Chough report: December 2017

by Liz Corry

As the year drew to a close and daylight hours dwindled to their annual low, the choughs spent more and more time at Sorel close to their roost sites.

Chough movements in December

There was one intriguing public report at the start of December suggesting a new roost site. Farm workers at West Point Farm, St Ouen, had been seeing a pair of choughs in their barns around 7am each morning. At that time of year sunrise occurs around 7.40am. Was the pair roosting in the barns or being ‘the early bird that catches the worm’ and leaving Sorel before everyone else to find food out west?

Choughs leaving the feed site at Sorel. Photo by Liz Corry.

The day of the report, and each day since, there have been 35 choughs at Sorel for the feed. The sun sets not long after with a dozen or so choughs staying at the aviary and the rest heading east, presumably to the quarry.

Taking in the last rays of a December day. Photo by Liz Corry.

Another reason to stay close to Sorel is the supplemetal feed. Now that winter has set in the availability of wild food is low and the need for calories high. December has not been particularly cold – in fact there have been a few balmy days where shorts were an option (for keeper not bird).

An unusually warm day in December enjoyed by the choughs. Photo by Liz Corry.

However, our tiny island has taken a constant battering over the past weeks with gale force winds of 40 to 60 mph. It is bad enough walking or driving in it. Imagine being a 300g bird trying to fly or trying to stay grounded whilst searching for food in the soil.

24 hours later! (note the choughs on the roof) Photo by Liz Corry.

Apart from a demand for more food the choughs have on the whole faired ok so far with the bad weather. They are making the most of the sheep being confined to the aviary field. It is tupping season with one lucky ram confined to two fields with a flock of ewes. Lots of dung with maybe the odd tasty insect morsel inside.

One lucky ram confined to the aviary field at Sorel for tupping season. Photo by Liz Corry.

The choughs have been foraging in amongst the sheep confined to the field adjacent to the aviary. Photo by Liz Corry.

Syngamus strikes again

There have been two cases of syngamus infection this month. Luckily I was able to trap the birds, Lee and Duke, within a couple of days of symptoms showing. They evaded capture on the first day of trying, partly due to the hatches not budging when released (if anyone can come up with a better release hatch design I will pay you! albeit in chocolate coins). The second day their hunger in the increasingly cold wet weather spurred on their motivation for staying inside the aviary and the hatches closed. Much to the relief of the vet on call over Christmas as it was the 23rd December.

Never easy trying to trap choughs who refuse to go inside. Photo by Liz Corry.

Whilst Lee had been our major cause for concern due to gaping and repeated sneezing, it was Duke who sounded the most congested once we had him in the hand. He also had a lot of mucus around his nares which we rarely see.

Duke presented with mucus coming from his nares as a result of infection. Photo by Liz Corry.

Once they had received their wormer injection they were released and left to feed on the pellet and insects at the aviary. Remarkably there have been no observations of sneezing since that day. However, do bear in mind the gales/fog/heavy rain/sleet (often in the same day) have meant that there is little incentive to hang around at Sorel observing birds.

We have tried. Body weights have been obtained for several of the birds. Not consistently to show any trends, but enough to know the choughs getting on the scales are not underweight. These of course will be the more confident individuals and/or ones that have low parasite loads. We have a new type of scale that the birds will use. A lot cheaper than the flat Kern scales (£20 versus £150).

Prototype weighing station using digital kitchen scales. Photo by Liz Corry.

They are not intended as outdoor scales so I have had a few attempts at weather-proofing. The current one needs improving as the birds are unsure. Once they have approved the design plans we can make several weighing stations to place around the aviary ensuring we cater to all of the choughs.

Gianna’s dilemma

Towards the end of November keepers at the zoo started to notice Gianna our foster mum having issues. She was crash landing when flying. Gianna is tame and she lets keepers get extremely close. She lets me open her bill to check for infections or blockages if needed. It was easy to see that the source of Gianna’s mobility problems was her eyes.

Gianna’s left eye was starting to show signs of cataract. Furthermore, there was no reaction in her right eye. She was taken to the Vet Department for further examination. Photos were sent to a UK specialist who confirmed she had cataracts in both eyes.

Jess Maxwell with Head Vet Andrew Routh examining Gianna’s eyes. Photo by Bea Detnon.

Since the initial assessment there has been a noticably downturn in her ability to move around. Understandably as her vision deteriorates her confidence in everyday things like hopping from rock to rock has decreased. She has been moved to an off-show aviary close to the Vet Department so she can receive the best attention from keepers.

Cataract forming in Gianna’s left eye at the start of December. Photo by Liz Corry.

The cataract in Gianna’s left eye by the end of December. Photo by Bea Detnon.

Despite everyone’s love for Gianna we have to accept that her future is murky. There is the option of an operation to remove the cataracts. As you can imagine this is very specialised, expensive, and relies on the individual being strong enough to undergo the operation. For those of you interested in avian ophthalmology click here. If the operation option is not feasible her quality of life will then need to be carefully considered.

Season’s greetings

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From all of us at chough HQ we hope you enjoyed your Christmas holidays and wish you all the best for 2018. Thank you for your continued support.

State of the UK’s Birds 2017

State of the UK's Birds 2017Just published, the latest State of the UK’s Birds Report highlights how our birds are doing. Some of our summer migrants are arriving earlier, the distributions of others are moving north and some are just beginning to colonise. The report is only possible due to the efforts of volunteers who take part in BTO surveys including those throughout the Channel Islands.

Headlines

  • Climate change will provide opportunities for some species, while others will be more vulnerable
  • Birds in the UK are showing changes in abundance and distribution, predominantly moving northwards, in a way that is consistent with a changing climate
  • Migratory birds are arriving earlier and egg-laying dates have advanced such that swallows, for example, are arriving in the UK 15 days earlier, and breeding 11 days earlier, than they did in the 1960s
  • A large number of bird species are likely to have opportunities for colonisation and range expansion in the UK under projected climate change. Potential colonists include a number of wetland species such as little bittern and night heron. A considerable list of southerly-distributed species have already shown substantial increases in recent years, including garganey, quail and little egret

Garganey pair. Photo by Mick Dryden

  • Climate change will increase the pressures on species already in decline. A number of our declining rare breeding birds, including dotterel, whimbrel, common scoter and Slavonian grebe, are likely to be at a higher risk of extinction in the UK, based on projections of how climate will become less suitable for them

Slavonian (horned) grebe. Photo by Mick Dryden

  • The UK’s kittiwake population has declined by 70% since 1986 because of falling breeding success and adult survival. Climate change has reduced the availability of the sandeels they rely upon in the breeding season. Other species that feed largely on sandeels, such as Arctic skua, Arctic tern and puffin, are at high risk of climate-related decline
  • National surveys provided updated population estimates for capercaillie and hen harrier and revealed declines for both species
  • In the UK Overseas Territories, there are positive signs of recovery for four endemic land birds on Henderson Island and updates on a successful translocation project for the cahow.

Download the full report State of the UK’s Birds 2017 here

Kittiwake. Photo by Mick Dryden (3)

Chough report: November 2017

Choughs took flight this month to explore the west coast of Jersey. Photo by Trevor Biddle.

By Liz Corry

Having spent most of November on holiday or in bed overdosing on Lemsip, I thought I would get away with not having to write anything this month. However, as is now tradition, it is times like these when the choughs start hitting the headlines. So, thanks entirely to public sightings, I have the following news to share.

New sightings for November

There have been a couple of positive sightings of choughs at Petit Port and Corbiere once again. We never know every individual involved, but we do get at least one or two positive sightings of choughs in the area each year around this time and this year we have had some positive identification like Roy Filleul’s photo of PP003 at Corbiere and Mary with friend in the NT Field, St Ouen’s Bay.

Staff at Simon Sand & Gravel Ltd had a surprise sighting of two choughs flying around their buildings on 3rd November. They managed to film it and post on their Facebook site, see below. Since then we have been receiving reports of choughs making the most of St Ouen’s Bay. It tends to be 2 to 3 birds at a time, no large groups, and they are seen in the same places (although there could be observer bias in that).

We had a report of a chough drinking from the water’s edge at the St Ouen’s Pond Scrape (in front of the Eddie Buxton hide) which is personally very exciting as I’ve only ever seen them drink from the aviary water tray and the sheep bowsers.

Kempt Tower and Les Mielles nature reserve are becoming popular with at least three of the choughs. Thanks to Trevor Biddle’s photo of them down at the Scrape (south of St Ouen’s Pond) we know the identities of the three explorers; Pyrrho and wild-hatched siblings known to us as PP004 and PP005. Rather interestingly these three have been a trio since the start of this year and observed carrying nesting material towards the quarry back in spring.

Three sub-adult choughs spotted by a member of the public near the Scrape, St Ouen’s Bay. Photo by Trevor Biddle.

It is likely that people are seeing the same three in the area, but without leg ring information this cannot be confirmed. Understandably that information is hard to obtain, it is amazing just to get photos. All this knowledge feeds back into their long-term management plan so if you do spot choughs out and about in Jersey please do send in your report to birdsote@gmail.com or call 01534 860059 and leave the details.

Red-billed choughs in NT Field. 5-11-2017. HGYoung

Two choughs in the NT Field, St Ouen’s Bay. 5-11-2017. Photo by Glyn Young

Chough numbers in Jersey dealt another blow

One chough who will not be venturing further afield anymore is Egg. We had a rather sad report from Ronez Quarry of a dead chough found behind the door inside one of their buildings. On collection of the body the leg rings told us the bird was a captive-raised female known as Egg. What we did not know was the cause of death since the body looked to be in good condition and time of death fairly recent. She was taken to the Zoo’s veterinary team for post-mortem analysis.

X-rays ruled out any kind of trauma. She was underweight, but there was no evidence that she starved to death. Syngamus was present, but at a very low encounter rate. Internal investigation showed problems in her lungs and presence of acanthocephalans, a type of parasitic worm also known as thorny-headed worm. Once again we cannot say for sure that these factors caused the death, but certainly played a part in her demise. We are waiting on histology results for further information.

Captive-reared chough, Egg, collecting nesting material at Sorel back in April. Photo by Liz Corry.

This brings the chough population down to 35 individuals; 12 males, 23 females. It also means we have lost a potential breeding female. Egg was partnered with Dusty and for a second year in a row had made a nest although nothing came of it. We will now need to keep watch on Dusty. Will he form a new pairing in time for the next breeding season only a couple of months away? Will Chickay finally get her chance after spending two loyal years following him? More importantly was Egg‘s cause of death a one-off or is something sinister afoot?

Julian Hume

Julian Hume and Lindsey Hubbard visited the aviary on 13th November. Julian, better known for his work with extinct bird species was excited to watch such an exuberant, and very much living, species!

Julian Hume and Lindsey 13-11-2017 (1). HGYoung

Extension request for release aviary

The release aviary at Sorel was originally granted a five-year lease of life under States of Jersey planning regulations. As this comes to an end this month we have submitted a request to extend permission a further five years.

We still have a a group of choughs using the aviary as a roost site (not to mention kestrels and barn owls). There is still a need to recapture birds for veterinary treatment as demonstrated in last month’s report. The aviary facilitates this need.

In the long term we are also looking at introducing new blood lines into the population which would require soft-release of captive reared individuals. We still aim to remove the aviary at some point in the future, but for now there is still a clear need for the structure.

More information and opportunity for public comment can be found on the States website by clicking here.

The required planning notification went up at the aviary on 9th November and has, thanks to high winds, been replaced four times!

Sorel -Site Notice 12-11-2017. Jane De St Croix

Chough report: October 2017

A few of the Jersey choughs signalling dinner time. Photo by Liz Corry.

By Liz Corry

As October drew to a close it was achingly apparent that the chough flock was down from 38 to 36 individuals. The two wild-hatched females who went missing in September had still not made an appearance, forcing us to reluctantly record them as missing presumed dead.

This is the first time we have lost wild-hatched birds post-fledging period. One can’t help feel a sense of responsibility. These individuals were known to have a nematode infection, but attempts to medicate them had failed before they went missing. All we can do now is monitor the remaining choughs to ensure the same fate doesn’t befall them.

So we did, and guess what…two of the adults started sneezing. Egg and Helier began with the ‘I’m not sneezing, just clearing my nostrils’ subtle sneeze. After a few days Egg stopped whereas Helier continued and progressively worsened.

After a few failed catch ups due to jammed hatches, intelligent corvids, and of all things Portuguese forest fires (see ‘Sepia skies’ below) Helier was finally locked in the aviary allowing her to be treated by the vet team. She was released back into the wild straight after her worming injection and appears to be much improved.

Nematodes are part of the natural ecosystem. Choughs feeding in the wild will be exposed to them and have to tolerate or succumb. This year is turning out to be the worst since the project began in terms of number of infected birds and fatalities warranting further investigation.

Sepia skies

Having worked at Sorel for several years now you would have thought that everything that could go wrong in a catch up had done or at least been theorised and accounted for. Hinges sticking on trap doors, birds not showing up or not hungry enough to want to go inside, mountain bikers zooming past scaring the flock into the air, etcetera. Not once had we thought to account for Caribbean hurricanes and Portuguese forest fires!

On the morning of the first planned attempt to catch up Helier the skies in Jersey, and parts of the UK, were looking very ominous. Walking around Sorel it felt like someone had put a sepia filter on the world. Frustratingly my camera phone kept adding its own filter so the photos below don’t fully set the scene.

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On 16th October 2017 the skies above Jersey turned a sepia colour. Photo by Liz Corry.

Low cloud filled the skies throughout the morning. Around lunchtime the sun made an appearance, but looked more like Mars than our beloved sun. There were no horsemen on the horizon so instead of embracing impending doom I turned to the Gods of Google.

A red sun breaking out from the cloud of dust and ash in the atmosphere. Photo by Liz Corry.

An explanation for the near apocalyptic conditions was provided by the BBC. Remnants of Hurricane Ophelia passing over the south of England and Channel Islands were dragging dust from the Sahara and smoke from the devastating forest fires in Portugal and Spain across our skies.

I tried explaining this to a very confused flock of choughs who were clearly conflicted about what time they should go to roost. One might think this would be advantageous to someone trying to lock birds in an aviary. Nope. Instead it meant they just sat and stared at me in their perplexed state. A twenty-minute stand-off resulted in a dejected keeper walking away left to come up with a Plan B.

Roost check

Plan B failed. In fact it wasn’t until Plan E was executed that we were able to lock the sick chough in the aviary. The new plan arose from the need to know who was roosting in the aviary in case we had to lock in the sick bird for longer than a day. There was a small chance she roosted in the aviary already rather than the quarry. If so, all we had to do was wait until the birds had gone to roost and quietly shut the external hatches.

Cut to the scene of a person in dark clothes vaulting a field gate at night only lit by the stars and the dim headlights from a teenager’s car (one assumes from the discarded firework packaging and soda cans found the next morning) idling at Sorel Point.

The operation provided extra information other than Helier’s roosting site. A total of twelve choughs were roosting inside the aviary including Dusty the very first wild-hatched chough and the two females who follow him.

Kevin and Bean were hanging around outside the aviary. They could have used one of the external roost spaces at the aviary or simply flown over from the quarry at first light to forage nearby. The other interesting find was the kestrel who shot out of the external roost box when I arrived in the morning to check on the choughs.

There are no photos from Operation If this doesn’t work we’re screwed. So instead here are a couple taken at Les Landes when checking for signs of choughs at sunset.

A view of the Pinacle at sunset. Photo by Liz Corry

Sunset at Les Landes. Photo by Liz Corry.

The Women’s Institute expedition to the north coast

Earlier in the year the ladies of La Moye WI had invited me to give a talk about the choughs. Several of their members were already aware of the project, but had not realised that the historic breeding sites for Jersey choughs were in fact along the coastline at La Moye.

Enthusiasm for the project continued to grow as the evening went on, fuelled by the obligatory tea and cake, and by the end of the night a trip to Sorel was penned in the diary.

After a few clashes in the calendar a small group from La Moye finally made it up to the north coast this month. Glyn walked them around the conservation fields and release site. Not all of the choughs were present, but certainly enough to make an impact and demonstrate their amazing flying skills. I sadly missed out as I was in England, but from the looks on their faces I think they enjoyed it.

La moye WI (1)

 

Tribute In Light: A chance to study light’s dramatic impact on bird migration

Tribute in Light, New York City. By Glyn Lowe - Flickr, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=28138731From The Cornell Lab of Ornithology: All About Birds

Billions of birds undertake migratory journeys each spring and autumn. Most of these spectacular movements go unseen, occurring under the cover of darkness. A new study provides some of the most compelling evidence yet that artificial light at night causes radical changes in the behaviour of migrating birds.

“We found that migrating birds gather in large numbers because they’re attracted to the light,” says Benjamin Van Doren of Oxford University, a lead author of the study. “They slow down, start circling, and call more frequently. They end up burning energy without making any progress and risk colliding with nearby buildings or being caught by predators.”

Scientists from the University of Oxford, the Cornell Lab of Ornithology, and New York City Audubon studied migrant bird behaviour over seven years in a truly unique setting—Tribute in Light in New York City, held to commemorate the September 11, 2001, terrorist attack. Two beams of light–each with 44 xenon bulbs of 7,000 watts—rise into the night sky, mirroring the twin towers of the World Trade Center where nearly 3,000 lives were lost.

“This was a rare opportunity to witness the impact of powerful ground-based lights on nocturnally migrating birds,” says co-lead author Kyle Horton, Cornell Lab, but working at the University of Oklahoma during the study. “This analysis would not have been possible without the help of tribute organizers.”

Well before the results of the study highlighted the effects of the installation, New York City Audubon reached out to the original tribute organizers, the Municipal Art Society, to let them know about the impacts of artificial light on migratory birds. In 2002, the two organisations developed a protocol to save the affected birds. The tribute lights are turned off for approximately 20 minutes when more than 1,000 birds are seen circling in the beams or flying dangerously low with frequent calling. The National September 11 Memorial & Museum, which took over as tribute organisers in 2012, continued this practice.

Tribute In Light

These brief interludes of darkness during the nightlong tribute provide a unique opportunity for the scientists to quantify changes in bird behaviour in several ways during the alternating periods of light and darkness.

“We had more than 20 wonderful volunteers on the ground counting birds to confirm what was happening in the beams,” says co-author Andrew Farnsworth at the Cornell Lab. “We also used remote sensing tools, including data from local National Weather Service radars, to understand the density and movements of the birds. Acoustic monitors recorded call notes and captured the vocal behavior of birds in the beams. And we ran computer simulations to try to better understand the dynamics of the patterns we were observing.”

When the tribute was illuminated, the study’s authors found that densities of birds over lower Manhattan could reach 60 to 150 times the number that would typically be found in the area at that time. The concentrating effects of the intense light on the birds reached as high as 4 kilometres (2.5 miles). The impact on birds was consistent even on clear nights. (Many previous artificial-light studies focused on nights with poor visibility.) When the light beams were turned off, the birds dispersed within minutes to continue their migrations.

Although Tribute in Light provided a way to measure a specific instance of light attraction, bright nighttime lighting poses problems for birds, even in rural areas. The study’s authors point out that one solution is relatively simple.

“We recommend building lights be turned off for as much of the night as possible, but at least from midnight to dawn during migration season,” says study co-author Susan Elbin of New York City Audubon. “This is true for areas around homes as well as other brightly lit areas such as sports stadiums, construction sites, offshore oil rigs, and large buildings. Migrating is already hard enough for birds without this added danger from artificial light at night.”

The full paper High-intensity urban light installation dramatically alters nocturnal bird migration can be accessed here

Alarm over decline in flying insects

Comma. Photo by Mick DrydenFrom BBC News

It’s known as the windscreen phenomenon. When you stop your car after a drive, there seem to be far fewer squashed insects than there used to be. Scientists have long suspected that insects are in dramatic decline, but new evidence confirms this.

Research at more than 60 protected areas in Germany suggests flying insects have declined by more than 75% over almost 30 years. And the causes are unknown. “This confirms what everybody’s been having as a gut feeling – the windscreen phenomenon where you squash fewer bugs as the decades go by,” said Caspar Hallmann of Radboud University in The Netherlands.

“This is the first study that looked into the total biomass of flying insects and it confirms our worries.”

Bumble bee. Photo by Mick Dryden

The study is based on measurements of the biomass of all insects trapped at 63 nature protection areas in Germany over 27 years since 1989. The data includes thousands of different insects, such as bees, butterflies and moths. Scientists say the dramatic decline was seen regardless of habitat, land use and the weather, leaving them at a loss to explain what was behind it. They stressed the importance of adopting measures known to be beneficial for insects, including strips of flowers around farmland and minimising the effects of intensive agriculture.

And they said there was an urgent need to uncover the causes and extent of the decline in all airborne insects. “We don’t know exactly what the causes are,” said Hans de Kroon, also of Radboud University, who supervised the research. ”This study shows how important it is to have good monitoring programmes and we need more research right now to look into those causes – so, that has really high priority.”

The finding was even more worrying given that it was happening in nature reserves, which are meant to protect insects and other living species. ”In the modern agricultural landscape, for insects it’s a hostile environment, it’s a desert, if not worse,” said Dr de Kroon. ”And the decline there has been well documented. The big surprise is that it is also happening in adjacent nature reserves.”

Honey bee. Photo by Mick Dryden

The loss of insects has far-reaching consequences for entire ecosystems. Insects provide a food source for many birds, amphibians, bats and reptiles, while plants rely on insects for pollination.

The decline is more severe than found in previous studies. A survey of insects at four sites in the UK between 1973 and 2002 found losses at one of the four sites only.

Dr Lynn Dicks, from the University of East Anglia, UK, who is not connected with the study, said the paper provides new evidence for “an alarming decline” that many entomologists have suspected for some time. “If total flying insect biomass is genuinely declining at this rate (around 6% per year), it is extremely concerning,” she said. “Flying insects have really important ecological functions, for which their numbers matter a lot.”

Download the full report More than 75 percent decline over 27 years in total flying insect biomass in protected areas here

Already vulnerable British birds are likely to be the worst affected by climate change

Common snipe. Photo by Mick Dryden (2)From RareBird Alert

Latest research by the British Trust for Ornithology (BTO) has found that, although several birds may benefit from a changing climate, particularly in the north, some species will be hit hard and among these are some of the most vulnerable British birds.

Researchers have long investigated the effects that climate change might have on where different species might occur in the future. However, for the first time, scientists at the BTO have investigated how climate change will affect how common different species are likely to be across Great Britain.

Analysing data for 124 different bird species allowed scientists to understand how the whole bird community might change as a consequence of climate change.

Several species (55 of the 124 considered in this study) are likely to benefit from future climate change and their populations may increase significantly by 2080. In contrast, fewer species (11 of 124) are likely to suffer from climate change. This may apparently look like good news, but in reality six of the 11 species that are projected to decline are already included in the British red list of the birds that are at highest risk of local extinction (grey partridge, curlew, grasshopper warbler, ring ouzel, pied flycatcher and yellowhammer), two, curlew and yellowhammer, are on Jersey’s red list (here), and four (red grouse, common snipe, willow warbler and meadow pipit) are currently in the amber list (willow warbler is red on Jersey’s red list!). These species will be at even greater risk of extinction if urgent actions are not taken to improve the habitats and landscapes they require to give them a chance to adapt to climate change.

Ring ouzel (3). Photo by Mick Dryden

In contrast, 40 of the 55 species that are likely to increase are either green-listed, which means they are not currently threatened, or do not yet breed in Britain. This highlights how climate change will more seriously hit those species that are already of conservation concern.

Dario Massimino, Research Ecologist at BTO, and lead author on the paper, said, “This is the first time that count data have been used for future projections on such a large-scale and for so many species, and the findings are very interesting. Gains in the north and west, apparent stability in the south-east and a worsening scenario for those species already in precipitous decline. Without the dedication of BTO volunteers who collect the observations, this type of analysis just wouldn’t be possible; thank you to them all.”

Dr Mark Eaton, RSPB Principal Conservation Scientist said: “This paper serves as a clear warning that we must rise to the challenge of climate change if we are to avoid seeing species disappear from the UK. We already know that climate change is among the greatest long-term threats to our wildlife and research like this is invaluable by identifying the individual species that could be lost if we fail to act. Using the findings of this work we can plan for the future and the role the UK must play in protecting vital habitats and helping species adapt to a changing world.”

Among the 124 breeding bird species, researchers also considered some which are not yet present in Great Britain but could potentially colonise if they take advantage of higher temperatures. To achieve this, data from the UK Breeding Bird Survey were combined with data from its French counterpart (the Suivi Temporel des Oiseaux Communs). French data were included to better understand how species respond to warmer temperatures that are found in France but yet to occur in Great Britain, and to consider potential colonists such as melodious warbler and tawny pipit.

Tawny pipit. Photo by Mick Dryden

As a consequence of these responses to climate change, different regions of Britain will see net gains and losses in bird numbers. The projections show that the largest gains will mostly be in northern and north-western Scotland and other smaller areas of western Britain. The south-east shows apparent stability, but this is a result of potentially large declines in red-listed species and compensating increases in green-listed species. We are likely to see dramatic changes in the bird community throughout British Isles, but in particular in the west of Scotland.

The full paper Projected reductions in climatic suitability for vulnerable British birds can be accessed here

Seventy four percent of seabirds ingesting plastic

- 006From 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.”

- 007

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

Puffin. Not in Jersey. Photo by Mick Dryden

Storm petrels heard on Shiants for first time. Back in Jersey soon?

European storm petrel. Photo by Mick DrydenFrom 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 petrel (3). Photo by Mick Dryden

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.

Storm petrel (4). Photo by Mick Dryden

Migrating birds might not be able to fly home fast enough to meet shifts in springtime

Willow warbler. Photo by Mick DrydenFrom 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.

Tree pipit. Photo by Mick Dryden

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.”

Pied flycatcher. Photo by Regis Perdriat

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

 

Barn swallow (2). Photo by Mick Dryden