Counting Jersey’s birds in 2014

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Red-backed shrike. Photo by Duncan Wilson

Once again our team of hardy, stalwart bird counters has gone out in whatever Jersey’s weather can throw at it to record birds across the Island. To give you some idea of the effort that the team put in in 2014, 540 data sheets were submitted from the 22 transects. That equates to around 50,000 bird sightings, recording more than 70,000 individual birds during the year. That’s a lot of birds counted. Especially as we don’t include herring gulls!

Highs and lows

Highest bird numbers are typically recorded from the St Ouen’s Pond transect because we often see large flocks of some species there. During the autumn migration almost any of the transects can get very busy as there may be an almost constant stream of wood pigeons, meadow pipits, swallows, chaffinches or redwings overhead. It is sometimes difficult to concentrate on those birds at ground or bush-level when the sky is full of finches; indeed, it is possible to lose interest in chaffinches some days! By contrast, mid-summer days with no migrants and resident birds moulting can seem very relaxed. That’s when I find butterfly numbers pencilled onto the forms.

Wood pigeon leaving Noirmont. Photo by Mick Dryden

And the worst, the lowest count received? Awful weather, especially high winds, horizontal rain, thick sea-fog (think of a Jersey summer) can really dampen bird activity and counter enthusiasm. However, for sheer rubbish, Miranda’s count of 28 birds across the two Les Landes transects in late-August takes some beating! This count, surprisingly included a common redstart, three stonechats and five wheatears, which didn’t say much for the resident birds up there. Miranda did have to put up with an F5 wind and heavy rain though and other counters have reported F9 winds and thick fog from visits where the expletives written into the margins of the forms give a more realistic interpretation than the requested weather info.

Citizen science

Firecrest. 2014

Firecrest records from two eastern woodland sites in 2014

So, why do so many people get out there and count birds all year? What is the reward? Well, it has been suggested that we bury chocolate bars and soft drinks along the transects as a bribe. However, in fact, taking part in such a big project is reward in itself. In December we received the 3,000th completed recording form: one of Tim’s from Les Blanche Banques. In April 2015 we will have been collecting data from five sites for 10 years and we will celebrate by Firecrest. Photo by Mick Drydenshowing exactly what has been happening to many of birds (spoiler alert: it may not all be good news). Can you imagine the power of these results? This is citizen science at its most productive so we are indebted to Miranda and to Jess, Cris, Harriet, Harri, Sally, Neil and Ali, Tim, Tony, Jon, Jonny, Neil and Glyn and all the National Trust Rangers for the incredible effort they put in throughout the year.

A true birder’s reward and the one that got away

However, if you were to ask any of the counters if there was any other reward for getting out there to do the counts they would, no doubt, under bribery of those chocolate bars and soft-drinks, tell you that there was actually one, very un-scientific, reward. There is always that chance of seeing a bird that you weren’t expecting. Or that no one expected. 2014 was no exception and 10 new species increased the list to 170 Woodchat shrike. Photo by Harriet Whitfordrecorded on the transects. Some of these were at St Ouen’s Pond where, although we don’t count the birds of the open water (so no grebes), habitat not found elsewhere on the survey does throw up a few new species like the first jack snipe and grey plover records in 2014.

Real megas (a term us birders use I’m afraid), however, during the year did include a remarkable flock of 16 black-winged stilt that dropped in on the St Ouen’s Pond transect, a great white egret at Gorselands (Glyn hasn’t even seen a great white in Jersey yet), a juvenile red-backed shrike that was seen on two visits to St Ouen’s Pond, a woodchat shrike at Noirmont, cattle egrets at Les Landes and even a rook! Mind you, we missed the great-spotted cuckoo that literally stood on the transect the day after a count.

Black-winged stilt. Photo by Mick Dryden

When projects meet

We have been very fortunate that the cirl buntings had a very good year and at least one pair stayed on one of our transects all year. That makes keeping an eye on them easy. And the red-billed choughs? Well, we knew that they would eventually be recorded on at least one transect and were looking forward to records first from the Sorel transects and then from any of the others. Bets were placed! Well, at the end of the year we had recorded them at Les Creux, Crabbé and Grantez. They did visit the sites at St Ouen’s Pond, Gorselands and Les Landes too, but, disappointingly, not on count days.IMG_5185

JARG Day 2015: Habitat Conservation for Amphibians and Reptiles

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Grass snake in Jersey. Photo by Rob WardThis year’s Jersey Amphibian and Reptile Group (JARG) Day will be held on 14th February from 09:30 – 15:30 at the Frances Le Sueur Centre, St Ouen.

jargThis year the theme is Habitat Conservation for Amphibians and Reptiles and there will be talks from local and UK experts, followed by workshops and field work sessions about local amphibian and reptile identification and survey methods and protocols.

arc-logoThis annual event is open to everyone whether you are interested in learning more about local biodiversity; you are an existing volunteer recorder for JNARRS (Jersey National Amphibian and Reptile Recording Scheme) or would like to learn about becoming a recorder for the first time.

JBP logoThis event is free to attend, however, booking is essential as places are limited and will be allocated on a first come first served basis.

This year’s agenda

09.30 –10.00 Arrive (tea/coffee)

10.00 -10.30 Dr John Wilkinson, Amphibian & Reptile Conservation (ARC): Introduction.

10.30 – 11.00 Peter Hill (ARC): Herpetofauna habitat management, how we do it in Wales.

11.00 – 11.30 Sally Dalman, Countryside Ranger, National Trust for Jersey: Relocation, relocation, relocation – How I became a lizard stalker for the summer.

11.30 – 12.00 John Buckley (ARC): Natterjack toad conservation – the long view plus An update on pool frog reintroduction programme.

12.00 – 12.30 Lunch

12.30 –13.00 Nina Cornish, States of Jersey: Jersey National Amphibian & Reptile Recording Scheme (JNARRS) 1st cycle results.

13.00 – 15.30 Dr John Wilkinson (ARC) will lead the workshops.

Workshops
                    Training in amphibian and reptile identification, habitat assessment,
survey methods, survey protocols, recording, health & safety etc.

For more details or to book a place please contact Julia Meldrum: Telephone: 441665 Email: j.meldrum@gov.je

Please note that the afternoon session will include field work, so please come prepared with suitable clothing and footwear for the weather conditions as we will go ahead come rain or shine!

Bufo bufo male2 JWW

Local birds increasingly likely to stay at home this winter

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Robin (3). Photo by Mick Dryden

Two technical reports just published confirm what local birdwatchers have long known: some of our migratory birds are staying much closer to home in winter these days.

Climate warming and other environmental changes seem to be causing a shift in the wintering grounds of European birds northwards. This was tested in two studies, one looking at numbers of some common northern-European songbirds including robins, chaffinches and wagtails that winter in Spain and one looking more specifically at robins. These birds are partial migrants, species where parts of the overall population are migratory while others remain in place, not like swallows or redstarts whose whole population migrates south. The studies looked at annual numbers reaching Spain using data from recoveries of ringed birds.

White wagtail. Photo by Regis PerdriatResults showed that the numbers of the study species from outside of Spain reaching there in winter has decreased since the 1980s and probably well before. This tendency had to be checked against the species’ overall population numbers in northern Europe to make sure the birds weren’t just getting rarer anyway, and, as they weren’t, this confirmed that these birds are moving less. An understanding of the species’ preferred diet did show some likely patterns since frugivorous (fruit-eating) birds, a group well adapted to tracking changes in food availability, showed sharper reductions in numbers reaching Spain in winter than the more insectivorous species. In addition, larger birds, such as thrushes, less affected by problems of winter temperatures, reduced their migratory movements to the south more than small birds. The results suggest a long-term rearrangement of migratory movements of European birds in which the Mediterranean basin is losing its traditional role as primary wintering ground for many of our birds.

Blackcap. Photo by Mick Dryden

The reduction in numbers of wintering migrant birds in Spain appears to have been taking place since at least the 1970s. However, this reduction may have been in progress earlier, since several partially migratory songbirds began to winter in northern Europe in the mid-twentieth century and earlier. The ability of wintering blackcaps, thrushes and, to a lesser extent, robins to move according to fruit resources is most often observed in their wintering grounds, where their abundances are regulated by the annual availability of fruits. The reported changes in the migratory behaviour of the blackcap, one frugivorous species for which foreign recoveries in Spain has declined despite the sharp increase in the European population, support this interpretation. This change of migratory schedules in blackcaps has been related to this species’ ability to adapt its migratory journeys to increasing food availability offered by urban areas in central Europe and warmer coastal areas like the Channel Islands. Why fly all the way to Spain if you can stay at home or move to someone’s garden?

Partial migratory birds possess the genetic variation required to change from partially migratory to resident in just a few generations, suggesting that, according to current predictions of global warming, such trends will continue to increase the number of sedentary populations in Europe and to reduce the number of overwintering birds in the Barn swallow in Jersey. 16 December 2014 (2). Photo by Mick DrydenMediterranean. In the Channel Islands we have seen big changes in our wintering birds over the last 25 or so years. Fieldfares hardly bother to come here now unless the weather turns really cold whereas the UK is full of them. In their place (but not necessarily in the same habitat) we see lots of chiffchaffs and blackcaps. Interestingly, as reported elsewhere in Europe, our wintering blackcaps are very much a bird of the garden where they hog the feeders rather than out in the wider countryside where they’ll later breed.

What of the true migrants? Well, although this winter we have had several swallows and a wheatear sticking around, these species are unlikely to change their habits very soon.

Read the paper abstracts:

Are European birds leaving traditional wintering grounds in the Mediterranean?

Has the Number of European Robins Erithacus rubecula Wintering in Spain Decreased?

Robin (4). Photo by Mick Dryden

 

 

Chough report: December 2014

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Bean 2By Harriet Clark

December was another quiet month for the choughs, and it seems, for now at least, their exploratory days are over. The birds rarely ventured further than half a kilometre from the aviary, apparently content probing for insects in the grazed fields near the aviary. The ten juveniles were at least a little more adventurous than the older six birds however, and for the first few weeks in December, could faithfully be found every morning, perched on the muddy cliffs at the mouth of Mourier Valley, digging furiously, doing what looked like some impressive excavation work!

Chickay, Bean and co digging on their “favourite” cliff. Photo by Harriet Clark

Chickay, Bean and co digging on their “favourite” cliff. Photo by Harriet Clark

Quite what the birds were finding there is unclear, but our pitfall trapping showed that there were still plenty of insects about, including rove beetles, ground beetles, minotaur beetles, earthworms and leatherjackets. Leatherjackets (crane fly larvae) are known to be a favourite food item for choughs, and this is certainly evident with our birds as they excitedly, and rather comically, chase each other when one chances upon the prized invertebrate prey.

Unsurprisingly December brought more downpours, fog, gale force winds and hail, but I am thrilled to say that the choughs have battled through, all in good health. We only had one morning of heavy frost, and interestingly, early that day the birds were nowhere to be seen in the usual grazed fields.

Handfuls of leatherjackets to be found! Photo by Harriet Clark

Handfuls of leatherjackets to be found! Photo by Harriet Clark

We eventually tracked the flock to Mourier Valley, and found them foraging amongst the dead stands of bracken. We hadn’t observed the birds foraging there before, but closer inspection revealed the soil was very soft, and presumably easier to probe for insects in than the harder ground of the grazed fields. Will, Jennifer and I also adapted to the windier, wetter weather and located several “good” gorse bushes to huddle beneath or, in Jennifer’s case, lie flat on her back underneath, just to have a bit of a break from the pounding, relentless wind!

The flock flying over a frosty Mourier Valley. Photo by Will Campbell

The choughs weighing themselves in the aviary. Photo by Harriet Clark

The choughs weighing themselves in the aviary. Photo by Harriet Clark

December marked seven months of living free for the older birds, and three months for the juveniles. Faecal samples were submitted to the laboratory at Durrell as part of our continuous post-release health screening. The results were very encouraging and showed that the birds’ parasite load has decreased since their last screening in October. We also monitor their health by weighing them, and we now have a second set of scales so that when the weather allows we can weigh as many individuals as possible. Despite halving the quantity of dry mix and insects that we feed the choughs in October, regular weighing shows that the birds definitely aren’t suffering from lack of food, with several even putting on weight. This and their low levels of parasites, indicates the birds are clearly maintaining good body condition and are acclimatising well to their environment.

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Sorel is ideal habitat for minotaur beetles, which prefer short grazed turf and plenty of sheep dung for the larvae to feed on. Photo by Harriet Clark

The older choughs developed a new habit this month; during feeds they would collect several mealworms or a “beakful” of dry mix and fly out of the aviary, disappearing out of sight to a nearby field. At first we wondered whether they were simply taking their food away from the group to eat it in peace, but careful observation revealed that although sometimes they were eating it, other times they were digging a hole and hiding the food in there. Choughs caching mealworms has previously been observed by Eric Bignal in his study of supplementary feeding wild choughs in Islay (report published in British Wildlife), and the birds there were seen marking their caches with different objects such as feathers, to aid finding them later. Although we feed our choughs twice a day, they don’t receive a huge amount and it is quickly consumed, so perhaps the adults are caching food so that they have access to it later in the day.

Evidence of choughs at work. Photo by Will Campbell.

Evidence of choughs at work. Photo by Will Campbell.

At the beginning of the month we started to notice several muddy patches scattered randomly across the sheep grazed fields. We quickly discovered the culprits- the choughs of course. They seem to have developed a penchant for tearing up the grass, and we’ve observed the group many times this month energetically flinging clumps of grass into the air, no doubt searching for soil invertebrates to feed on.

Icho and three of the adults tearing up the grass in search of insects. Photo by Harriet Clark

Icho and three of the adults tearing up the grass in search of insects. Photo by Harriet Clark

The adult female Mauve, finally gave up pursuing her previous partner Green this month, focussing her attention instead on the two-year-old male White. We monitor the location and activity of the birds hourly throughout the day, and White and Mauve are almost always found foraging close together, often separate from the rest of the group. During supplementary feeds the pair also feed from the same dish, and regular roost checks throughout the month revealed that rather than returning to the aviary with the rest of the group at sunset, they roost together in the quarry. Fingers crossed we may now have two potential breeding pairs to keep an eye on in 2015!

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Regular visitors to Sorel will undoubtedly have noticed significantly fewer sheep out and about on the north coast towards the end of the month. Unfortunately several young sheep were taken ill and because it was not clear at first what the problem was, the flock was moved into the fenced-off aviary field for close monitoring and care by their shepherd Aaron Le Couteur (CS Conservation). Test results revealed the sheep had a gastro-intestinal problem, and, being a primitive breed, they have physiological differences so often respond differently to parasites compared to commercial sheep breeds. The flock has now been treated with a novel drug and are fortunately well on the road to recovery.

Choughs foraging alongside the sheep in the aviary field; wherever the sheep go, the choughs go too! Photo by Harriet Clark

We sadly said goodbye to Will at the end of December, after four months on the project. He started volunteering one week after the juveniles were released and has been following their progress ever since, spending many hours radio tracking the birds across the island and observing their antics on the cliff tops at Sorel. Will has been a huge help both in the field and in developing our invertebrate monitoring project. We wish him every success as he moves to England to pursue a career in wildlife conservation. You can read his brilliant piece about his time on the project here

Will recording the location of a foraging site commonly used by the juveniles. Photo by Harriet Clark

My time with the choughs – it’s not all sunshine on Jersey’s north coast

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By Will Campbell

In October Adam wrote about his time with the choughs on the sunny north coast of Jersey. However, it’s not all sunshine and calm days on our coastline and here Will recounts his time following the choughs into a Jersey winter.

My toes are numb as I squeeze my way past gorse bushes and through muddy fields, arm and radio antenna outstretched, feverishly waiting for the reassuring ‘pip’ from the SIKA that indicates a nearby chough. Because, once you have found one chough (the ‘Judas chough’ as fellow volunteer Jenny calls them), you can be pretty sure that the others are nearby.

Radio receiver in fog. Photo by Liz CorryI trudge, stooping into the wind, to a high point and wave the antenna in every direction for what seems like the hundredth time. At last a faint ‘pip’ comes through the SIKA slung over my shoulder. I look anxiously ahead into the wind and rain but instead of the familiar acrobatics of a chough I see nothing but a thick sea mist. Dejectedly I trudge on, in the vague direction of the ‘pip’ in order to pinpoint their location.

It’s at times like these when some people might ask, ‘Why?’ And I tell them that although data collection isn’t easy, no matter how minute and irrelevant it may seem, it is absolutely necessary to build the bigger picture. A big part of my time with the choughs was spent radio tracking them – essentially finding out where they were and how far they were from their mates. Doing this up to eight times every day allows you to amass a huge amount of data, which can in turn help answer loads of questions in matters such as social sub-groups, home range, and even potential breeding pairs and nest sites come the spring.

IMG_5200Although I’ve painted a pretty grim picture at the start of this piece, I did in fact experience all four seasons in my four months up on the north coast, sometimes, it seemed, in the space of one day. At 8am I might be huddled with the sheep in what little shelter there was from the wind and rain, and by 11am I could be sunbathing in a field, cursing myself for forgetting my sun cream.

The most extreme weather I faced up at Sorel was during gale force 8/9 winds where simply walking from A to B was a challenge. Even the choughs were wisely sheltering in the aviary from the onslaught. Harriet and I noticed an upturned kayak in the sea and, fearing the worst, she called the Coastguard. It didn’t take long for a search plane to arrive and start scouring the sea. Luckily, it turned out the kayak had never been occupied and the plane turned back to what must have been a very bumpy landing.

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It was during the warmer half of my placement that the choughs decided to clock some air miles and check out what the rest of the Island had to offer. This left us frantically driving around the west of Island, but ‘as the chough flies’ is a much quicker way of getting around than ‘as the Skoda drives’. It was only due to the very welcome tip-offs from local bird-watchers that we were able to find the choughs down at Beauport probing amongst the cliffs; apparently oblivious to the panic and excitement they caused us. It was incredibly rewarding to see the previously captive birds exploring the island and always making it back to the aviary with impeccable timing to demand their lunch.

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The choughs seem to have an uncanny ‘spider sense’ when it comes to feeding time. The idea is that, once you have put out the dishes, you give a tinnitus-inducing blow of a whistle and the choughs appear in unison to merrily scoff all the food. The birds have been trained to the whistle to try and give us an element of control, for example if they need to be shut in the aviary. In practice, however, the choughs are canny little birds and seem to react to the subtlest of cues such as the gentle clinking of dishes, the opening of a door or even a Durrell jumper walking towards the aviary. The result is always the same. By the time you have put the dishes out and raised the whistle to your lips all 16 birds will be lined up along the exterior aviary shelf, begging with their wings open and squawking to express their irritation at having to wait for their dinner. During the afternoon feed, when insects are scattered and hidden in pine cones and under logs, you have the delight of witnessing an ‘Easter Egg Hunt’ as the birds frantically waddle around the aviary trying to be the first to find the delectable wax moth larvae.

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Another ongoing study that I was involved with was a pitfall-trapping survey in order to gather information about the choughs’ available food sources. Unfortunately I didn’t have the chance to look into the other end (literally) and sift through chough poo to see what they were actually eating. As I have a weird fascination with invertebrates and had gained some experience in stream-dwelling bugs during my degree, I was appointed the authority on all things creepy and crawly and was instructed to create a pictorial guide to the invertebrates previously found at Sorel. This soon turned into an 80+-page monstrosity that I sincerely hope will be of use to the other volunteers and staff (other than to prop up their computer screens).

It was a challenge at first to identify the unique coloured rings around the legs of each bird, let alone remember which bird the rings belonged to. But after a while you can even guess which birds hang out together and, at the risk of anthropomorphizing our feathered friends, understand their individual characters. The love triangle between Dingle, Chickay and Caûvette (and Caûvette’s incessant whining) wouldn’t be out of place in an episode of EastEnders.

Although you shouldn’t choose amongst your children, Chickay is definitely my favourite. When you watch the choughs for as many hours as I have you see them do some pretty bizarre things. It always seemed to be Chickay that would hang upside-down from the aviary netting like a bat, groom a sheep or chase butterflies with her peculiar waddle.

Chickay. Photo by Liz Corry

Reluctantly, my time with the choughs has come to an end. It has been a great experience working on the reintroduction project, and to be part of such an important and exciting project in its infancy. All that is left to say is a big thank you to Liz, Harriet, Glyn, Jenny and everyone at Durrell for making my placement unforgettable. And, of course, thank you to the 16 choughs (you know who you are) that kept me company up on the cliffs. Oh, and thanks of course to the sheep for sharing their best spots to shelter from the rain. I sincerely hope that all the hard work, dedication and frostbite bears fruit once it comes to the breeding season!

Keep up the great work!

Red-billed chough and common buzzard. Sorel, Jersey. October 2014. Photo by Nick Parlett (4)

Effects of the 2014 storms becoming apparent in Wales

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Puffin 2 low res. Photo by Paul MarshallFrom BirdGuides

As we begin to see the first serious winter storms of the year around the British coastline, research in Wales is revealing the full consequences of last winter’s exceptional storm activity amongst our seabird populations. Dr Matt Wood, from the University of Gloucestershire, is helping to uncover the consequences for the thousands of puffins on Skomer Island, in Wales.

Around 50,000 dead seabirds, including puffins, guillemots and razorbills, were washed ashore in a severely emaciated state — they’d essentially starved as storm after storm prevented them from catching enough fish to eat. With unknown numbers dying out at sea, this was the biggest seabird wreck recorded in Europe. By the end of 2014’s breeding season, the numbers of adult puffins returning breed was down by 25% on the previous year: a quarter of the birds on Skomer and Skokholm islands in Pembrokeshire may have died before the season started, totalling around 5,000 individuals. Three guillemots ringed in Skomer were picked up dead on Jersey beaches.

Razorbill (2). Photo by Mick Dryden

Dr Wood commented: “Puffins typically live in large island colonies, seabird cities if you like. Now take a city like Cardiff and imagine what would happen if a quarter of people didn’t come back after the Christmas holidays; by mid-January things would be going seriously wrong, and it looks like that’s what happened to the puffins”.

Field assistant Ros Green found that Skomer puffins bred unusually late, their chicks hatching two weeks later than usual and being fed at only a third of the rate in 2013. As a result, breeding success dropped markedly by 25%, with only just over half of pairs raising a chick. It proved the worst year on record for puffins on Skomer, in the 43 years of the study (since 1972).

Dr Wood added: “The long-term seabird studies on Skomer are an amazing resource. One of the puffins that was still around until recently was first seen in 1973, the year I was born.

“With studies like this, with birds we know and study as individuals, we can understand how populations work in the detail we need to face the challenges of the future. Will more storms impact seabird populations? I’d say ‘probably, yes’, but it’ll take us years to get a true picture of what happened in 2014, and only long-term monitoring at key sites like Skomer can provide reliable answers to questions like that.”

Long-lived seabirds like puffins can take a gap year if times are tough, but Dr Wood believes that the numbers of birds washed up dead on beaches last winter are little cause for optimism. He concluded: “Seabird wrecks are not unprecedented, these are tough little birds that can usually cope with a storm, but forecasts of global climate change predict that these extreme storms will become bigger and more frequent. The effects of the recent seabird wreck will only become clear over the next five to ten years: long-term studies are vital to understand how the populations will cope in the future.”

The Skomer and Skokholm seabird reports are published online here

Puffin. Photo by Regis Perdriat

Trends in numbers and breeding success of UK breeding birds now online

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Mistle thrush. Photo by Mick DrydenFrom British Birds and the BTO

The BTO’s latest BirdTrends report published online, summarises the population trends for 120 breeding bird species across the UK using data collected by volunteers including those in the Channel Islands. For the first time, this year’s report provides habitat-specific trends for many species, highlighting those habitats where species are in trouble. As is becoming all too familiar, while intensive conservation efforts and targeted habitat management have benefited some rarer UK bird species, many widespread and formerly common birds are experiencing severe declines. Some 28 species, almost a quarter of those included in the BirdTrends report, have exhibited falls in numbers greater than 50% over the last 35–45 years.House sparrow (3). Photo by Mick Dryden

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House sparrow population in England 1976-2013. From BTO http://blx1.bto.org/birdtrends/species.jsp?s=housp&year=2014

‘National declines in farmland birds are well-documented and these latest figures show that this decrease is continuing,’ explains the report’s lead author, Senior Research Fellow Stephen Baillie. ‘The results of BTO surveys show that many familiar garden birds are also experiencing problems. House sparrow numbers have dropped by almost 70% since the 1960s and the data suggest that sparrows occupying urban and suburban habitats are faring worst.’

‘The range of garden birds experiencing population declines appears to be increasing,’ explains report co-author John Marchant. ‘While many will be familiar with the disappearance of house sparrow, starling and spotted flycatcher, it may surprise people to know that house martin, mistle thrush and greenfinch are heading in the same direction. Again, there is evidence that house martin and mistle thrush declines are most pronounced around human habitation; the BTO will be launching a volunteer house martin survey in spring 2015 to find out more about the current distribution of breeding populations in order to identify and inform conservation measures.’

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Turtle dove population in UK 1966-2013. From BTO http://blx1.bto.org/birdtrends/species.jsp?year=2014&s=turdo

So what can be done to reverse these declines? ‘We urgently need more data to answer that question, and volunteer surveyors can provide it,” explains Dave Leech, a Senior Research Ecologist at BTO. ‘Information generated by ringing birds and monitoring their nests proved that the majority of farmland bird declines were driven by a reduction in food availability during the winter. Drivers of garden bird declines are more variable; reduced winter food availability and disease appear to have caused a fall in starling and greenfinch numbers respectively, whilst house sparrows seem to be struggling to rear enough chicks. Data gathered by BTO ringers and nest recorders will help us to identify the mechanisms underlying declines of other species.’

There is, however, far more to the BirdTrends report besides the species pages! Supporting pages describe the field and analytical methods that were used to produce the results for each species and to identify alerts. Overall patterns of trends in abundance and breeding success are discussed, and compared with the latest trend information and alerts with the Birds of Conservation Concern list. Summary tables list alerts and population changes by scheme, and there is also a facility to select and display your own tables of population change. A detailed References section lists more than 700 of the most relevant recent publications, with onward links to abstracts or to full text where freely available, and is a valuable key to recent scientific work by BTO and other researchers. The Key findings page provides a brief overview of our main findings this year.

Text, tables, graphs and presentation for each species are updated annually to include the latest results and interpretative material from the literature. Information on demographic trends and on the causes of change is gradually being expanded. There are new pages this year for gadwall, little egret and common tern.Gadwall. Photo by Mick Dryden

Nest-boxes, new homes for choughs

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DSC01433By Liz Corry

Last month we gave you an insight into Cornish choughs and what people are doing there to help them. This month we continue our travels and will take you north across the border to Wales. Known for its lush valleys and majestic mountains, Wales is also home to about three-quarter’s of the UK’s choughs.

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www.visitwales.com

The Welsh name for a chough is brân goesgoch meaning ‘red-legged crow’.

Wales is broadly categorised into four regions; north, mid, west, and south. Choughs can be found more or less along the entire Welsh coastline from the Gower Peninsula in the south to the isle of Anglesey in the north.

They can also be found inland from the coast nesting in abandoned quarries or mineshafts. Most famously at the Llechwedd slate caverns , North Wales, where a pair are known to nest much to the delight of the tourists deep underground. A video made by the RSPB gives you more of an insight and can be viewed here.

Over the past two decades researchers working with these choughs have seen more and more inland nests becoming abandoned and breeding pairs disappearing. Ceredigion had five breeding sites in the late 1980s. Ten years later it was down to one. Montgomeryshire has seen a complete loss. It is believed that the boom in natural predator numbers, namely peregrine and goshawk, has not helped matters.

Silurian shale coastline in Wales.

Silurian shale coastline in Mid Wales.

Coastal nest sites are also under threat, but in this case it is due to natural erosion. A lot of the coast is limestone, sandstone, or shale and easily erodes. Looking at the photo on the right you wouldn’t think a bird would chose to build a nest on these cliffs. Yet they do, often with success, although a few years down the line the ledge might give way falling into the sea and a new nest will need to be built.

Nest-site availability is a very strong limiting factor in population expansion. In the late 1980s Scottish researchers had already shown the effectiveness of providing choughs with artificial nest-sites. Wales took on board this advice and started providing nest-boxes or ledge supports at various coastal sites. Within a few years just over two thirds of the artificial sites were being used. As of 2008 choughs at 22  artificial nest-sites successfully raised a total of 335 fledglings!

On a recent holiday to Wales I had the privilege of meeting Tony Cross, a champion chough supporter and the person responsible for designing the artificial nest-boxes (which we use at the Wildlife Park). Tony very kindly spared time to show me around some of the sites and teach me more about the Welsh choughs. Having ringed over 4,000 choughs and followed many individuals for several years there is a lot we can learn from him.

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This area was once used by choughs to raise chicks, but has now been abandoned.

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An abandoned mine shaft once used by nesting choughs.

The first stop was at an abandoned mining area where a pair of choughs used to nest. It is hard to see from the photos, but they chose a spot down a deep shaft which kept them fairly well protected from nest predators.

The land around looks quite healthy in terms of insect availability with cattle grazing pastures and its away from built up areas.

This is probably one of those sites which ‘suffered at the talons’ of the goshawk (although great news for the goshawk I guess).

As it was outside of the breeding season we didn’t disturb any nesting choughs. Tony is a licensed ringer and licenced to approach nests. I would not have been able to do this without him.

We then drove to the coast to take a look at some of the nest-boxes Tony and his colleagues have fitted to the cliffs. It is quite a challenge as they have to find a site that they can access, but at the same time deter egg collectors and the like from reaching it. In recent years Tony has sadly found activity at boxes suggestive of human raids rather than natural predators (and we thought those days were over). One clue being that ravens don’t need to use ropes!

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Nest-boxes are positioned away from potential land predators in areas where choughs are trying to breed naturally but fail.

The boxes are constructed from either marine grade plywood or Ecosheet©, a recycled plastic boarding. The shape is designed to mimic a natural cavity so they are quite narrow and deep.

Tony Cross indicating how far back the nest box reaches.

Tony Cross indicating how far back the nest-box reaches. This one is unusual in that it is positioned on top of the cliff.

The front of the box has and overhang which, apart from acting as a deterrent to something trying to reach in, makes it feel a bit more enclosed and sheltered for the birds.

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An chough nest-box facing the sea (the black dot in the sea is a seal, trust me)

One factor Tony did not consider when first designing these boxes was how badger-proof they would need to be. Don’t be alarmed, Welsh badgers have not adapted to have opposable thumbs and learn rope skills. They do, however, burrow and at one particular sight they have given the nest-box a bit of a battering pushing it out of place.

One nest-box needs re-positioning after a run in with badgers.

The boxes need to be checked each year as they do suffer from being exposed to the sea air. As long as the roof remains dry and there is no risk of collapse the boxes can be used for several years. It normally takes a year before a breeding pair move in to a new box. Lots of HSE forms to fill in, quality control tests, and the long wait for the Royal Court date (Jersey in-joke sorry).

It is clear that the work Tony and his colleagues are doing has made a great difference to the Welsh chough population. Jersey’s choughs may well benefit from the same practices as these birds have no experience of wild nest sites and will need some encouragement.

Choughs in South Stack, Anglesey

Choughs at South Stack, Anglesey

Many thanks once again to Tony for taking time out. You can find out more about his work at www.ecologymatters.co.uk

A murder of crows?

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Carrion crow (2). Photo by Mick DrydenFrom British Ornithologists’ Union

They steal, raid nests, and keep the company of witches. But the unpopular crow may not be the menace people think.

A new study, published in the BOU’s journal IBIS (here), has found that crows – along with their cousins the magpie and the raven – have surprisingly little impact on the abundance of other bird species.

Collectively known as corvids (a group that includes choughs, jackdaws and even jays), these birds are in fact being menaced by mankind in the mistaken belief that removing them is good for conservation. This new study found that in the vast majority of cases (82%), corvids had no impact at all on their potential prey species.

Magpie. Photo by Mick Dryden“Many nature lovers have been distressed to witness a crow or magpie raiding the nests of their beloved garden songbirds, stealing their eggs or eating their defenceless chicks,” said study co-author Dr Arjun Amar from the Percy FitzPatrick Institute for Ornithology. “Although this predation is entirely natural, these observations can be upsetting to witness and often leave people wondering if these predators might be reducing bird numbers.”

“However, our global review suggests that we should be cautious before jumping to conclusions over the impacts these species may have. Just because a predator eats something occasionally does not always mean that they have an impact,” Dr Amar said.

The study reviewed all published evidence on whether predation by corvids actually reduces the overall breeding performance of birds or, more importantly from a conservation perspective, reduces their numbers. Data were collated from 42 studies of corvid predation conducted across the globe over the last 60 years.

Not only were corvids unlikely to have any impact on their potential prey species, if there was an impact it most often affected the breeding success of the prey species rather than their subsequent numbers. Half of cases found that corvids reduced breeding success whereas less than 10% of cases found that they reduced prey numbers in the long term.

Raven (3). Photo by Mick Dryden“These results have big implications for the likely benefits of corvid control,” Dr Amar said. “They suggest that killing corvids will be of most benefit to those interested in gamebird shooting rather than conservationists.” He added: “Bird hunters are usually most interested in increasing numbers of birds available to shoot immediately after the breeding season and this appears to be where corvids have most impact”. “Conservationists on the other hand, are usually interested in increasing a species population size and our results suggest that only in a very few cases did corvids have an influence on this aspect of their prey,” Dr Amar said.

The review analysed the impact of six corvid species on a variety of prey species including gamebirds, songbirds, waders, herons, cranes, sea birds, wildfowl and raptors. The 42 studies incorporated into the review included 326 cases of corvid – bird prey interaction Most of the data stemmed from field research in the UK, France and the United States. The impacts were determined partly by comparing bird counts before and after corvids were either removed or their numbers reduced.

The review also found large differences between the impacts of crows, historically considered the most ‘cunning’ corvid, and magpies which are sometimes killed by home owners hoping to protect songbirds in their gardens. Crow species were six times more likely to have an impact on bird prey species than Magpies.

Magpie (2). Photo by Mick Dryden

Mistaken assumptions about corvid predation were possibly explained by the birds’ diurnal nature and the fact that they are conspicuous nest predators: “Their importance in prey population regulation is often assumed prior to any assessment of the evidence,” the study warned.

Chrissie Madden, the lead author on the paper, hoped that the review would challenge the perception that all corvids were bad, thereby preventing needless killing: “Our results suggest that this is a mistaken belief and that generally speaking people would be wasting their time killing corvids to increase bird numbers”.

“Overall therefore, our study points to the fact that we are often too quick to jump to the conclusion that crows and magpies may be the cause of bird population declines,” she said.

You can download A review of the impacts of corvids on bird productivity and abundance here

Wind turbine warning for wildlife

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Urbine221dcFrom University of Stirling

Careful planning measures must be put into place to ensure small wind turbine developments (such as those that fit on house roofs or in the garden) do not cause bat and bird population decline, according to research from University of Stirling.

Small domestic wind turbines or ‘microturbines’, which can kill bats and birds, are becoming an increasingly popular means to generate clean energy for home owners.

The Stirling team, whose research was published in Biodiversity and Conservation, found that the careful positioning of these turbines – and the avoidance of installing them in areas where bird or bat activity is likely to be high – is vital to ensure rare species of wildlife are not forced to abandon their homes in search of safer habitats.

Although previous research has shown that birds and bats may be killed in significant numbers by colliding with turbines in large wind farms, the Stirling research – carried out in collaboration with the British Trust for Ornithology – is the first study to examine whether small wind turbines could have a similar impact on wildlife.

The study looked at data, questionnaires from turbine owners and computer modelling, to assess the likely levels of bird and bat deaths caused by all small wind turbines across the UK. Results showed that between 1,567–5,510 birds and 161–3,363 bats may be killed per year by small wind turbines in the UK.

Dr Jeroen Minderman from the University’s School of Natural Sciences said: “Bird and bat deaths are a reality at small wind turbine sites.

“Whilst our findings show the relative extent of this problem is much smaller than other causes of wildlife deaths, such as cats or road collisions, our previous work has shown that bats avoid microturbine development areas – which may explain the relatively lower number of bat deaths estimated.”

Dr Kirsty Park, who led the Stirling research team said: “While our estimates of bird and bat deaths may seem high, it is important to realise that this is across a range of species and across more than 19,000 small wind turbines currently installed in the UK. Moreover, such estimates are several orders of magnitude lower than estimated numbers of deaths due to other human-related causes.

“However, this avoidance of microturbine sites by wildlife might have an adverse impact on rare or sensitive species if it causes bats to abandon what would otherwise be suitable feeding areas.”

She stressed: “Appropriate siting decisions that avoid such effects are therefore very important, and our work can help inform this.”

Microturbines are much smaller than their large wind farm counterparts and used mainly in domestic and farmland settings. Normally they are installed individually and can make a substantial contribution to household energy needs.

The increase in installation of such turbines is due to rapid technological developments and the introduction of financial incentives in the form of feed-in tariffs: schemes which pay people for creating their own ‘green’ electricity and offer additional bonuses for exporting electricity into the grid.

Abstract of the paper Estimates and correlates of bird and bat mortality at small wind turbine sites can be read here

Research published by the Stirling team in 2012 (full paper here) suggested that, while further research was needed, turbines should be sited at least 20 metres away from potentially valuable bat habitat. This will help to maximise the benefits of renewable energy generation whilst minimising potentially adverse effects on wildlife.

Recommendations for siting small turbines can be seen at Bat Conservation Trust, Scottish Natural Heritage and Cornwall Wildlife Trust 

Permissions etc. to install a turbine in Jersey can be read here