Tag: UK Centre for Ecology & Hydrology

Concern for seabird colonies despite bird flu breeding recovery

New study examines how the HPAI epidemic affected local seabird colonies

Seabirds that survived recent bird flu outbreaks have continued to reproduce, although overall breeding performance remains notably low, according to a new study.

The paper, led by Edinburgh Napier University’s Dr Sue Lewis, in a collaboration with conservation scientists and staff from the RSPB, the Scottish Seabird Centre and the UK Centre for Ecology & Hydrology has been published by the international avian science journal Ibis.

They studied breeding success in Northern Gannets at the Bass Rock in Scotland and Bempton Cliffs in England during 2023.

Bird flu had a devastating effect on seabirds across Europe and North America between 2021-2023, with gannets, known for their spectacular plunge dives, among the hardest hit. Outbreaks of highly pathogenic avian influenza (HPAI) occurred at all but one gannet colony across their North Atlantic range in 2022, causing mass mortalities on an unprecedented scale.

For this study, scientists compared the breeding success of birds with black eyes – a striking side-effect of an HPAI infection – and those with normal, pale blue eyes.

Overall, they found that breeding success of birds with black eyes did not differ from birds with blue, suggesting that gannets who survived HPAI infection were able to raise chicks just as effectively as those that showed no sign of a past infection.

Breeding success across both groups in 2023, however, was still markedly lower than long-term records – with nest failure rates almost doubling.

At the Bass Rock – which was home to the world’s largest colony of the species before the epidemic – pairs fledged an average of just 0.56 chicks, compared to 0.78 in the 1960s. Meanwhile at Bempton Cliffs, success averaged 0.62 chicks per pair, down from a pre-epidemic mean of 0.81 between 2009 and 2021.

A black-eyed gannet with a chick. Picture credit: Amy King

The authors of the paper believe the dip could be down to birds having to form new partnerships after the death of their long-term partner and less experienced breeders making up a larger share of the population, in combination with a density of nests after mass mortality. The summer heatwave of 2023 may also have played a role.

The findings highlight the complex consequences of disease outbreaks in wild populations, showing that even when survivors appear healthy, impacts to the wider ecosystem can persist.

Lead researcher Dr Sue Lewis, from ENU’s Centre for Conservation and Restoration Science, said: “While it is reassuring that gannets that recovered from avian flu are able to breed, the overall reduction in breeding success is a serious concern.

“The results suggest that population recovery may be slower than hoped, even if survivors are still able to breed.

“Survivors are breeding as well as their peers, proving that gannets are remarkably resilient birds. But with bird flu still circulating and climate extremes adding new pressures, continued vigilance is needed to ensure that these majestic plunge diving birds remain part of our coastal environment for generations to come.”

Dr Jude Lane, from RSPB’s Centre for Conservation Science said: “HPAI has had a devastating impact on many of our seabird populations, which are already facing increasing threats from development and climate change.

“Long-term monitoring will be key to tracking their recovery and understanding whether HPAI infections have hidden effects on survival or behaviour.

“However, it is essential we also take steps to secure long-term resilience for seabirds, such as protecting feeding grounds and reducing bycatch.”

Gannets diving at the Bass Rock. Picture credit: James Glossop

Emily Burton, Senior Conservation Officer with the Scottish Seabird Centre Conservation Team, said: “Black-eyed gannets are now a common sight on Bass Rock, serving as a reminder of the devastation that was caused by bird flu.

“It’s reassuring that this research has found that these survivors are breeding just as successfully as other gannets.

“However, the slow rate of recovery is deeply concerning, particularly when considered alongside the growing threat to seabirds from climate change and poorly sited offshore windfarms.

“Further action is urgently needed from the Scottish and UK Governments to ensure these special birds are protected, their populations can recover, and their future is secured.”

UK’s Butterfly Winners and Losers of 2023 Revealed

The latest results from the annual UK Butterfly Monitoring Scheme (UKBMS), led by wildlife charity Butterfly Conservation, the UK Centre for Ecology & Hydrology (UKCEH), British Trust for Ornithology (BTO) and the Joint Nature Conservation Committee (JNCC), show that 2023 was a mixed picture for butterflies, with some species soaring while others continued worrying declines.

Half the 58 species had a better than average year while the other half were below average at monitored sites. Species that flourished included Chequered Skipper, Brimstone, and Large Blue, which all recorded their best year since the UKBMS began in 1976. 

Another species recording its best-ever year was the Red Admiral, a migratory species that has begun to overwinter in the UK as the climate has warmed, making it a common visitor across all habitats, including gardens. Its numbers have increased by 318% at monitored sites since 1976.

At the other end of the scale were the Small Pearl-bordered Fritillary and garden favourite the Small Tortoiseshell, recording their lowest numbers in the 48 years of monitoring, declining by 71% and 82%, respectively since 1976.

Small Tortoiseshell had its worst year on record in England, second worst in Wales and joint fifth worst in Scotland in 2023, but did really well in Northern Ireland, logging its second best year.

The Large Blue, which was reintroduced to the UK after becoming extinct in the 1970s, recorded its best year yet, showing the conservation work with this species is really working. 

Other species that had a remarkable year include Brown Argus, Marbled White, Comma, Black Hairstreak, and Holly Blue, which all ranked in their top three best years since 1976. On the other hand, Cryptic Wood White, Grizzled Skipper, Pearl-bordered Fritillary, Grayling and Scotch Argus faced significant difficulties. 

The Green-veined White and Ringlet both had a poor year, perhaps suffering ongoing effects from the drought the previous summer. 

The UKBMS, which began in 1976, is one of the world’s longest-running insect monitoring schemes. 

Dr Richard Fox, Head of Science at Butterfly Conservation, said: “Butterfly numbers fluctuate naturally from year to year, largely due to the weather, but the long-term trends of UK butterflies are mainly driven by human activity, including habitat damage and destruction, pesticide use, pollution and climate change.

“By monitoring long-term butterfly trends we can learn about the impact of climate change and other factors on our native wildlife.” 

Dr Marc Botham, Butterfly Ecologist at the UK Centre for Ecology & Hydrology, added: “Butterflies are an indicator species, meaning they can tell us about the health of the wider environment, which makes the UKBMS data invaluable in assessing the health of our countryside and natural world in general.

” The mixed results this year emphasise the need for continued monitoring and conservation efforts to protect these important species and their habitats.”

Dr James Heywood, Breeding Bird Survey National Organiser at the British Trust for Ornithology, whose volunteers contribute to the UKBMS, commented: “In 2023, thousands of skilled volunteers monitored a record-breaking 3,316 sites across the UK, gathering valuable data that will help to inform conservation decisions for the future.

“We are incredibly grateful to each and every one of those people who carry out the monitoring and help us to maintain this highly valuable study.”

Chris Tuckett, Chief Officer for Strategy and Impact at JNCC, said: “The evidence produced through environmental monitoring, such as the UK Butterfly Monitoring Scheme demonstrates the vital role these schemes play in helping us understand the effects of pressures on the natural environment and, equally importantly, how efforts to address these pressures through nature conservation and recovery can be effective in reversing decline. 

“JNCC has supported these schemes, which involve thousands of dedicated volunteers, for over 30 years, and remains committed to continuing to support them in the future.”

The UKBMS now records data on over 3,000 sites per year and the resulting dataset is a crucial resource for understanding changes in insect populations and has provided significant insights into almost all aspects of butterfly ecology. 

As the UK faces the ongoing challenges posed by climate change and other environmental pressures, the work of the UKBMS and organisations like Butterfly Conservation, the UK Centre for Ecology & Hydrology, the British Trust for Ornithology and JNCC remains essential in monitoring and protecting precious butterfly populations and the habitats they depend on.

Public urged to hunt for woodland moths

MOTH NIGHT 19th – 21st MAY

Moth enthusiasts, conservationists and the public will be heading for the woods for the UK’s annual Moth Night event this week. Running on the days and nights of Thursday 19th – Saturday 21st May, this annual celebration of moths is organised by Atropos, Butterfly Conservation, and the UK Centre for Ecology & Hydrology (UKCEH).

Moth Night highlights the important role played by the 2,500 species of UK moths, unsung heroes of our native wildlife both as plant pollinators and essential food for many other animals.

Woodland, the theme of this year’s event, is a vital habitat for moths because their caterpillars feed on trees, shrubs and lichens, while woodland flowers provide nectar for adult moths. Woodland also provides relatively warm, sheltered conditions, ideal for a wide variety of springtime moths to fly in.

Mark Tunmore, editor of the journal Atropos and Moth Night founder, says: “Common broad-leaved trees such as birches, oaks and willows support hundreds of different moth species here in the UK, which in turn are a vital link in the food chain, particularly for bats and insectivorous birds.

“Great Tits and Blue Tits, for example, depend entirely on moth caterpillars as food for their chicks. At this time of year, woodlands are at their colourful best and so are their moth inhabitants, with a wide range of beautiful species on the wing.

“We are also encouraging daytime moth hunts this year as there are many day-flying species to be seen, including the stunning Broad-bordered Bee Hawk-moth, Speckled Yellow and Argent & Sable. In Scotland it is a particularly special time of the year for moths, with scarce species such as the spectacular Kentish Glory, Netted Mountain Moth and Small Dark Yellow Underwing flying.”

The abundance of moths has declined by one-third in Britain over the last 50 years and a recent study suggested that declines had been even more extreme in more wooded landscapes. However, some woodland moths have done well, benefitting from the increase in broadleaf woodland in the UK, which has more than doubled in area since the late 1960s.

Dr Richard Fox, Head of Science at the charity Butterfly Conservation, says: “Government commitments to increase tree cover are very welcome. Allowing natural regeneration of woodland and more tree planting will greatly benefit moths as well as helping to tackle the climate crisis.

“However, it needs to be the right trees in the right places. Planting non-native trees, such as conifers or Eucalyptus, or planting trees on wildlife-rich open habitats such as grasslands and heaths, will have a negative impact on biodiversity, including for moths.

“In addition, we need to redouble the protection of the UK’s remaining ancient woodlands; unique, irreplaceable habitats of great wildlife, and also historical and recreational, value. At this time of year, our ancient woodland feature moths such as the nationally scarce Marbled Pug, Barred Umber and Marbled Brown.”

Dr David Roy, Head of the Biological Records Centre at UKCEH, says: “For Moth Night 2022 we’re encouraging the public to look for and submit sightings of moths in woodland, but also in their gardens, parks and the wider countryside.

“There are public events that people can attend to see magnificent moths. Moths are excellent indicators of biodiversity and the quality of woodland and other habitats, so by submitting Moth Night sightings, people are doing citizen science and helping understand the impacts of land management and climate change.”

For more information on taking part in Moth Night, which runs 19-21 May 2022, see:  www.mothnight.info

How to take part in Moth Night 2022

While you can buy light-traps that do not harm the insects, specialist equipment is not required to attract moths. Leaving outside lights on, painting ‘sugar’ mixture on fence posts, or draping rope soaked in red wine over bushes can be particularly effective. 

There is advice at mothnight.info/taking-part/

For help identifying moths, people can check guides to species, the What’s Flying Tonight? app or contact moth enthusiasts via the Moth Night Facebook page.