# European Bison — Facts, Threats & Conservation

*Bison bonasus (Linnaeus, 1758) — family Bovidae*

> The European bison (Bison bonasus) is Europe's largest land mammal, restored from around fifty-four captive animals when the last wild individual died in 1927 to more than 6,800 wild bison today through captive breeding and reintroduction.

**IUCN status:** Near Threatened — restored from ~54 captive animals in 1927 to 6,800+ wild  ·  **WARN range:** Poland, Belarus, Russia, Romania, Ukraine and reintroduced populations across Europe

## Quick facts
| Fact | Value |
| --- | --- |
| Weight | 400–920 kg |
| Habitat | Deciduous and mixed forest with open glades |
| 1927 | Last wild individual killed; ~54 captive survivors |
| Wild population | 6,800+ and growing |
| Also called | Wisent |
| Diet | Browser — leaves, bark, shoots, woodland grasses |
| Main threats | Habitat loss, poaching, inbreeding, fragmentation |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Family:** Bovidae
- **Genus:** Bison
- **Species:** Bison bonasus

## Conservation status
- **Status:** Near Threatened
- **Population:** 6,800+ wild; several thousand in captivity
- **Trend:** Increasing through reintroduction and breeding
- **Assessed:** 2020
- **CITES:** Appendix III (Belarus)
- Restored from around fifty-four captive animals in 1927. Populations are growing but remain genetically bottlenecked and require active management.

## Key facts: European Bison
- European bison are Europe's largest land mammal, adapted to forest rather than open grassland.
- The last wild individual was shot in 1927; the entire species then survived in captivity from around fifty-four animals.
- Captive breeding and reintroduction have rebuilt the wild population to more than 6,800 animals.
- The species is Near Threatened — a major recovery, but populations remain fragmented and actively managed.
- Two genetic lines persist — the Lowland-Caucasian and the Bialowieza line — from the captive founder pool.
- Forest habitat loss, poaching and inbreeding depression remain concerns despite the population increase.
- Reintroduction continues across Europe, with herds now in Germany, Romania, Spain and other countries.

## From extinction to six thousand
The European bison's recovery is among the most successful mammal restorations in history. Wild hunting eliminated the species across its range during the nineteenth and early twentieth centuries. The last confirmed wild animal — a Caucasian bison — was killed in 1927 in the western Caucasus. Every European bison alive at that moment was in a zoo or private collection.

The captive population numbered around fifty-four animals, descended from just twelve founders. Two breeding lines were maintained: the Lowland-Caucasian line and the Białowieża line, reflecting the two subspecies that had existed in the wild. Careful managed breeding minimised inbreeding and preserved what genetic diversity remained. Reintroduction to the Białowieża Forest in Poland began in 1952, and the wild population grew steadily from there.

By the 2020s, more than 6,800 wild bison roamed forests across Poland, Belarus, Russia, Ukraine, Romania, Germany and other countries. Reintroduction continues — new herds established in the Netherlands, Spain and the Czech Republic — but each release requires years of preparation, habitat assessment and post-release monitoring. International pedigree coordination keeps breeding and reintroduction aligned across the continent. Without that coordination, the recovery would have stalled long ago.

## A forest bison, not a prairie bison
European bison are not American bison in a different continent. They are forest animals: browsing on leaves, bark, shoots and woodland grasses rather than grazing open prairie. Herds are smaller — typically fewer than thirty animals — movements are less dramatic, and the habitat they require is deciduous and mixed forest with open glades and meadows where sunlight reaches the ground.

This matters for reintroduction. European bison need forest — not just any land, but woodland with enough understorey browse and open areas for grazing. Reintroduction projects in Germany's Rothaar Mountains, Romania's Vânători-Neamț and Spain's San Cebrián have succeeded where suitable forest exists. Projects on unsuitable land — open grassland without tree cover, or forest too dense for ground vegetation — have failed. Bison released into pine plantations without understorey browse struggle to find food through winter.

European bison also shape the forest they inhabit. Their browsing opens the understorey, their wallowing creates small clearings, and their dung supports invertebrate communities. In the Białowieża Forest — the largest remaining tract of old-growth lowland forest in Europe — bison have been part of the ecosystem for decades since reintroduction, and their ecological role is increasingly studied as reintroduction expands to other European woodlands.

## The genetic bottleneck
Every European bison alive today descends from around twelve founders. That is an extraordinarily narrow genetic base for a large mammal, and inbreeding depression — reduced fertility, weaker immune function, lower calf survival — has been a documented concern throughout the recovery.

Managed breeding programmes track pedigree carefully and exchange animals between herds to maintain diversity. The two genetic lines — Lowland-Caucasian and Białowieża — are managed to preserve distinct ancestry while avoiding further inbreeding. Hybridisation between the lines is controlled: some herds are maintained as pure Białowieża, others as Lowland-Caucasian, and a third category of mixed-line herds exists for genetic management. Pedigree records for every captive and reintroduced bison are maintained centrally.

The result is a population that has grown numerically but remains genetically vulnerable. A disease outbreak, a severe winter, or a poaching event in a small reintroduced herd can remove genetic diversity that took decades to build. The European bison recovery is measured in headcount, but the genetic health of the species requires continuing active management that cannot be discontinued without risk. Future reintroductions must draw from genetically managed source herds, not simply from whichever reserve has surplus animals.

## What Near Threatened means here
The IUCN Near Threatened listing reflects genuine progress and remaining risk. More than 6,800 wild bison is a remarkable number compared with fifty-four captive animals in 1927. But populations are fragmented across isolated reserves and reintroduced sites, poaching occurs in eastern parts of the range — particularly in the Caucasus and Ukraine — and habitat quality varies sharply between well-managed reserves and marginal forest.

Reintroduction continues — new herds established in countries where the species had been absent for centuries — but each new population requires long-term management, habitat protection and genetic monitoring. The European bison is no longer on the brink, but it is not yet a species that can be left alone. Supplementary feeding in harsh winters, veterinary intervention, and anti-poaching patrols are part of normal management at most wild sites across its range.

The Near Threatened listing also acknowledges that the species' range remains far smaller than its historical extent. European bison once ranged from Spain to the Caucasus; today they occupy a fraction of that area, concentrated in central and eastern Europe. Full ecological restoration — bison as a widespread forest species — remains a long-term goal, not a current reality, and every new reintroduction site adds management obligations that persist for decades after the first animals are released.

## What WARN does
WARN publishes free, sourced species education for recovery stories that are real but incomplete. The European bison went from fifty-four captive animals to more than six thousand in the wild — a genuine success that still requires active management, which is the detail most retellings leave out.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

## Frequently asked questions: European Bison
### Are European bison extinct?
Not anymore. The last wild individual was shot in 1927, after which the entire species survived in captivity from around fifty-four animals. Captive breeding and reintroduction have rebuilt a wild population of more than 6,800 bison across Europe.

### How many European bison are left?
More than 6,800 in the wild across Poland, Belarus, Russia, Romania and reintroduced sites in other European countries, plus several thousand in captivity. The wild population continues to grow through reintroduction.

### What is the difference between European and American bison?
European bison are forest-adapted browsers, eating leaves, bark and woodland vegetation. American bison are prairie grazers. They are separate species within the genus Bison, with different ecology, body shape and horn curvature.

### Why are European bison Near Threatened?
Despite recovery from near-extinction, populations remain fragmented, genetically bottlenecked from a tiny founder pool, and vulnerable to poaching and habitat loss. The listing reflects major progress that is not yet secure without continued management.

### Where can you see wild European bison?
In the Bialowieza Forest of Poland and Belarus, the Bieszczady Mountains, and reintroduced herds in Germany, Romania, Spain, the Netherlands and other European countries where suitable forest habitat exists.

### How did European bison recover from fifty-four animals?
Managed captive breeding in zoos and reserves preserved the species after the last wild death in 1927. Two genetic lines were maintained from twelve founders. Reintroduction began in 1952, and wild populations grew steadily with continued releases and protection.

### Where can I compare this recovery with extinctions that finished?
WARN profiles finished extinctions with living parallels at /wildlife-guides/extinct-animals/, and species that still survive only in captivity at /wildlife-guides/extinct-in-the-wild/ — the categories the European bison left behind.

## Sources
- [IUCN Red List — Bison bonasus](https://www.iucnredlist.org/species/2815/45156679)
- [Natural History Museum — European bison](https://www.nhm.ac.uk)

---
Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/european-bison