2020 Climate change extremes result in mixed fortunes for wildlife

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Photo credit: Jeannette Heard, National Trust

Extreme weather events including one of the hottest years on record has once again had a huge impact on UK wildlife in 2020 – but many species have also seen a boost due to the absence of people as a result of lockdown, the National Trust said.

Fewer people during the peak breeding season of spring has seen wildlife move in and plants thrive in locations that would ordinarily be considered tourist hotspots. 

This unintended consequence resulted in previously rare sightings of animals, including peregrine falcons nesting in the ancient ruins of Corfe Castle in Dorset, grey partridges wandering in a car park near Cambridge, and a cuckoo at Osterley in west London – having not been heard here for 20 years. 

Stoats, weasels and hares moved from woodlands to explore the gardens at Plas yn Rhiw, on the Llyn Peninsula. And in the Peak District, curlew were heard in areas that are normally much busier.  In fact, many people reported being more aware of birdsong during the lockdown period.

A buzzard was seen in the orangery at Felbrigg Hall, Norfolk and at Ashridge Forest in Hertfordshire the sound of a grasshopper warbler was recorded in a typically busy dog-walking area.

The absence of people at Blakeney Point in Norfolk provided a boost for the tern colony, with the most successful breeding season for 25 years.  This lack of disturbance, and nests being more sheltered resulted in more chicks surviving the storms in June.  Over 200 little tern chicks fledged, which is the most since 1994.

Common terns had a similarly successful year, with 289 pairs fledging at least 170 chicks, the most since 1999 and sandwich terns arrived late to the site but in high numbers – triple that of 2019 – 2,425 pairs fledging 1,100 chicks.

However, extreme weather events as a result of a changing climate impacted numbers and breeding patterns elsewhere.

The storms in June coupled with high tides and strong winds spelt disaster for the little terns at Long Nanny where nests were washed away.  This seabird has been in serious national decline since the 1980s with fewer than 2,000 pairs now left in the UK.  

The tern colony at Strangford Lough in Northern Ireland struggled this year, with numbers of sandwich, arctic and common tern all lower than 2019 due to predation and high tides.  

Ben McCarthy, Head of Conservation and Restoration Ecology at the National Trust said: “We might have been confined to home for much of the year, but terns, some of our most travelled seabirds carried on with their breath-taking journeys around the globe to reach us. 

“We look after some of the largest colonies of these graceful seabirds, but all our breeding terns are in trouble.  Little terns have been declining since the 1980s, and despite last year’s successful breeding at Long Nanny it was heart-breaking to see so many nests washed away by summer storms. 

“With sea levels rising the area available for terns to nest on is being squeezed.  When several years of summer storms are thrown in, the terns cannot raise enough chicks to keep the population going. 
 
“The contrast in fortunes between the different colonies shows how important it is to look after all their breeding sites.  We need visitors’ help in looking after terns by keeping away from sensitive areas during the breeding season and letting the terns nest undisturbed.  As we expect summer storms to become more frequent due to climate change, our terns need all the help they can get.”

Weather and wildlife in detail

Globally, 2020 is likely to be one of the three warmest years on record.  The mild winter with very little snow, a long dry spring followed by the sunniest and driest May on record created the perfect conditions for some species to thrive, particularly certain species of birds, butterflies and moths.

The mild winter suited the resident Dartford warbler.  Just 11 pairs survived after two particularly cold winters in the 1960s, but it had built its numbers up to more than 3,000 pairs in the early 2000s.  It was then knocked back again by the bitter cold temperatures and snow which arrived with the ‘Beast from the East’ two years ago.  It was seen at the Long Mynd in Shropshire in March for the first time in 20 years.

A ring ouzel also benefited from the milder conditions seen at Cwm Idwal in Snowdonia.  A relative of the blackbird, most spend winter in the Mediterranean but each year one or two risk wintering in the UK.

February was the wettest on record, but despite the record rainfalls, this still wasn’t enough to reverse the drought conditions that some areas were still recovering from after a dry 2019.

The long, warm and dry spring resulted in a particularly good year for blossom with many National Trust gardens and orchards reporting excellent and prolonged displays throughout March, April and May.  The mild winter and early warm weather also resulted in many fruit trees coming into blossom two weeks earlier than normal.

There were also reports from the New Forest of silver-studded blue and small heath butterflies flying up to a month ahead of schedule.  A marsh fritillary was also spotted at The Coombes in Wiltshire for the first time. 

Warm winds from the continent brought record numbers of migrant moths in the summer and early autumn.  Among these was the Clifden nonpareil, one of the UK’s largest moth species, which was recorded on a beech tree at Cliveden, its namesake, again 250 years after it was first found.  After becoming extinct in Britain in the 1960s, this moth has returned to southern England.  It continues to extend its range and this year Calke Abbey in Derbyshire and Ware Cliffs in Dorset also reported their first sightings.  

Conversely, in some places low numbers of butterfly were recorded including Brimstone and Large skipper in the New Forest.  This may be due in part to on-site butterfly transect recordings being delayed because of Covid-19. However, warmer winters may be the cause of decline for some of our butterflies and moths.  Some species have poor breeding years after a mild winter because their parasites or predators survive better. 

Due to a long, dry period in May and June early marsh-orchids and autumn ladies tresses failed to put on their floral displays at Golden Cap in Dorset this year but green winged orchids flowered in their thousands.

Early spider orchids had a good year at nearby Purbeck where the dry conditions impacted the grass, and the meadows flowered in abundance with carpets of pink stork’s-bills.  In contrast, the poor growth of wildflowers and grasses at Long Mynd meant National Trust rangers were unable to cut meadow hay this year to sell.

Ash trees were particularly impacted by this prolonged warm and dry spell, which put them under additional stress, making them more susceptible to ash dieback. Around 40,000 trees will have to be removed from National Trust land this year alone as a result. 

Heather, already under stress from drought conditions in 2019 was more susceptible to dieback caused by the heather beetle.  The beetle will naturally die off in cold winters, but with this year’s warm and wet winter it continued to feed on the moorland plants, putting them under severe pressure and killing them off, affecting swathes of heather across north Wales on the Ysbyty Estate and on the Long Mynd in Shropshire.

The warm summer, with regular rainfall helped reverse in part the drought conditions some areas were starting to see coming at the right time for fruit trees, with fruit able to swell and ripen at the critical time, resulting in a good harvest for many.

The mild and steady conditions in early autumn also resulted in a mast year for many trees, shrubs and hedgerows fruiting in abundance with acorns, conkers, sloes and rowan berries. The culmination of the warm spring, high levels of sunlight and calm conditions in the early autumn also resulted in a good year for autumn colour.

Easterly winds in the autumn resulted in record numbers of migrant birds.  The Rufous Scrub-robin was seen in Britain for the first time in 40 years at Stiffkey saltmarshes in Norfolk and a White’s thrush was recorded on Lundy, a Great snipe at Sandilands, and a Taiga flycatcher at Souter Lighthouse for the first time.

In November, after a period of southerly winds a Crag martin, usually at home in the mountains of southern Europe, appeared on the cliffs at Kingsdown in Kent, staying for almost two weeks, an unusually long stay for this rare bird in the UK.  

Ben McCarthy, Head of Conservation and Ecology Restoration at the National Trust continued: “The impacts of climate change are being felt by our wildlife.  Already under pressure from pollution, habitat loss and inappropriate management, climate change magnifies many of these pressures. 

“Changes to the seasons and changeable weather can play havoc with our wildlife, knocking the delicate balance of nature out of kilter with serious knock on effects for us all. 

“We are already locked into significant environmental change that means snowy winters will become increasingly rare, whilst extreme events in the summer will add stress to our threatened wildlife.

“As ever there will be winners and losers – the Dartford warbler and  marbled white butterfly increasing their range, whilst our land may be more attractive to migrants like the Clifden nonpareil moth.  However, there are more losers than winners with the abundance and distribution of many species continuing to decrease and some groups particularly vulnerable to climate change. 

“At the National Trust we are focusing our efforts on nature’s recovery, not only for its own sake but, as became abundantly clear this year it so important to our own health and well-being. 

“Not only are we focusing on improving the condition of our most important wildlife sites we are also looking to create much bigger areas rich in wildlife, delivering nature-based solutions to the climate emergency that will help us all.  For example, our work restoring blanket bogs not only brings back the unique wildlife of sphagnum mosses and evocative curlews but their peaty soils lock up carbon and help improve water quality reduce flood risk downstream. 

“But we also need to accept that change is afoot and start to manage for the future climate we can expect. This means doing our utmost to protect and conserve our existing wildlife and managing our land sensitively so it can both offer refuge as well as creating opportunities for species on the move but also accommodating change such as erosion to our beaches and shoreline.”

Projects that the conservation charity is currently working on improve habitats for nature include the creation of 25,000 hectares of priority habitat by 2025, its work on river restoration and the planting of 20 million trees over the next decade.

Keith Jones, climate change adviser at the National Trust added: “One of the biggest issues we are facing is sustained levels of warming.  The more heat that’s in the atmosphere the more dynamic it becomes, able to carry more water which is resulting in these more frequent and extreme downpours.

“Increasing levels of wind from storms such as Ciara and Frances all cause damage to the things we care for but are also exposing wildlife to sustained stress.

“We are seeing the consequences of our actions particularly around carbon commissions play out in the natural world through loss, unpredictability and change.  And some of our most treasured landscapes, species and habitats will be lost, change, or move.

“What’s happened to our tern colonies this year illustrates clearly their vulnerability to weather and extreme events during breeding season as well as showing just how regional variations in weather conditions come in to play.

“We will see more movement of species as the climate envelope moves north.  Animals will move to find the food and temperatures they need for their survival.  We have seen this behaviour particularly from moths and butterflies over the past few years and in future are likely to see more species ‘moving in’ from the continent.

“We can’t ‘undo’ the changes to wildlife we are already seeing at our places but we can do everything we can to nurture nature.”

For more information on the National Trust’s conservation work or to donate to their Everyone Needs Nature appeal, please visit www.nationaltrust.org.uk

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