White storks are returning to the UK. But why is their reintroduction so controversial?

White storks (ciconia ciconia) is a majestic bird with a two-metre wingspan and a huge circular nest.

The recent release of these stunning birds across multiple sites in the UK, with plans for further releases and public consultation, has sparked a debate about whether non-native birds should be part of rewilding projects.

Government consultancy Natural England says white storks are not considered native birds. However, some experts disagree and say it is a native species and was hunted to extinction in the 1400s.

What is a native species?

In the UK, native species are those that have been present for the last 12,000 years. This includes migratory species that breed in or visit the UK. It also includes species that were extirpated by humans but have been reintroduced.

In the UK, a license is needed to bring into the UK any species that is not normally resident or a regular visitor. This is partly because these species can become invasive; This term is used when a species causes significant environmental or socioeconomic harm.

But even if species are not native, they can be valuable for rewilding projects. The white stork’s greatest contribution to rewilding will probably be its ability to stimulate public interest in nature.

Storks are so popular in Europe that there are special stork villages run for tourism purposes and people can see these iconic species up close.

White storks are certainly regular visitors to Britain and are rare but present in the lower fossil record (last 4000 years). This status as a regular visitor means they fall somewhere between native and non-native species; They are not considered a priority for promotion, but no license is required for their release.

Introducing non-native species can cause problems. A good example of this is Japanese knotweed (Reynoutria japonica) was brought to England by the Victorians as an ornamental plant.

It spreads rapidly and damages the structure of buildings and essential services such as water and drainage pipes. Controlling it now costs the UK £247 million every year.

Introduced species are also a major conservation concern, as is the damage done to seabird populations by invasive cats, rats and other animals that feed on their eggs and chicks. If a rewilding project introduces a non-native species, it can become invasive and cause serious degradation of native species already in the environment.

But assessing the impact of introducing new species to nature is important even when a species is considered native.

The Scottish beaver trial was conducted to assess the impact of introducing beavers (Indian fiber) from Norway in 2008. Eighteen years later, beavers are a key part of many rewilding projects from London to large estates in Scotland.

What can white storks add?

White storks are a charismatic species that is viewed positively by most people, which can increase interaction with nature. In Poland, tourists travel hundreds of kilometers to visit white storks, making them valuable for rewilding projects that use tourism to fund them.

Non-native species are also promoted as “ecological analogues”; This means they provide the same ecological function as extinct species.

Steppe bison (bison priscus) They were mixed feeders that roamed the UK during the Pleistocene, meaning they ate a combination of grasses, leaves and the woody parts of plants. Mixed feeders, such as bison, can encourage a patchwork of habitats in a landscape by feeding on a variety of plants and plant parts.

Native steppe bison are extinct in the UK, but projects such as the Kent Wildlife Trust’s Wilder Blean project have introduced the related but non-native European bison (bison goodness) to provide these functions.

Adapting to a warming climate

Better adaptation to future climates is another reason to include non-native species in rewilding projects.

As the UK’s climate changes, species are moving from places where they were thought to be native to new, more suitable areas. Small white butterfly in the south (Pieris mannii) spread northward in Europe and was first seen in England in 2025.

This tiny butterfly successfully made the journey across the ocean, but other species may need human help to move to new regions with more suitable climates.

As an island nation with many locally extinct species, introducing species has formed an important part of the UK’s conservation efforts, including rewilding projects. It is important whether a species is native or not. Although both benefit from rewilding projects, non-native species pose greater risks to local environments and have higher regulatory requirements.

The white stork’s status as a regular visitor may allow them to evade regulatory requirements for non-native species, but the impact on the environment must also be considered.

But installing white storks can have wider benefits to the landscape, as their nests can attract birds such as swallows and swallows.