in the incubation period and shortened hatching time. As a result of this study, we conclude that some avian eggs are pyriform as this may attain a larger S/V ratio making them grow and hatch quicker.
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