# Smew (*Mergellus albellus*)

Canonical page: https://creaturedata.com/animals/smew  
Data as of: 2026-11-11

The smew (Mergellus albellus), also called the White nun, is a bird in the waterfowl subgroup and the family Anatidae, order Anseriformes. It is a small bird with an adult body mass of 608.5 g, from 568 g to 667.2 g in reported values, and a wingspan of 62 cm. The smew is a migratory, aquatic carnivore and aquatic predator that lives in wetland habitat, with a geographic range of 11,990,000 km². It lays 8 eggs per clutch with one clutch per year, incubates them for 27.5 days, and is listed as Least Concern on the IUCN Red List.

## Quick facts

| Fact | Value |
|---|---|
| Weight | 568 g – 667.2 g |
| Length | Not recorded |
| Wingspan | 62 cm |
| Lifespan | 10 years |
| Diet | Aquatic predator |
| Main food | Not recorded |
| Habitat | wetland |
| Egg incubation | 27.5 days |
| Young per litter or clutch | 8 |
| Age at maturity | 23.9 months |
| Litters or clutches a year | 1 |
| Lifestyle | Aquatic |
| Migration | Migratory |
| Conservation status | Least Concern (IUCN) |
| Countries on record | Not recorded |

## Classification

- kingdom: Animalia
- phylum: Chordata
- class: Aves
- order: Anseriformes
- family: Anatidae
- genus: Mergellus
- species: *Mergellus albellus* (Linnaeus, 1758)

Synonyms: *Albellus maculosus*, *Margellus albellus*, *Mergullus albellus*, *Mergus albellus*, *Mergus albellus*, *Mergus albellus albellus*, *Mergus asiaticus*, *Mergus minutus*, *Mergus tinus*

## Common questions

### How heavy is the smew?

The smew has an adult body mass of 608.5 g, with reported values from 568 g to 667.2 g. Its wingspan is 62 cm.

### What does the smew eat?

The smew is an aquatic predator and a carnivore.

### Is the smew endangered?

No. The smew is listed as Least Concern on the IUCN Red List, which is not a threatened category.

### How long does the smew live?

The smew has a lifespan of 10 years.

### How many eggs does the smew lay?

The smew lays 8 eggs per clutch and has 1 clutch per year. The eggs are incubated for 27.5 days.

### What kind of animal is the smew?

The smew is a bird in the waterfowl subgroup, belonging to the family Anatidae and the order Anseriformes. It is migratory and lives in wetland habitat.

### Who described the smew?

The smew was described by Linnaeus in 1758; its scientific name authority is written (Linnaeus, 1758).

## Sources

- [An amniote life-history database to perform comparative analyses with birds, mammals, and reptiles](https://doi.org/10.6084/m9.figshare.3563457.v1), CC0 1.0, E096-269. Myhrvold, N.P., Baldridge, E., Chan, B., Sivam, D., Freeman, D.L. & Ernest, S.K.M. (2015) An amniote life-history database to perform comparative analyses with birds, mammals, and reptiles. Ecology 96: 3109. https://doi.org/10.1890/15-0846R.1. Data: https://doi.org/10.6084/m9.figshare.3563457.v1
- [AVONET: morphological, ecological and geographical data for all birds](https://doi.org/10.6084/m9.figshare.16586228.v7), CC BY 4.0, v7. Tobias, J.A. et al. (2022) AVONET: morphological, ecological and geographical data for all birds. Ecology Letters 25: 581–597. https://doi.org/10.1111/ele.13898. Data: https://doi.org/10.6084/m9.figshare.16586228.v7
- [Catalogue of Life eXtended Release](https://www.checklistbank.org/dataset/316691), CC BY 4.0, 2026-10-16 XR. Catalogue of Life (2026). Catalogue of Life eXtended Release, version 2026-10-16 XR. Catalogue of Life Foundation, Amsterdam, Netherlands. https://doi.org/10.48580/dgzlf
- [Wikimedia Commons](https://commons.wikimedia.org), per file (CC0 / public domain / CC BY green, CC BY-SA amber, anything else not displayed), 2026-11-11. Wikimedia Commons contributors. Wikimedia Commons. https://commons.wikimedia.org (each file credited to its author under its own licence).
- [Wikidata](https://www.wikidata.org), CC0 1.0, 2026-11-11. Wikidata contributors. Wikidata. https://www.wikidata.org (data retrieved via the Wikidata Query Service).
- [Wikipedia (English)](https://en.wikipedia.org), CC BY-SA 4.0, 2026-11-11. Wikipedia contributors. Wikipedia, The Free Encyclopedia. https://en.wikipedia.org (text under CC BY-SA 4.0; each block names its article and revision).

Cite as: Smew (Mergellus albellus). Retrieved from https://creaturedata.com/animals/smew