As the climate shifts, new visitors are winging their way north

With its varied landscape of beaches, hills, lochs, marshes and sandy beaches, the island of Mull is a wildlife haven and home to some of the most delightful and impressive birds.

For those with a keen eye, soaring above the hundreds of miles of rugged coastline can be seen golden eagles, white-tailed eagles, peregrine falcon and sparrow hawk. By waters’ edges are nesting kittiwakes, fulmars and black guillemot, while countless ducks, geese, and waders are a common sight.

As of this week, Mull’s impressive list of bird species has a new, rare addition; one that, thanks to our changing climate, may well be a portent of what lies ahead. Walking tour guide Theo de Clermont was beside Loch a’Chumhainn near the picturesque village of Dervaig when, low over the estuary, erupted a flurry of activity among the gulls and waders.

Black kites, which use their five feet wing spans to effortlessly glide as they scan for rodents, birds and fish which they grab using their long talons, are widely found in places as far flung as Australia, India and southern Europe. In recent years, numbers in France have crept up.

But the Isle of Mull on a Monday evening in May is far from where one might be expected to turn up.

“It was a bit of a bucket list moment to see it,” recalls Theo, who works as a naturalist with NatureScot and has only been on the island for six weeks.

“It was probably blown up on southerly winds all the way up here, but it could be a sign of things to come.”

The sighting is a first for the Isle of Mull and only the fifth time a black kite – more dark brown in colour than the name suggests – has been spotted in Argyll. While within days came another black kite sighting, this time in Unst, Shetland.

According to research from the British Trust for Ornithology (BTO), black kites are one of a more than a dozen birds expected to colonise the UK as a result of warming temperatures.

And while the Mull bird is regarded as one-off stray blown to the island by accident, it’s only a matter of time, say experts, before breeding pairs become a more common sight at spots around the UK.

Paul Walton, of bird charity RSPB, said: “Black kites were an extreme rarity in the UK a few decades ago and have become more regular visitors over the past 10 years, with around 20-30 recorded annually.

“The Mull bird is part of that trend – an exciting find for birdwatchers.

“Colonisation as a breeding species is possible in coming years,” he adds. “The breeding ranges of species do change over time – at the moment more often shrinking than expanding, but some range expansions are being recorded and the black kite is one.

“This could be helped by climate change, as the preferred ‘climate envelope’ of some southern species expands to higher latitudes – it is hard to be certain, however.”

As well as black kite, a range of other winged species are expected to become a familiar sight as the temperature shifts.

Colourful hoopoes and bee eaters found in Europe, Africa and parts of Asia, are predicted to eventually become well established, while the glossy ibis, an exotic bird normally found in the Mediterranean is expected to start breeding in the UK this year due to the warming climate.

Distant relatives of storks and herons, they have been encouraged to migrate north due to extremely dry conditions in the south of Spain and Portugal. There have been random sightings in recent years in South Uist, Eigg and Mersehead nature reserve near Dalbeattie.

In the past decade more than 55 land-based and marine species have moved to parts of Britain outside their natural range, including purple herons which are now established in Kent, and European bee eaters, which first bred in the UK in 2014.

Night heron, little bittern, cattle egret and great white egret have also made the UK their home, raising the stakes that they will eventually arrive in Scotland.

According to the BTO, black kite, short-toed treecreeper – a small speckled bird with long curved beak being spotted in the south of England – and Bonelli’s Warbler, a petite woodland bird which has stretched into the north of France, are also predicted to be on the way.

“The nuthatch which was virtually unknown in Scotland 30 years ago is now a very regular breeder and still spreading north,” added Mr Walton.

“We have little egrets colonising England and we can expect then eventually to establish in Scotland, perhaps alongside other birds such as avocet great white egret.”

While it may excite twitchers, the shifting species raise concerns for the impact of climate changes on much-loved and familiar species, both as a result of the rising temperatures forcing native species to seek cooler climes, and the impact of new arrivals on food and territories.

In a report published to coincide with COP26, the BTO warned the UK’s puffin population could plunge by up to 90% by 2050 if global warming is not halted – a loss of more than one million birds.

Kittiwake, Arctic tern, Arctic skua, and fulmar, are among the three quarters of UK seabird species said to be at risk as sea temperatures rise, disrupting food chains.

And it’s not only birds that are winging their way northwards. The British Dragonfly Society says six new species of dragonflies and damselflies have arrived in Britain since the late 1990s, while a seventh has returned after being wiped out in the 1950s.

Its annual State of Dragonflies report, released last autumn, says of the 56 different dragonfly and damselfly species found across the UK and Ireland, 19 have seen “significant increases” in their population size since 1996.

On the other hand, five others have “significantly declined”, with the potential for more damaging climate impacts in the future.

Brian Walker, BDS Chairman, said: “New species and range expansions sounds like good news for dragonflies, but the speed at which new species are arriving and colonising should actually be taken as further warning about the danger of rapidly changing climate conditions.

“The evidence suggests that species favouring cooler conditions are contracting their range and certain habitats such as bogs are drying out and this is having an adverse effect on the species which rely on them.”

Among the new arrivals are the small red-eyed damselfly, first seen in the south of England in 1999 and which has already reached County Durham, and the willow emerald damselfly. It began colonising the UK in 2007 and is said to be moving north at a rate of around 15 to 20 kilometres per year.

Among the losers are the emerald damselfly, which favours shallow ponds and bogs which dry up earlier as the weather warms, and the black darter, typically found in acidic bogs, pools and lochs and widespread in the Highlands, which has declined by 12%.

Meanwhile, perhaps the strongest sign that our skies are changing comes from the BTO, which recently confirmed that swallows – whose arrival from South Africa typically herald the start of spring – have started spending the winter in parts of the south of Britain and Ireland.

“We haven’t got to go back too far to remember winters when it would have been impossible for swallows to survive the freezing temperatures,” said BTO’s chief executive Juliet Vickery.

“But as our winters get milder, it is something we may see more and more.”

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