# Naturally Selected (DD-432)

> Storks often lay several eggs that hatch days apart, so chicks differ in size. When food is scarce, parents may kill or eject the weakest chick, focusing care on those most likely to survive; biologists call this brood reduction. White storks (Ciconia ciconia) have been filmed throwing chicks from nests. The footage shows a stork pushing a chick out of a nest.

- Department: Nature
- First published: 2024-12-18
- Last updated: 2024-12-18
- Permalink: https://detailenjoyer.com/case/naturally-selected/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-432-F01**: Several eggs. _(Write-up · Exhibit A (Eggs))_
- **DD-432-F02**: Days apart. _(Write-up · Exhibit B (Hatching))_

## Write-up

Stork parents sometimes push a weak chick out of the nest. Biologists call it brood reduction.

1. **Eggs**: Several eggs.
2. **Hatching**: Days apart.
3. **Food**: Scarcity drives it.
4. **Term**: Brood reduction.
5. **Storks**: White storks do it.

## Related case files

- [Avian Siblicide (DD-587)](https://detailenjoyer.com/case/avian-siblicide/): I linked more sibling rivalry in birds

## Reel vs. record

- **Note**: None needed.

## Video: Naturally Selected: Stork Parents Sometimes Push a Weak Chick Out of the Nest

- Duration: 23.5 s · Published: 2024-12-18
- File: https://detailenjoyer.com/assets/videos/DDunn0FJ0q0.mp4

### Transcript

Did you know? Storks, like many other birds, may discard immature or weaker chicks under certain circumstances. This behavior, known as brood reduction, occurs when parents prioritize their resources for the healthiest offspring. To ensure their survival, storks often lay multiple eggs, but the hatchlings may not develop equally. If food is scarce or environmental conditions are harsh, the parents may push weaker chicks out of the nest, focusing on those with a better chance of thriving. NOW YOU KNOW!

## Questions & answers

**Q: What is it called?**  
A: Term. _(Source: Write-up · Exhibit A (Eggs) · Wikipedia: Brood reduction)_

**Q: Why do chicks differ?**  
A: Asynchronous. _(Source: Write-up · Exhibit B (Hatching) · Wikipedia: Brood reduction)_

**Q: When is it likely?**  
A: Resources. _(Source: Write-up · Exhibit C (Food) · Wikipedia: Brood reduction)_

**Q: Which chick is removed?**  
A: Survival. _(Source: Write-up · Exhibit D (Term) · Wikipedia: Brood reduction)_

**Q: Which stork is filmed doing it?**  
A: Europe. _(Source: Write-up · Exhibit E (Storks) · Wikipedia: White stork)_

## Sources

- [Wikipedia: Brood reduction](https://en.wikipedia.org/wiki/Brood_reduction)
- [Wikipedia: White stork](https://en.wikipedia.org/wiki/White_stork)

## Cite this case file

Easterling, Marcus. "Naturally Selected." The Detail Department (DetailEnjoyer), case file DD-432, last updated Dec 18, 2024. https://detailenjoyer.com/case/naturally-selected/