The first sign that something has changed in Glen Affric is a small, dark head cutting a silent V across Loch Beinn a Mheadhoin at dusk.

It belongs to a beaver kit — one of seven animals released into the Highland glen this spring, the first of their kind to swim these waters in four hundred years. A few hundred miles south-east, on a Perthshire pine, a female osprey called Blue 210 is busy "nestorating" with her mate after a 3,000-mile flight from west Africa. And off the Sussex coast, in waters Scotland's marine scientists are watching closely, a kelp forest flattened by decades of trawling is quietly stitching itself back together.

Twenty years ago, none of this looked likely. Today, it is the everyday business of a quietly extraordinary conservation movement — and a new report from The Wildlife Trusts says Scotland has been at the heart of it.

A £31m bet that paid off

The two-decade programme, bankrolled by £31 million raised by players of the People's Postcode Lottery, has funded hundreds of projects across Britain — from urban forest schools to landscape-scale rewilding. The Wildlife Trusts this week marked the anniversary by publishing a roll-call of results that would have seemed fantastical in 2005.

Otters now turn up at 91% of surveyed sites in Northumberland. Millions of seabirds are protected on the Scottish island of Handa. More than a thousand isolated and anxious people have been helped back into daily life through a single nature-prescribing scheme on Morecambe Bay. Seagrass is creeping back into the Solent from 1,025 carefully dropped "seed bombs."

"Every single staff hour funded and hectare of countryside restored all adds up to a united mission to save our natural world for wildlife and people," said Craig Bennett, chief executive of The Wildlife Trusts. "The climate change challenge facing us all is immense and this long-term support has helped Wildlife Trusts rise to it."

Beavers: from trial to triumph

Scotland's beaver story is the headline act. The original Scottish Beaver Trial, launched with Postcode Lottery backing, brought the species back to Britain after a 400-year absence. From a handful of animals in Knapdale, the Scottish population has swelled past 2,000 — and conservationists are now moving them into new catchments to spread the benefits.

The Glen Affric release earlier this month was carried out by Forestry and Land Scotland and the charity Trees for Life. "As we saw the beavers released into the loch, we were watching a moment of wildlife history," said Steve Micklewright, Trees for Life's chief executive. "It offers hope for tackling the nature and climate emergencies, and a better future for biodiversity and people."

Dr Roisin Campbell-Palmer, head of restoration at the Beaver Trust, who carried out the translocation, said each new river system reclaimed brings Scotland "closer to its 2045 goal of a nature-rich, resilient future."

Ospreys, season after season

At Loch of the Lowes in Perthshire, the Scottish Wildlife Trust's famous osprey nest — visible to the world through a live webcam — has had another dramatic spring. Returning female Blue NC0 touched down on 18 March, kicking off weeks of "skydancing, scrapping and even a few mating attempts," according to the Trust's PR and communications manager Ian McNab.

By 8 April, last year's breeding male LM24 had reunited with Blue 210. The pair have since been seen sharing pike on the nest, and eggs are expected within days.

Kelp, bison and the bigger picture

Beyond Scotland, the same fund has paid for breakthroughs the Scottish projects are already learning from. The Sussex Kelp Recovery Project — the UK's largest marine rewilding effort — is seeing mussel beds stretch more than a kilometre and Black Sea Bream return after a 2021 ban on bottom trawling.

In Kent, a herd of European bison reintroduced in 2020 has produced seven calves and is rewriting the rulebook on large-herbivore rewilding. "This isn't just a local project," said project lead Cristina Juan of Kent Wildlife Trust. "We are proof of concept that conservation can be done differently. We've learned so much about bison that we're writing a manual."

Back at Kielder, where two Exmoor ponies named Puddles and Prancer started the whole adventure in 2005, Northumberland Wildlife Trust chief executive Mike Pratt sounded almost disbelieving.

"From this very first, tiny project, great things have arisen," he said. "It's been on a massive scale and has made an incredible difference."

In Glen Affric, the kits don't know any of that. They just keep swimming.