Category Archives: Bird monitoring

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

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 

Hedges in farmland: good for birds, good for farmers!

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Kestrel (2). Photo by Mick DrydenFurther evidence of the importance to birds and farmers of hedges in agricultural land comes to us from a rather unlikely source. Studies from Akot, Maharashtra State in central India revealed how strong the difference in bird numbers and diversity between different farmland sites with and without hedges can be. Hedges in the study area were shown to provide important nesting, feeding and sheltering sites for birds in agricultural areas with highest numbers of birds in those fields with hedges.

During the Indian study, 64 bird species from 34 families were observed. Most of the birds were recorded actually in or very near hedges. An earlier study (here) in Germany reported that increasing hedge length enhanced significantly the number of bird species and that adding hedges or introducing organic farming practices should be primarily promoted in simple landscapes, where it really makes a difference for biodiversity.

These studies show that hedge length has a stronger effect on bird richness than management and that the increasing length of hedges enhances birds in conventional, non-organic, fields too. Bird conservation even in intensively used agricultural landscapes should concentrate on hedges or green lanes.

OLYMPUS DIGITAL CAMERAProviding more hedgerows and carefully managing them, can significantly contribute to the conservation of declining farmland birds. Birds forage in the agricultural fields, using the hedges for resting and breeding. Highest diversity of birds was also directly connected to diversity of plants as the greatest number of plant types gave more choice of food for the bird species. High numbers of bushes and plants at the boundary of agricultural land will benefit the largest numbers of birds. Thus planting trees in agricultural lands and well managed hedges can increase the bird diversity and large scale cutting of hedges should be avoided.

Not only will populations of birds benefit from increased hedges but the birds can themselves benefit the farmer. Insectivorous and predatory birds play a very useful role in controlling insect and rodent pests of crops. Presence of healthy numbers of birds in the farm fields is an eco-friendly and useful way of controlling the pests on the crop so, hedgerows must be saved to conserve farmland bird diversity. Hedges should, however, be maintained properly and not allowed to become invasive and reduce the utilizable area of the field.

Studies on farmland avian diversity with special reference to importance of hedges in conserving farmland bird diversity can be downloaded here.

Chaffinch (5). Photo by Mick Dryden

Brent geese – VIP guests in the Channel Islands

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Brent geese (6). Photo by Mick Dryden

Birds On The Edge and Graham McElwaine of the Irish Brent Goose Research Group

Brent geese must be amongst the best known birds in the Channel Islands. Up to 1,500 may winter in Jersey with smaller numbers in Guernsey, Herm and Alderney each year. - 051The main reason that these geese come to our shores is because there are beds of the highly vulnerable eel-grass, one of the birds’ most important food sources here. However, despite spending around eight months with us, how much do we really know about these little, approachable geese? For one thing, how many Channel Islanders actually know that our islands are almost unique in annually hosting populations of two very distinctly different brent geese?

Dark-bellied brent geese (Branta bernicla bernicla) return to us each year in September from the Russian arctic. They breed up in the wilds of the Asian tundra but spend their winter in much tamer environments of British and French beaches, harbours and, at times, farmers’ fields and even golf courses. It is often hard to imagine that the calm little geese we see in winter are the same birds that disperse across a hostile arctic wilderness each spring.

Brent geese (12). Photo by Mick Dryden

Earlier in the 20th Century, dark-bellied brent geese were quiet rare. The numbers we see now (over 200,000 worldwide) are testament to a successful global conservation campaign. The population began to rise when UK and France banned hunting in 1954 and 1966 respectively. However, things really changed when the flocks migrating through Denmark were given legal protection in 1972. Safe in their breeding grounds, their wintering areas and on their migration stopovers in between, this endearing little goose quickly recovered.

In winter, we see these Russian visitors collecting in our quiet bays and beaches or flocking inland on the high tide in a handful of places (most still roost out to sea). Over recent years, many geese have been given coloured plastic rings by researchers that are easy for birdwatchers to see allowing us to keep an eye on the birds’ activities. These ringing studies, some geese have been caught locally, some in the Netherlands and some in the arctic, show us how long the birds might live, how productive their breeding seasons are (did you know their breeding success is linked to the abundance of lemmings?) and, most importantly, how they distribute themselves along our coastline. Perhaps the most important discovery has been that individual geese return to the same bay or stretch of beach each year and don’t visit other bays. This means that loss of one site might mean the total loss of that site’s geese. They won’t just go to another bay. Put simply, they’ll probably die.

Pale-bellied brent geese (Branta bernicla hrota), the other brent goose present in the Channel Islands over the winter, arrive rather later, in November each year, and are much less numerous. These, as their name suggests, and as can be seen in the photographs, have much paler bellies than their Russian counterparts. Juvenile upper-wings have a barred appearance when the bird is at rest, compared with the more uniform back of adults. Up to 150 can be observed in Jersey, concentrated in St. Aubin’s Bay (look out for them at West Park or by St Aubin’s Harbour), but only a handful has been recorded in the other islands.

Brent geese (9). Photo by Mick Dryden

Similar ringing studies to those for the dark-bellied brent geese have shown that there are two distinct flyway populations of pale-bellied brent geese, one which breeds in Svalbard and North-eastern Greenland, the other in arctic Canada. The latter population, to which our birds have been shown to belong, currently numbers around 40,000 birds, and has been subject to intensive study by the Irish Brent Goose Research Group and their Icelandic collaborators. When they arrive in Jersey, the geese have undertaken an amazing annual migration, travelling from the breeding grounds over the Greenland Ice-cap, then staging in western Iceland before an onward flight to Ireland, where an amazing 75% of birds gather initially at a single site, Strangford Lough in Northern Ireland. Peak numbers generally occur there in early October, following which the geese move on, as the eel-grass which attracts them there gets depleted. About 90% of these pale-bellied brent geese will disperse to within the bays all around Ireland for the rest of the winter, but others will travel further, to spend the rest of the winter in Western Britain, Normandy, and here in Jersey. Jersey is, therefore, particularly special as it is near the southern limit of the flyway range, as shown by the re-sighting of marked birds.

The resightings of the pale-bellieds further demonstrate just how site-faithful these geese can be. An example is 3XYY (see photo), which was ringed near Reykjavik in Iceland in May 2006 and has appeared at St. Aubin’s Bay every winter since then. Another is PUWR, seen every winter but one since being ringed in west Iceland in May 2010, passing through Jersey en route to Régnéville in Normandy.

Both these geese are back this winter.

Brent geese (8). Photo by Mick Dryden

Whilst the numbers of geese in this population have approximately doubled over the past 10-15 years, they can experience low reproduction in years when conditions in the arctic are inclement, as the suitable weather window of time for successful breeding can be very narrow. This was particularly evident after summer 2013, when birds returned to the wintering areas with virtually no young. Birds are highly dispersed whilst breeding, and nests are liable to predation. Brent geese tend to congregate, often in very large flocks, during passage and the winter. The fact that such a high proportion of the flyway population gathers together at a single site in autumn also renders the geese potentially significantly vulnerable to a major problem with their main food source there (eel-grass), and to contagious disease. This year again, very few young birds have been seen in Jersey while, in contrast, the dark-bellied birds appear to have had a very good year.

So, next time you see a flock of this most maritime species of goose, take a good look and see whether you can spot any of these amazing little pale-bellied brent geese, and marvel.

Interestingly, to complete the record, a third brent goose, the black brant (Branta bernicla nigricans) lives in the Pacific. This goose too occasionally, but not annually, visits the Channel Islands usually in the flocks of dark-bellied brent, presumably having joined them in the Russian far east.

Brent geese (11). Photo by Mick Dryden

Read Graham McElwaine’s blog on monitoring brent geese from their breeding grounds (watch out for those polar bears), to the winter beaches here.

 

 

Reporting Jersey seabird casualties

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Ouaisne dead bird count 05 Tim RansomMany thousands of seabirds including grebes, divers, ducks, auks, gulls, cormorants and shags spend the winter at sea in the Channel Islands. Even in a good year it is possible that some of these birds may be found dead on our coastline. However, in periods of extremely bad weather or during pollution incidents many hundreds of birds may wash up on the beaches.

Earlier this year over 1,000 dead birds were found on our beaches following a period of extreme weather in the area. In 2013 we had the tragic experience of PIBs being discharged in the Channel and killing many seabirds.

HW1The sight of dead birds like these is never pleasant but it is very important that we record the numbers of birds and their species in order to understand the extent of the incident and to predict what impacts there may be on already threatened seabird populations.

The birds may have rings or other identification devices and reporting these will increase our knowledge of the birds’ ecology as we can map where different species spend the winter or chose to moult and understand how long they can live.

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If you find a dead seabird please report it immediately to Birds On The Edge at birdsote@gmail.com or phone Glyn Young at 01534 860032 or Cris Sellarés at 07700 337077 with the following important information:

1)The species of bird or size, colour of the head, body, beak and feet if species is unknown;

2) The date that you found the bird and your contact details if you are happy to share them;

Puffin. 22 February 2014. Photo by Harriet Whitford3)  Information on its location (e.g. which beach and nearest landmark such as slipway or café);

4)  A picture taken from your phone or camera, if you can;

5)  Any rings or other tags that it might have. If ringed, please write down the ring number and address.

This information can also be downloaded here

Thank you for your assistance.                                 

Gulls switching from fish to chips

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Glaucous-winged gull in Canada. Photo by Mick DrydenFrom New Scientist

Gulls tucking in to discarded food or flocking around landfills has become a familiar sight. Now data from the Pacific north-west of Canada spanning 149 years has shown that substituting fish with less nutritious food is linked to population declines and lower fertility in glaucous-winged gulls (Larus glaucescens) a close relative of the herring and lesser black-backed gull.

Louise Blight from the University of British Columbia and her colleagues looked at 270 gulls’ feather samples from museums, taken between 1860 and 2009. Using the ratios of heavy isotopes of carbon and nitrogen, the team pieced together the dietary habits of these seabirds, all of which had lived in the Salish Sea region off the coast of south-western Canada and the north-western USA.

They found a decline in heavier carbon isotopes, indicating that the gulls shifted from a fishy source of carbon to a terrestrial source. A decline in heavier nitrogen isotopes implied that their diets had also shifted to a less nutritious staple; most likely lower marine invertebrates and corn-based organic food waste.

This change in diet coincided with over-fishing in the region in the early 1900s, after which the gull population dropped.

“The stable isotope work shows a decrease of fish in diet over the time frame where forage fishes have declined”, says Blight.

Fish or chips

Overfishing has meant that one of the gulls’ favourite fish species, the highly nutritious eulachon (a smelt species), is now considered threatened in the Salish Sea area. Another former staple, the Pacific herring, no longer forms the large aggregations that gulls once feasted on.

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But between 1960 and 1986, the gull population increased, perhaps because more readily available rubbish, although less nutritious than fish, was helping to support the population. “Our field observations show that many pairs are feeding their chicks on sand lance and herring, and that some pairs feed their chicks on things like chicken or French fries,” says Blight.

This shift to a poor-quality, low-protein diet could be linked to reduced reproductive success in the gulls. A previous study by Blight showed that gulls have been producing smaller and fewer eggs over the last few decades, which she believes is consistent with a decline in diet quality around egg production time in the early spring.

“Rarely will you visit these garbage dumps without seeing multiple gull species. You will even see them at transfer stations or intermediate garbage staging areas,” says Joe Gaydos, Director and Chief Scientist at the SeaDoc Society, a Salish Sea research organisation based in Eastsound, Washington.

Chouet Landfill. Guernsey. Photo by Paul Veron (2)

The glaucous-winged gull is a generalist feeder, meaning it can survive on a wide range of different food sources. While there is some evidence that switching to a trashy diet has helped gulls through tough times, overall, the data reveals a worrying decline in numbers. “Their populations should not decline as quickly as specialist feeders. The fact that generalists like gulls could be in decline is definitely worrisome,” says Gaydos.

This research will be published in Global Change Biology and the abstract can be read here

Paul Veron heads a Guernsey-based project (website and Birds On The Edge report) looking at long-term ecology of gulls in the Channel Islands. Paul is particularly looking at what will happen when the Chouet Landfill site is closed and the gulls across our Islands lose access to a major part of their food supply now that there are so few fish available to them.

Jersey crapaud is newly-understood species unique in the British Isles

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Bufo spinosus male2 JWWBy John Wilkinson

Background

CharingXCrapaud2The Jersey toad or crapaud has long been associated with the Island and Jersey Islanders – Jersey is the only one of the Channel Islands with any species of toad. Decades have passed, however, since toads have been present in “scarce credible” numbers “crawling over the rocks like an army” (as quoted by Frances Le Sueur).

In 2004, while with the Durrell Institute of Conservation and Ecology (DICE), University of Kent, I began a three-year PhD study on Jersey toads, investigating their ecology, populations and genetics – as well as anything else that might account for observed reductions in numbers on the Island. I found that they behaved very differently to toads in England and parts of France, breeding much earlier and using different (much smaller) ponds on average. A central reason for the toads’ decline in Jersey has probably been the shift away from traditional agricultural reservoirs to mobile stock watering tanks, coupled with the fact that demands on the Island’s water supply are heavier so any ponds dry up more quickly in the summer. Jersey toads are now almost completely dependent on Islanders’ garden ponds and occur mainly in parts of Jersey where people have suitable clusters of ornamental ponds in which they can breed. This also makes them Le Marquand tadpolessusceptible to road mortality and isolation from nearby populations when new developments occur and/or roads are constructed.

I now work for the GB charity Amphibian and Reptile Conservation (ARC) but return to Jersey as often as I can to carry out training for the National Amphibian and Reptile Recording Scheme (NARRS). After one such trip, I had an opportunity to find out more about the strange habits of the crapaud….

Uniquely Jersey

I was asked by an old colleague if I had any genetic samples from Jersey as a new species of toad (Bufo spinosus) had been described that was found in parts of nearby France as far north as the Contentin Peninsula. With no expectation of anything other than contributing to an ongoing study, I sent off some “old” genetic samples from my PhD research to Pim Arntzen at the Naturalis Institute in the Netherlands, where much work on the conservation genetics of European amphibians is carried out…. Some while later, the news arrived that the samples had proved “interesting” and that a morphological study was needed to establish what species the Jersey crapaud really was! So, in Spring 2013, I returned to Jersey and, with the help of Department of the Environment staff, took measurements of toads from various parts of the Island…. all on the day before the dramatic snowfalls of that year that Islanders will certainly remember. Those morphological data were also sent to Naturalis and analysed along with data from the earlier DNA.

Jersey crapaud. Bufo spinosus from Les Landes, Jersey. Photo by John Wilkinson

Herp joournal front coverFast forward to October 2014 and Pim, mine and colleagues’ paper revealing the Jersey crapaud as a new species for the British Isles was published in the Herpetological Journal. Toads in Jersey are indeed Bufo spinosus, a species that split from the usual “common” toad (Bufo bufo) some nine million years ago with the rising of the Pyrenees. The species evolved in Iberia and has since spread south into North Africa and north through Western France as far as Jersey – but nowhere else in the British Isles. So Jersey toads share more of their history with toads from Algeria and Spain than they do with English toads!

Bufo spinosus grows bigger than B. bufo, irrespective of latitude, and has evolved to take advantage of smaller ponds that dry out over summer (as are found in Iberia, for example) in dryer, often open habitats. B. bufo prefers large, deep permanent lakes and woodland areas. So when toads arrived in prehistoric Jersey and encountered dune slacks and maritime heaths, they would probably have been perfectly at home. Only recently have larger water bodies such as reservoirs become much of a feature in the Jersey landscape.

The ability of Jersey’s B. spinosus to adapt to smaller breeding ponds and open landscapes has probably been a factor in allowing them to use Islanders’ ornamental ponds for breeding. Armed with this new knowledge, we can better make decisions to help conserve the crapaud in Jersey and ensure that it is still around to be associated with many more generations of Jerseymen!

Download the paper A new vertebrate species native to the British Isles: Bufo spinosus Daudin, 1803 in Jersey here

Common birds continue to decline while rarer birds increase

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House sparrow (2). Photo by Mick DrydenFrom Phys.org

A new study has shown that, as is widely known to readers here, bird populations across Europe have experienced sharp declines over the past 30 years, with the Common starling (2). Photo by Mick Drydenmajority of losses from the most common species. However, what is less well known is that numbers of some less common birds have risen. The study, published in the journal Ecology Letters, reveals a decrease of 421 million individual birds over 30 years. Around 90% of these losses were from the 36 most common and widespread species, including house sparrow, skylark, grey partridge and starling, highlighting the need for greater efforts to halt the continent-wide declines of our most familiar countryside birds.

One of the study’s authors, Richard Inger from the University of Exeter, said: “It is very worrying that the most common species of bird are declining rapidly because it is this group of birds that people benefit from the most.”

Blackbird (2). Photo by Mick Dryden“It is becoming increasingly clear that interaction with the natural world and wildlife is central to human wellbeing and significant loss of common birds could be quite detrimental to human society.”

Birds provide multiple benefits to society. They help to control agricultural pests, are important dispersers of seeds, and scavenging species play a key role in the removal of carcasses from the environment. In addition, for many people birds are the primary way in which they interact with wildlife, through listening to bird song, enjoying the sight of birds in their local environment, feeding garden birds and through the hobby of bird watching.

The majority of the declines can be attributed to considerable losses from relatively few common birds, but not all common species are declining. Numbers of great tit, robin, blue tit and blackbird were all shown to be increasing. Populations of rarer species, including marsh harrier, raven, common buzzard and stone curlew have also shown increases in recent years: this is likely to be the result of direct conservation action and legal protection in Europe.

Marsh harrier 4. Photo by Mick Dryden

Head of Species Monitoring and Research at the RSPB’s Centre for Conservation Science Richard Gregory said: “The rarer birds in this study, whose populations are increasing, have benefited from protection across Europe. For example, white stork and marsh harrier receive among the highest level of protection in the EU – this is why their numbers have increased. The conservation and legal protection of all birds and their habitats in tandem are essential to reverse declines.

“This is a warning from birds throughout Europe. It is clear that the way we are managing the environment is unsustainable for many of our most familiar species.”

Conservation efforts tend to be focused on rarer species but the research suggests that conservationists should also address issues affecting common birds, for example those traditionally associated with farmland. The decline in bird populations can be linked to modern farming methods, deterioration of the quality of the environment and habitat fragmentation, although the relative importance of these pressures remains unclear.

Reed bunting. Photo by Romano da Costa.This pattern has been highlighted in Jersey where the very high profile gains like the newly arrived marsh harrier, common buzzard and little egret, and returning species like peregrine and sparrowhawk, are offset by the losses like yellowhammer, reed bunting and cuckoo and declines in many others including stonechat, linnet and skylark.

The study brought together data on 144 species of European bird from many thousands of individual surveys in 25 different countries, highlighting the value of the different national monitoring schemes increasingly working together. The researchers suggest that greater conservation funding and effort should be directed to wider scale environmental improvement programmes. These could include urban green space projects, and effective agri-environment schemes, which, informed by lessons learned from past schemes, should aim to deliver real outcomes for declining bird species whether they are rare or common.

Read the paper’s abstract here

Jersey choughs stretch their wings

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Well, it had to happen. After staying patiently around the release aviary at Sorel for several months, the choughs have begun to explore the Island’s coastline. On Monday (27th October) we received the first reports of choughs away from the north coast. At first slightly sceptical, it quickly became obvious that all 16 birds had left to do some exploring. It also, very quickly, became apparent that the birds were not all together.

The 10 young birds (all reared this year) had gone down to the Island’s south-west, to cliff sites where choughs once bred. The chough team had recorded all the birds at Devil’s Hole shortly after dawn so were surprised to hear that they were now several miles away. The older six birds had also gone on an expedition but only got about half way along St Ouen’s Bay before heading home. The team caught up with the very settled young birds and watched them head north again in time for lunch! All the birds remained at Sorel throughout the afternoon and roosted there.

OLYMPUS DIGITAL CAMERACome Tuesday, we were interested to see what would happen. The 10 flew south again and were tracked quickly. Again they flew home for lunch. On Wednesday we lay in wait for them, watched them leave the north coast and saw them arrive in the south-west. We also timed them leaving and arriving back ‘home’ for their lunch. The pattern seemed set and we have a good idea of the route they were taking and the landmarks they were using. The commuting flights were taking around 15 minutes although an impressive 11 minutes was recorded on Thursday.

While the younger birds were roaming a little like a gang of teenagers the older birds were pretty well staying put. Except for a brief wander west along the north coast. The pattern seemed set. Until Sunday, when, in heavy early morning rain, no one moved! It will be interesting to see what happens next. We wondered exactly how the 10 found the traditional sites in the south-west when, thanks to the team, we knew roughly where the birds were each day and couldn’t see when they had had time to find the new spots. Then, we thought, if they soar (as they often do) above Sorel they can see all the Jersey coastline. Is that how they knew where to go? It makes sense too when you realise that the commuting flights are direct and not following the coastline.

We received several very important sightings of the birds during the week and would not have put the whole story together without them. We are grateful to everyone who sent in sightings through the website, by phone or through social media. The wanderings are, no doubt, going to increase from now on so please carry on with the sightings. Even with transmitters on the younger birds we can lose track of them if they are moving fast. Your sightings can help us piece together the birds’ activities and the routes taken. You can use the webpage here, through the Birds On The Edge email address birdsote@gmail.com, social media, directly to the team or through Jersey Birds.

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