# Murmuration (DD-653)

> Murmurations are the swirling pre-roost flocks of common starlings (Sturnus vulgaris), usually seen on autumn and winter evenings. In 2008, the STARFLAG team in Rome reconstructed flocks of thousands of birds in 3D. They found each starling responds to a fixed number of nearest neighbors, about six or seven, rather than to every bird within a set distance. This 'topological' rule helps a flock stay together even as its density changes sharply under attack. A 2017 citizen-science study by Goodenough and colleagues analyzed thousands of UK reports. It found murmurations were bigger and lasted longer when predators such as peregrine falcons and sparrowhawks were around, which supports the 'safety in numbers' explanation. The study found little support for the idea that birds gather to keep warm. Studies of falcon attacks show waves of dark and light rippling away from the predator, and more waves were linked to fewer successful attacks. The idea that murmurations share information about feeding sites is still only a hypothesis.

- Department: Nature (also Science)
- First published: 2025-09-23
- Last updated: 2025-09-23
- Permalink: https://detailenjoyer.com/case/murmuration/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-653-F01**: Each starling in a murmuration tracks about six or seven nearest neighbors. _(Write-up · Exhibit B (Six or seven neighbors))_
- **DD-653-F02**: Murmurations get bigger and last longer when predators are around. _(Write-up · Exhibit D (Predators drive it))_

## Write-up

Seven neighbors steer the flock. Starlings track six or seven birds, not a set distance.

1. **What a murmuration is**: Murmurations are the swirling flocks common starlings form before settling to roost, mostly on autumn and winter evenings.
2. **Six or seven neighbors**: 3D tracking of flocks in Rome found each bird responds to about six or seven nearest neighbors, not to all birds within a set distance.
3. **Why that matters**: That rule keeps a flock together even when its density changes sharply under a predator's attack.
4. **Predators drive it**: Thousands of UK citizen-science reports showed murmurations were bigger and lasted longer when raptors were around. They gave little support to the idea that birds gather to keep warm.
5. **Waves that confuse**: During falcon attacks, waves ripple away from the predator, and more waves were linked to fewer successful attacks.

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## Reel vs. record

- **Wrong rule**: starlings don't keep a 'set distance'. Each tracks a fixed number of neighbors (about six or seven), whatever the distance (Ballerini et al., 2008).
- **Unclear**: 'communication about good feeding grounds' is only a hypothesis. The best-supported explanation is protection from predators.
- **Missing evidence**: a 2017 citizen-science study found larger, longer murmurations when raptors were around, and little support for the idea that birds gather to keep warm.
- **Missing seasonality**: murmurations mostly happen on autumn and winter evenings, before the birds roost.
- **Missing detail**: waves ripple away from an attacking falcon, and more waves were linked to fewer successful attacks (Procaccini et al., 2011).

## Video: Murmuration: Seven Neighbors Steer the Flock

- Duration: 26.8 s · Published: 2025-09-23
- File: https://detailenjoyer.com/assets/videos/DO96gObEV31.mp4

### Transcript

DID YOU KNOW? A starling murmuration is the mesmerizing aerial display created when thousands of starlings swoop and swirl in synchronized patterns, moving as if they were a single living cloud. These flocks form at dusk, often near roosting sites, and scientists believe the behavior offers safety in numbers against predators like falcons, as well as communication about good feeding grounds. Each bird follows simple rules, keeping a set distance, matching speed, and aligning with its neighbors. NOW YOU KNOW!

## Questions & answers

**Q: Roughly how many neighbors does each starling track?**  
A: About six or seven. _(Source: Write-up · Exhibit B (Six or seven neighbors) · Ballerini et al. (2008), Interaction ruling animal collective behavior depends on topological rather than metric distance, PNAS)_

**Q: What did the 2008 study find the rule depends on?**  
A: Topological distance, meaning number of neighbors. _(Source: Write-up · Exhibit B (Six or seven neighbors) · Ballerini et al. (2008), Interaction ruling animal collective behavior depends on topological rather than metric distance, PNAS)_

**Q: What makes murmurations bigger and longer, according to the 2017 study?**  
A: Raptors nearby. _(Source: Write-up · Exhibit D (Predators drive it) · Goodenough et al. (2017), Birds of a feather flock together: insights into starling murmuration behaviour revealed using citizen science, PLOS ONE)_

**Q: When are murmurations mostly seen?**  
A: Autumn and winter evenings. _(Source: Write-up · Exhibit A (What a murmuration is) · Goodenough et al. (2017), Birds of a feather flock together: insights into starling murmuration behaviour revealed using citizen science, PLOS ONE)_

**Q: What ripples through a flock during a falcon attack?**  
A: Waves that spread away from the predator. _(Source: Write-up · Exhibit E (Waves that confuse) · Procaccini et al. (2011), Propagating waves in starling flocks under predation, Animal Behaviour)_

## Sources

- [Ballerini et al. (2008), Interaction ruling animal collective behavior depends on topological rather than metric distance, PNAS](https://www.pnas.org/doi/10.1073/pnas.0711437105)
- [Goodenough et al. (2017), Birds of a feather flock together: insights into starling murmuration behaviour revealed using citizen science, PLOS ONE](https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0179277)
- [Procaccini et al. (2011), Propagating waves in starling flocks under predation, Animal Behaviour](https://doi.org/10.1016/j.anbehav.2011.07.006)

## Cite this case file

Easterling, Marcus. "Murmuration." The Detail Department (DetailEnjoyer), case file DD-653, last updated Sep 23, 2025. https://detailenjoyer.com/case/murmuration/