London’s first beaver reintroduction site …

(just behind Maccy D’s!)

As part of a ‘Rewilding Season’, including a speaker meeting evening and a members’ film night to see the Knepp Estate film, Wilding, MHSG went on a beaver hunt … in London!

A sweaty June tube ride, a tramp through tired, interwar suburbia, navigating a sprawling retail estate in Greenford, with instructions to meet behind a Macdonald’s car park …

Not the obvious setting for a guided tour of London’s first beaver reintroduction site. Particularly not one called Paradise Fields.

Yet this is where we met up with Digby – one of the passionate, encyclopaedic team at Citizen Zoo, who are behind this rewilding project in Ealing. Which, it turns out, proves to have been aptly named.

20 years ago, this 10 hectare basin was playing fields earmarked as a flood control area. When that plan was dropped, nature was left to reclaim its own, and an oasis of wood, grass and wet lands sprang up.

Today, reeds rustle in the breeze, insects hum in volume, wild flowers bob in brambly hedgerows … and somewhere Europe’s largest rodent resides. For the first time since the 1600s.

A brief history of beavers and their bottoms…

From a population of around 5 million across Eurasia, beaver numbers had shrunk to 1,200 by the beginning of the 20th century, surviving in pockets of Ukraine and Germany. And only the North American and the Eurasian beavers have survived at all, from around a hundred distinct species. One the size of a Mini Cooper, we were alarmingly informed.

We probably all know that they were hunted to extinction for their waterproof fur – perfect for hats and coats – but their covetable anal glands are possibly less well known! The beaver’s regular diet of willow, Digby tells us, contains a natural aspirin, and their anal glands were thus used as an analgesic.

MHSG members in the “beaver airlock”

Paradise Fields …

And with that thought … we enter the site through a tunnel, lined with giant murals of the animals we are headed for: great crested newts, bats, dragon flies, harvest mice and, of course, the Eurasian beaver.

It’s gated at each end, described by Digby as “the beaver airlock” because beavers, it appears, are quite the absconders. One recently washed up (alive!) in Sandwich Bay, for example, another rocked up in Wolverhampton, and there has been a case of a beaver swimming 40km across the Baltic Sea.

1.2km of beaver fence also had to be erected, then, before the five beavers that now call Paradise Fields home could be released – with much mayoral fanfare – on October 11th 2023.

Citizen Zoo applied for them in 2021 through the Beaver Trust, who undertook two years of biodiversity checks on the site, with further stipulations including the need for two hectares per beaver and an incubation period prior to release.

A light beaver snack

As crepuscular animals (they emerge at dawn), we were unlikely to see them, but we did see plenty of evidence, a trail of characteristically 45-degree gnawed wood; and, incredibly, signs of the positive impact they are already having on the environment after just eight months.

A dam!

Nature’s eco-engineers …

Their first dam was constructed within hours of their arrival, because, as Digby explained, beaver’s hate the sound of running water, which will immediately trigger the dam building instinct. Such that pet beavers (only in America!) have been known to barricade doorways with toys and moveable pieces on hearing a tap. The noise must have been unbearable in Canada then, where a beaver dam exists that is 800m wide.

Dams, however, are your ultimate eco-architecture. They filter the water, create ponds that slow the water flow, reducing erosion and stopping sediment flowing downstream. Indeed, by holding back the silt they help to lock up carbon, while the new plant growth encouraged by the ponds creates a carbon sink. Meanwhile, their tree gnawing and felling is a natural thinner and catalyst for healthy regrowth.

Of course, the beaver hasn’t planned all this specifically. But plan he has, nevertheless. Incredibly thoroughly.

Playing the long game with a ‘ring barked’ tree

Nature’s planners …

The new growth promotion is essentially a larder for him, the pond a refuge from predators, the banks the perfect burrowing place for their ‘bell jar’ design lodges.

And he plans well ahead.

We saw a ‘ring barked’ willow, bearing a gnawed ring which will slowly kill the tree over a couple of years. Despite the ‘eager beaver’ moniker, he sure can wait. We also saw a canal, pre-dug from a stream to a tree (evidently selected for future felling), enabling easy logging when the tree’s number is up.   

And he is brilliantly evolved for all this important work. A waterproof coat, third eye lid ‘goggles’, webbed hind feet and nostrils located on the top of a flat skull, make him an aquatic superstar, able to hold his breath for 15 minutes, from lungs that have three times the capacity of a human.

His teeth (which keep growing, so must keep gnawing), are strengthened with iron, accounting for the orange colour and allowing him to access a tree’s sugars and nutrients behind the bark. And his intricate dam building work is facilitated by a unique, opposable ‘little finger’. What incredible animals!

Digby demonstrates that perfectly adapted skull shape

Big Mama …

I say ‘he’, but beavers are very definitely a matriarchal society. The Ealing Five are presided over by 30kg and 1.4 metres of ‘Big Mama’, as the team has named her, who will have no qualms about driving out any competition from other breeding pairs.

She arrived from Argyllshire with a younger boyfriend, a stepdaughter and two kits, driven down by beaver guru, Dr Roisin Campbell-Palmer; who pit-stopped overnight, leaving the beavers caged in a specialist van, at – you guessed it – a Travel Lodge.

So why were Citizen Zoo so keen to bring them into their rewilding project?

Regenerating landscapes …

Beavers are a keystone species – ecosystem engineers – they modify their environment, support other animals and reduce the risk of floods. So Ealing did get their flood defences after all, for a fraction of the anticipated cost. In fact, hydrologists at the University of Exeter have calculated that beavers deliver a 30% flooding mitigation.

Incredibly, Citizen Zoo has seen an immediate impact on the biodiversity at Paradise Field, which Digby describes as “unrecognisable” from eight months ago.

Their wetlands species have noticeably increased, including reed warblers and cherry warblers, amphibians and insects like dragonflies, whose nymphs rely on water. The beavers have already created small oxbows in the waterways, unnaturally straightened by man; again slowing water flow in doing so, and developing new habitats. An eco-system perfect for the team’s next planned reintroduction, in fact: water voles.

A beaver ‘oxbow’

What next …?

There are thought to be around 1 to 2,000 beavers currently in the UK, with wild communities in Kent, Oxfordshire and Devon. And while Digby feels that there has been a “paradigm shift” in the public’s perception of beavers, from destructive to constructive, “we have to transition to the German model of beaver acceptance, where landowners are compensated for any land affected.”

In the meantime, Citizen Zoo is hoping that their beavers will have already bred, and are planning further London beaver reintroductions, with longer term ambitions to create rewilding corridors linking with other such projects. And as pollution resistant animals, seemingly unfazed by the noises and lights of urban life, beavers are once again proving themselves to be remarkably adaptable friends.

How you can get involved …

In the short term, Citizen Zoo welcome visitors at dusk to try and spot the beavers from their viewing platform – just turn up – or you can book one of the fascinating and highly recommended guided tours with them as we did, by emailing direct. And they are also always looking for volunteers to help with their projects.

On screens, the Ealing Beaver Project will be launching their own web site soon, but you can currently find out more, sign up for their newsletter and contact them through the Citizen Zoo one.  

And look out for “Beavers in Paradise”, a short film by Matt Brierley, which will be screened at Ealing Picturehouse towards the end of July and thereafter available online.

Until then .. beaver and out.

Paradise Fields’ project partners:

Citizen Zoo, Ealing Council, Horsenden, and the Ealing Wildlife Group

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