From Rare Bird Alert

A new report published this month has highlighted the threat marine plastic pollution poses to seabirds in the north-eastern Atlantic region. Researchers found that, of 34 seabird species investigated, 74% had ingested plastic.

The authors of the new study, from the North Highland College UHI’s Environmental Research Institute, part of the University of the Highland and Islands, and the RSPB Centre for Conservation Science collated data from all known studies reporting instances of plastic ingestion and nest incorporation in seabirds around northern Europe, Scandinavia, Russia, Greenland, Svalbard, the Faroes and Iceland.

Dr Nina O’Hanlon, of Environmental Research Institute, explains: “Marine plastic pollution is an increasing and global environmental issue which poses a major threat to marine biodiversity. The production of plastic continues to rise with millions of tons entering the oceans each year. Seabirds can ingest plastic, become entangled in it or incorporate it into their nests, causing impacts which may have negative consequences on reproduction and survival.”

Dr Alex Bond, RSPB senior conservation scientist, said: “The north-eastern Atlantic Ocean is home to internationally important breeding populations of seabirds and an amazing array of other marine life. Solutions to plastic pollution in the oceans require concerted action at its source on land – 80% of marine litter is thought to come from land – especially by producers and users.

“The properties which make plastics desirable are the very things which make it problematic,” Dr Bond continues. “Due to its low cost, approximately half of all plastic items are produced for single-use. Plastic never breaks down, it only breaks up, into smaller fragments which remain in the environment and, as its density varies, it can be found throughout the water column, increasing the number of species which come into contact with it.”

While the team’s research highlights some concerning statistics, its report concludes that more coordinated, comprehensive and detailed investigations are required on plastic ingestion and nest incorporation to assess the full impact marine plastic is having on seabird populations.

Dr O’Hanlon explains: “In the north-eastern Atlantic Ocean, an area of international importance for seabirds, there has been little effort to better understand how marine plastic affects different seabird species over time and regionally. We actually know very little about the current prevalence of plastic ingestion and nest incorporation for many species, several, like the long-tailed duck and Atlantic puffin, which are globally threatened. Only 49% of the 69 species which are commonly found in the region have been investigated for plastic ingestion. We believe it’s vital to have a multi-jurisdictional, coordinated and collaborative effort to gain a more comprehensive and current understanding of this important issue.”

The group’s research was undertaken as part of Circular Ocean, a project funded by the EU’s Northern Periphery and Arctic Programme, which aims to incentivise the reuse and recycling of marine plastic litter in remote and rural regions.

The full paper Seabirds and marine plastic debris in the northeastern Atlantic: A synthesis and recommendations for monitoring and research can be read here

From Rare Bird Alert

Calling European storm petrels have been recorded for the very first time on the Shiant Isles, Scotland this summer, an important milestone for the Shiant Isles Recovery Project, which is working to attract these small seabirds to nest on the islands. The characteristic “churring” call of storm petrels was heard from burrows, their breeding habitat, an encouraging sign that the project’s conservation work is paying off.

The EU LIFE+ funded partnership project between RSPB Scotland, Scottish Natural Heritage, and the Nicolson family, the custodians of the islands, began in 2014 to provide safe breeding grounds for Scotland’s globally threatened seabirds on this cluster of islands in the Minch, five miles off the coast of Harris. A population of invasive non-native black rats on the islands were thought to be limiting the breeding success of the colonies of puffins, razorbills and guillemots, whilst storm petrels and Manx shearwaters were not found there at all.

Following a rat eradication programme in the winter of 2015/16 the project has been focused on monitoring how the wildlife has responded, ensuring the biosecurity of the islands, and attempting to attract storm petrels and Manx shearwaters to breed, as there is ideal nesting habitat for them. It will be March 2018 before the islands can be officially declared free of rats, provided none are found between then and now.

Storm petrels are little bigger than sparrows and only come to shore in summer to breed. Scotland’s internationally important population currently only nests at a limited number of potentially available sites on offshore islands because of their vulnerability to predation. They are known to abandon and avoid nesting sites where rats or other ground based predators are found.

While these small seabirds have been recorded flying past the Shiants for many years by the Shiants Auk Ringing Group prior to the recovery project beginning there was no evidence that they were landing on the islands or attempting to nest there. Last summer night vision cameras captured footage of several of these small seabirds, but this is the first year their churring has been heard in burrows.

This summer a speaker broadcasting a recording of a storm petrel churring (hear storm petrels here) was placed by some boulder scree near the shore and played throughout the night. The project hoped that this would not only attract storm petrels to the area so they could discover the nesting sites, but also to settle and start a breeding colony there. Calls from birds were recorded from three separate sites close to the speaker.

A night vision camera also captured footage of a storm petrel displaying nesting behaviour; looking relaxed and heading into a burrow. While it’s possible that birds may have successfully bred on the islands this summer confirming this is difficult due to them only entering and leaving their nest burrows in darkness and would have risked disturbing them due to the locations of the calls.

Dr Charlie Main, Senior Project Manager for the Shiant Isles Recovery Project said: “The churring of a storm petrel is very distinctive and we’re delighted that it’s been recorded on the Shiants this summer. While we are still some way off the islands being officially declared rat free these calls indicate that all the biosecurity work we’re doing to keep these islands predator free and make them ideal breeding sites for seabirds is paying off.

“It’s even more exciting to think that the birds may have bred on the islands this year, although the risk of disturbing nesting birds meant we were unable to confirm this. These calls are very positive signs for the future and we hope that next year we’ll be able to record even more calls and footage of the birds. The long term aim is to allow a breeding colony of storm petrels to establish at the Shiants.”

Dr Andrew Douse, Policy & Advice Manager, Ornithology at Scottish Natural Heritage said: “The return of storm petrels as a breeding species on the Shiants is one of the key aims of the project for SNH, so the news of birds recorded calling is very welcome. Storm petrels only occur on islands without rats, which means that they are very vulnerable to the effects that arise from invasive species such as these. The Shiants are an ideal breeding location for storm petrels and hopefully they will go on to become an important stronghold for this species.”

In the Channel Islands we have a healthy population of storm petrels on (rat-free) Burhou (Alderney) but the presence of rats elsewhere, even in otherwise suitable areas of the coast like Plémont, mean that we have nowhere near as many as we could have in the islands with adequate management.

From Carbon Brief

Flying back too early or too late for spring is costly for migratory birds. Their arrival must coincide with the emergence of food sources, such as caterpillars, in order to enable them to feed and successfully rear their young.

Birds that overwinter in warmer climes, including willow warbler, tree pipit and barn swallow, will be unable to cut their migrations short as climate change causes spring to arrive earlier in many parts of Europe, as new evidence suggests that some birds are much less adaptable to climate change than previously hoped.

Time to fly

Each winter, around half of the UK’s birds take off to find food in a more temperate climate, returning to their ancestral breeding grounds the following spring. However, scientists fear that this annual migration could be disrupted by climate change, which is causing spring to arrive six-to-eight days earlier in Europe than it did 30 years ago.

Evidence suggests that some birds will be able to adapt by leaving for their winter grounds later in the year or wintering closer to home (see BOTE report here). However, not all birds are able to perceive subtle shifts in temperature and instead rely on the number of daylight hours – which is unaffected by warming – to tell them when it’s time to fly.

For these birds, keeping pace with an earlier spring means getting back from their wintering grounds more quickly. But the solution isn’t as simple as flying at a faster speed because birds simply do not have the energy to beat their wings any harder during their lengthy migrations. A new study, published in Nature Climate Change, looks at a third option: reducing the length of “stopovers”. These are the avian version of a pit stop, where birds feed and rest before continuing their journey. While shorter stopovers can significantly speed up a migration, it’s unlikely to be enough, the study finds.

For example, cutting time spent resting by 50% would lead to birds arriving in their spring grounds just two days earlier, on average. In comparison, the peak availability of caterpillars – a key source of food for birds – in UK forests advanced by 20 days between 1980 and 2008. This mismatch between the arrival time of birds and their foods could spell trouble for many bird species that are unable to adjust the start of their spring migration, says lead author Dr Heiko Schmaljohann from the Institute of Avian Research in Germany:

“The inability to sufficiently adjust or adapt the breeding area arrival timing leads to an increasing mismatch between food availability and its demand. If this mismatch increases for a species population, it is possible that this may lead to a population decline.”

Schmaljohann adds that although there are some birds which seem to be adjusting their spring arrival date in response to climate change, such as the pied flycatcher, it is still not known which species are most at risk of decline:

“The pied flycatcher has advanced its breeding area arrival timing the most. Whether they have a better ability of detecting how conditions will be at the breeding area in one to two months is totally unknown. It is extremely unlikely that birds, being still at their African wintering grounds, can anticipate the environmental conditions they will experience at the breeding areas in advance.”

Calculating migration speed

To understand what drives the speed of a migration, the researchers reviewed data from 49 tracking studies of 46 different bird species.

They found that the overall migration speed is largely dependent on the number of stopovers, which they defined as spending more than one day in the same location. Researchers then used mathematical modelling to predict how reducing the amount of time resting while flying home could help birds to speed up.

Their modelling considered the average flying speed, the total migration distance and how birds can vary their speed in response to changing environmental conditions. In the future, birds may actually be forced to take longer breaks as their stopover grounds will likely be affected by climate change, says Dr Schmaljohann:

“When birds experience unfavourable conditions, such as drought, heavy rain and cold temperatures, the feeding conditions deteriorate. The feeding conditions directly affect total speed of migration via stopover duration.”

Adapting on the fly

This new research may help to explain why birds appear increasingly unable to keep pace with climate change, says Dr Stephen Mayor, an ecologist from the University of Florida, who wasn’t involved in the study:

“You would think that birds which migrate thousands of kilometres with the changing seasons would be experts at adapting to climate change, but this evidence suggests birds are much less adaptable than we might hope – probably because the climatic changes are so rapid and variable.”

The full paper The limits of modifying migration speed to adjust to climate change, Nature Climate Change can be seen here

We worry about our puffins. We worry a lot and not without good cause. Our puffins have probably been in trouble since humans and their hangers on, the rats, dogs, cats and ferrets that follow them, first turned up in Jersey. Or walked along the peninsula presumably. And it’s not like the puffins could have been totally casual in their choices of nest sites before arrival of humans – wolves, foxes, stoats and weasels didn’t need us to show them where the seabirds were. Picking places to breed where wolves can’t get to is probably a lot easier than choosing rat-free ones. It’s a surprise that the burrow-nesting puffin even made it this far – nowhere else will they nest where rats are even vaguely close by.

Unfortunately our actual records of puffins in Jersey are pretty poor. Everyone “knows” there were once lots although no one ever actually counted them. Or looked in their nest burrows. Or even it seems, really, confirmed that they actually bred here at all – puffin chicks are reared underground and, abandoned by their parents, leave the burrow alone and at night. They fly straight out to sea and away, never really ever seeing their parents as it was dark in the nest where they grew up. It’s perhaps no surprise then that we never see the little ones, the pufflings, either.

That Jersey’s puffins, like those in France have gone down numbers further in recent years is quite clear and, in 2015, Kaja Heising even wondered if the puffin’s time in Jersey was finally up. That the bird of many a local t-shirt, souvenir and local television show would be lost for ever. I further suggested that in Jersey we risked emulating Mauritius’s relationship with the dodo – an island using an extinct bird as an icon.

Jersey’s puffins are pretty well the most southerly of their kind in the world. The one colony below us, Rouzic in Brittany, has itself suffered. Not least in their case as gannets have moved into their neighbourhood and taken over. Interestingly it’s possible that puffins don’t really get kicked out by gannets but that all that burrowing will eventually remove the topsoil they need, making it useless for puffins but lovely for gannets (like they did on the Welsh island of Grassholm). The puffin may be rare amongst nature in that it, like us, can completely destroy the home it needs most.

The southern-most puffins are also finding the seas around them getting warmer as the climate changes. British waters, already grossly overfished, are now seeing new fish species that were once rare this far north (witness the change of moulting sites of the Balearic shearwater), fish not all to the liking of puffins, particularly not for the pufflings.

So, what of our puffins? Have they finally gone from Jersey? Well, that’s the thing, they’re still here. Not many but where there’s hope etc. This year there are eight pairs it seems, and everything suggests that they are at least trying to nest and breed successfully. Of course, our puffins can’t burrow into the soil as they’d like to as the rats would get them, so they pick inaccessible cracks in the rock that they can fly into. Local ecologist Piers Sangan and top birder, Mick Dryden, are watching the puffins like no one has done before in Jersey, mapping them and trying to understand their behaviour while in our waters. Piers reports both members of one pair flying into one rock crevice carrying fish – to feed an unseen baby? That sounds like a probable breeding to me – our first record at last?

And what of the threats, do we know more about these? We know that our birds are unlikely to access somewhere to burrow thanks to the attentions of unwanted mammals. But how bad is this and how many of the pesky mammals are there on the cliff tops? Invasive mammals expert Kirsty Swinnerton is planning to find out and think up ways perhaps of getting rid of them. Or at least keeping them safely away from the birds. Local expert, and chough monitor, Keith Pyman has also wondered whether our fulmars, which colonised Jersey in the 1970s, might not be blame-free too. At least in not helping the precarious position of our puffins.

Fulmars are never normally any threat to nesting puffins but these petrels, who can spit some pretty foul stomach contents at anyone annoying them, probably don’t normally get that close to burrowing puffins. However, here in Jersey, fulmars nest on the ledges and mouths of cracks and crevices – do they block the puffins’ nests? Puffins find it hard enough to approach their Jersey homes anyway (puffins in big grassy colonies simply throw themselves into the ground and run to the burrow) those using small rock crevices find the precision approach difficult without the threat of the spitting fulmar. Keith has noted fulmars in the places where in years past he saw puffins disappearing underground.

Our puffins are still hanging on and you can see the sightings on the Jersey Birds website along with updates on our small number of razorbills, some over-summering guillemots and, somewhat weirdly, the fine black guillemot enjoying our summer with its (reluctant?) razorbill friends. As noted above, where there’s hope there’s a way, so let’s give our puffins some support. With a better understanding of the numbers and locations of all our birds and the true level of threats that they face we may be able to devise some strategies to stop the puffin’s disappearance, ways that might need everyone to remember just how much they love puffins.

The UK Government has released a report assessing bird populations across the UK between 1970 and 2015 particularly in selected and vulnerable groups: farmland, woodland, water and seabirds

Why should governments monitor bird populations?

Bird populations have long been considered to provide a good indication of the broad state of wildlife in the UK. This is because they occupy a wide range of habitats and respond to environmental pressures that also operate on other groups of wildlife. In addition, there are considerable long-term data on trends in bird populations, allowing for comparison between short term and long term. Because they are a well-studied taxonomic group, drivers of change for birds are better understood than for other species groups, which enables better interpretation of any observed changes. Birds also have huge cultural importance and are highly valued as a part of the UK’s natural environment by the general public. However, the bird indicators presented in this publication are not intended, in isolation, as indicators of the health of the natural environment more widely. It is not possible to determine changes in the actual number of birds for each species in the UK each year, it is possible to estimate the relative change, from counts on sample plots surveyed as part of a range of national monitoring schemes just as Birds On The Edge and others do in Jersey.

Trends in bird populations are used by policy makers, government agencies and nongovernmental organisations as part of the evidence base to assess the effects of environmental management, such as agricultural practices, on bird populations. The trends are also used to assess the effectiveness of environmental interventions intended to address declines, such as agri-environment schemes targeted at farmland birds.

Understanding the bird population indices

Individual bird species population trends, based on expert surveys, are calculated as an index. This relates the population in a given year to a ‘baseline’ – the first year that data are available – which is given a value of 100. Thereafter, the index is expressing the population as a percentage of this ‘baseline’.

This annual Defra National Statistics Release presents data trends up to 2015 in populations of common birds (species with a population of at least 500 breeding pairs) that are native to, and breed in, the UK, with trends overall and for four main habitat groups (see Annex A in the report for a list of birds in each group). The release also presents trends for wintering waterbirds, some of which also breed in the UK. The charts presented combine individual species indices into a single indicator to provide an overall trend for each group mentioned above. The indices are considered to give reliable medium to long-term trends but strong reliance should not be attached to short term changes from year to year.

Assessing the trends

Two trends are referred to in the text: the unsmoothed indices show year-to-year fluctuation in populations, reflecting the observed changes in the survey results; and smoothed trends, which are used to formally assess the statistical significance of change over time. Smoothed trends are used for both long and short term assessments as they reduce the short-term peaks and troughs resulting from, for example, year to year weather and sampling variations. The most recent year of data, i.e. 2015 in this update, is likely to change due to the smoothing process following the inclusion of 2016 data in next year’s update. As a result it is not appropriate to make assessments based on this figure. Where results from the smoothed indices are quoted, this is clearly indicated.

Executive summary

The combined all species index has changed little compared with 40 years ago in the UK, however, this masks considerable flux, with some species increasing and some species decreasing in population size. These changes in relative abundance tend to cancel each other out in the combined index.

In 2015:

• The all-species index in the UK was 2% below its 1970 value
• There were less than half the number of farmland birds than in 1970, most of this decline occurred between the late seventies and early eighties
• There were 18% less woodland birds than in 1970
• Water and wetland bird numbers were 7% lower than in 1975
• There were 22% less seabirds compared to 1986
• The number of wintering waterbirds was 88% higher than in 1975-76, the index peaked in 2001 and has declined since.

Between 2009 and 2014:

• The smoothed all species index remained level
• Farmland birds smoothed index decreased 8%
• The number of woodland birds did not change significantly, although the unsmoothed index dipped to the lowest figure ever recorded in 2013 before recovering
• The smoothed water and wetland bird index declined by 7%
• The number of seabirds declined 6%, in 2013 numbers dipped to the lowest ever but have since increased slightly
• The smoothed wintering water bird index fell 8%.

Download the report Wild bird populations in the UK, 1970-2015 here

From BTO

The main theme of The State of the UK’s Birds report (SUKB) 2016 is the latest Birds of Conservation Concern 4 list – BoCC4 published in 2015 (read and download here) – and the species whose status has changed. The increase in the UK’s Red list by 15 species is due to problems in all habitats including farmland, woodland and coasts but most notably in uplands with five new upland species moving onto the red list. One of these is curlew. The UK supports 27% of the global population, and the long-term trend shows a 64% decline from 1970 to 2014. This, combined with the bird’s global status of Near Threatened, suggests that the curlew is one of the most pressing bird conservation priorities in the UK (read more about the curlew here).

“The BTO is working with others on a programme of research to understand the causes of curlew decline and guide potential management solutions. This involves analyses of long-term data collected by thousands of volunteers, using novel tracking technology to study the needs of individual birds, and working with local enthusiasts to inform the recovery of local populations” 
– James Pearce-Higgins, Director of Science, BTO

Upland birds

Whinchat, another largely upland species monitored by the UK and Channel Islands BBS Survey shows a 53% decline during the last two decades.  As an Afro-Palearctic migrant, this species is part of another group for which there is particular concern. Threats and pressures during migration and on the wintering grounds need to be considered alongside the impact of changes in upland habitats in the UK.

More unexpected perhaps, is that grey wagtail has moved from the Amber list to the Red list. Alongside declines in common sandpiper and dipper, this raises wider concerns about species associated with upland streams and rivers. The other two upland species to show marked declines are merlin and dotterel, the latter a montane species likely to affected negatively by climate change and grazing pressure.

Scarce and rare breeding species

As well as the annual update of changes in widespread breeding species based mainly on the BBS, SUKB 2016 once again includes a summary of trends in scarce and rare breeding species, drawn mainly from the annual reports of the Rare Breeding Bird Panel (RBBP) and the SCARABBS programme of periodic surveys.

Of the 91 species reported on in the most recent RBBP report covering 2014, 71 were assessed by BoCC4. Eight species showed an improvement in status (including woodlark, bearded tit and chough, which joined the Green list), with conservation action to maintain suitable reed beds helping the populations of species such as bittern recover. Five species, common pochard, Slavonian grebe, merlin, dotterel and black redstart moved onto the Red list. The remaining 20 of the 91, not assessed by BoCC4, are those which are not considered to be a regular component of the UK’s avifauna. This may be because they breed only occasionally (e.g. European bee-eater), or indeed have never bred, but from time-to-time visiting individuals exhibit breeding behaviour (e.g. great reed warbler). The RBBP logs such occurrences, as it may be that they represent a precursor to future colonisation, such as the first little egrets that displayed to each other in the early 1990s, before first breeding in 1996 and the subsequent population explosion.

The importance of volunteer data

Thousands of dedicated volunteers contributed to the data used throughout most of this report. Data used to calculate UK population trends and related research. Over 2,600 volunteers participated in the Breeding Bird Survey in 2016 alone, one of many surveys highlighted in the report. This particular survey provides annual population trends for 111 species, including upland species such as curlew, whinchat and grey wagtail.

At a smaller, but equally as important scale, the 258 volunteers who contribute to the Waterways Breeding Bird Survey allow monitoring on those species specific to waterways, such as common sandpiper and dipper and cover almost 300 sites annually.

Who produces the report

SUKB is produced by a coalition of three non-governmental organisations (NGOs) – the RSPB, BTO and the WWT – and the UK Government’s statutory nature conservation agencies – Natural Resources Wales (NRW), Natural England (NE), the Department of Agriculture, Environment and Rural Affairs, Northern Ireland (DAERA), Scottish Natural Heritage (SNH) and the Joint Nature Conservation Committee (JNCC).

Download the full report The State of the UK’s Birds 2016 here