The National Trust is warning that unpredictable weather patterns during the last 12 months have thrown nature into chaos in its annual Weather and Wildlife Review for 2023.

Photo: Beaver kit feeding at the Holnicote Estate on Exmoor

© National Trust Images/Barry Edwards

The 2023 Review says that a dry winter, the warmest June on record, a wet and mild autumn, plus back-to-back storms, have confused wildlife and people alike. With 2023 anticipated to be the warmest year on record, and 2024 already forecast to be even warmer, the Trust says it is sounding the alarm for UK wildlife.

Key highlights in the Review include:

Winter

A dry start to the year did nothing to ease the low water levels caused by a lack of rainfall in 2022. Mild conditions also saw species, such as great crested newts at Dyffryn Gardens in south Wales and common lizards on the Norfolk Broads appear earlier than usual. While flooding in February boosted numbers of waterfowl on the Norfolk Broads, it was risky for small mammals. Similarly, rising river levels, seen again at the end of the year, helped ducks and pintails but made life more difficult for moles, voles and mice.

Spring

A cool start to March delayed the start of the blossom season. But once temperatures rose, vibrant displays of blossom could be seen across most areas of the UK. Hawthorn was abundant at many of the places we care for. The persistent cold at the beginning of the season also affected butterflies and other pollinators, forcing them to emerge later than usual. Brimstone butterflies, usually seen at Felbrigg Hall, Garden and Estate and Sheringham in Norfolk as early as February, were not spotted until well into March.

Summer

In the summer, the UK recorded its warmest ever June. The River Derwent in the Lake District's Borrowdale Valley, traditionally the wettest area of England, dried out for the third consecutive year. Sea temperatures reached new highs. The European Space Agency reported temperatures 3 to 4C above average, and the waters were warmer than usual off the north-east coast of England and Scotland and the north-west Ireland.

July was also the hottest month ever recorded globally, 1.5C warmer than average.

Early flowering meadow plants bloomed quickly during the hotter months. Some plant species such as yellow rattle bloomed up to eight weeks ahead of schedule.

On the Suffolk coast, the dry weather meant our rangers had to manually dampen sites to support wading birds and their chicks. Meanwhile, we worked hard to try to help seabird colonies at risk from bird flu at coastal places in Northumberland, Dorset and Wales.

Autumn

Autumn was warmer and wetter than average with huge levels of rainfall, especially in October. Storms Babet and Ciaran battered parts of the country, causing serious flooding affecting people, nature, landscapes, buildings and coastlines.

Temperatures didn't drop until late in November, causing confusion for several species. The red deer at Holnicote delayed their rutting period, and plants at Glendurgan Garden in Cornwall flowered out of season. Warmer autumns such as these could mean dormice, like those we introduced at Calke Abbey in Derbyshire this summer, emerge early from hibernation, using up vital energy stores.

Ben McCarthy, National Trust Head of Nature Conservation and Restoration Ecology commented:

“The incremental shifts we’re experiencing in terms of our seasons extending may not feel like much in a 12-month period, but over a decade the changes are extremely significant.”

The Review is drawing attention to the following wildlife losers in 2023.

Seabirds

Bird flu returned to the Farne Islands this year, proving fatal for a range of seabirds. However, quick action was taken to collect dead birds to try and stop the spread, and fatalities fell by 39 per cent on last year.

Worryingly, the disease spread to five more seabird breeding sites around the UK, including Brownsea in Dorset, Cemlyn in north Wales, and Long Nanny in Northumberland, which is home to Britain’s largest mainland colony of Arctic terns, as well as a small colony of little terns. In total, more than 7,000 dead birds were collected from coastal places in our care.

The only exception was Blakeney Point on the Norfolk coast, where the little tern population remained largely unaffected and saw the highest number of chicks since 2020.

Mosses and liverworts

The consequences of last year's drought showed in the health of many mosses and liverworts in the temperate rainforest at Lydford Gorge on the edge of Dartmoor in Devon. Temperate rainforests have a humid climate, and the drought in 2022 and the dry start to 2023 caused many of these plants to dry up. They can sometimes recover, but despite the higher levels of rain since July, they don’t appear to have survived.

Red deer

The warm autumn weather is affecting the rutting behaviour of red deer. The mating ritual normally begins in September, but warm weather is delaying it further into the winter. As a result calves are born later in the year, in summer rather than spring, potentially giving them less time to grow and put on the weight and fat needed to survive the winter.

Wildlife that experienced mixed fortunes in 2023

Butterflies

Sunny and settled weather occurred at just the right time for the flight period of the heath fritillary butterflies at the Holnicote Estate and the large blues at Collard Hill, both in Somerset. The grizzled skippers at Calke Abbey in Derbyshire were less lucky. A warm June impacted the plants they rely on for food, and numbers never recovered when bad weather thwarted the next phase of local reintroduction efforts.

Heathlands

Dunwich Heath in Suffolk lost over 60 per cent of its heather due to the extreme heat, drought and high numbers of heather beetle in 2022. While the rains that came in late this summer do seem to have allowed for some recovery, rangers estimate that around 40 per cent of the famous heathland is unlikely to recover. This also affects many other species, such as the rare Dartford warbler, whose recorded numbers in 2023 dropped from 30 breeding pairs to under 20.