Kielder is a name synonymous with space and wilderness. Nestled along the centre of the English-Scottish border, in Northumberland, Kielder Water and Forest Park is home to England’s largest forest and the biggest man-made lake in Northern Europe. It is also part of the UK’s largest International Dark Sky Park. Safe to say, it’s a special place for a number of reasons.  

The Missing Lynx Project’s research has shown that Kielder Forest is part of the forested area that is one of the few places in Britain that would be suitable for a lynx release. But what is Kielder like? The vast expanse of Kielder means that a range of habitats can be found, and the sheer size of these habitats means that there is plenty of space for large populations of wildlife to thrive. It’s big enough that animals can move between areas and forestry blocks in response to felling or storm damage.  

Alongside and within the commercial forestry, there are extensive areas of internationally significant blanket bog (known as the Border Mires), wet heath, more than 1,000 km of river corridors, open water and increasing broadleaved woodland. Species that can be found in Kielder include large numbers of roe deer (the lynx’s preferred prey), foxes, badgers, otters, at least nine species of bats, goshawks, crossbills, adders and more. Several important and long running monitoring projects take place at Kielder, including a 35-year study into tawny owl populations. Golden eagles are even occasionally seen in the area, following their reintroduction to the south of Scotland in recent years.

Famous faces 

One of the most famous residents of the forest is the red squirrel. Kielder is thought to be home to approximately 50% of the remaining English population, a really significant stronghold for an animal that is under pressure due to the introduced, non-native grey squirrel. In 2018, a remote trail camera captured an image of a pine marten in Kielder Forest, the first concrete evidence of their presence in the county for decades. Since then, pine martens have been slowly colonising Kielder Forest and wider parts of Northumberland, though the population is still small.  

Their return could provide a helping hand to our threatened red squirrels, with studies showing that where red squirrels, grey squirrels and pine marten are all present, red squirrel populations may recover and grey squirrel populations decline. The reasons for this aren’t fully understood yet and research is ongoing, but it’s certainly encouraging news that there could be a natural ally in the continuing efforts to protect the red squirrel.  

Another species that has made its way to Kielder Forest after a prolonged absence is the iconic osprey, a fish-eating bird of prey that raises chicks here in summer, before migrating south for the winter. Ospreys were persecuted to extinction in the UK in 1847, but in 1955 a breeding pair (likely from Scandinavia) was found in Scotland. Their numbers gradually started to recover and the birds were often seen flying over Kielder during migration.  

In 2008, Forestry England made the decision to erect some nesting platforms in the forest to see if any of these migrants would be attracted to stay in the area. It worked, and in 2009 the first Northumbrian osprey chicks for 200 years hatched at Kielder. The Kielder population continues to grow and spread, and 124 young ospreys have left Kielder between 2009 and 2024 – a significant contribution to the recovery of this beautiful bird, and a wonderful example of a successful species recovery.  

A helping hand 

Some missing species will not be able to make their way back to Kielder by natural means. The water vole, Britain’s fastest declining mammal, was lost from Kielder in the 1980s. Today, there are only a few small, isolated populations of water voles in Northumberland, typically in the upper stretches of river catchments. The two major factors that led to their decline are habitat destruction and the invasive American mink, which is able to enter water vole burrows, meaning they are unable to escape this predator.  

In 2014, Northumberland Wildlife Trust, Forestry England and Tyne Rivers Trust launched the Kielder Water Vole Heritage project. The project carried out mink monitoring throughout the forest for a period of two years, alongside talking to local communities and capturing memories and the history of water voles in the area. Of over 1,000 records collected from monitoring stations, only one was thought to be a possible mink footprint. Confident that the area was free of any established breeding mink population, the partnership launched the Restoring Ratty project in 2016.  

Over the next five years, more than 2,200 water voles were reintroduced into the Kielder Forest area with the help of an incredibly dedicated team of volunteers, working alongside staff from the three organisations. Surveys and reports from the last few years show that the water voles have settled well into the forest and are starting to spread out, providing hope for the future of the species in Northumberland. Future plans include working to link the Kielder voles with those smaller, isolated populations elsewhere. But, for the moment, work continues to make sure these voles remain common within their Kielder stronghold.  

Could lynx one day join ospreys, pine martens and water voles in a Kielder comeback? The Missing Lynx Project is on a mission to find out. Get monthly updates, along with lynx facts and stories, by subscribing to the project newsletter. 

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