Two fields with winter bird crops planted out by Steven Baudains from J&S Growers near Les Landes, are, at the end of February, still filling up with birds that are probably now coming from other conservation sites on the Island, where the fields have already been ploughed. Since January the numbers of birds in the Les Landes fields have increased from average flock counts of around 100 birds to 400-600 birds. Most of the birds are chaffinches, with many linnets and reed buntings, goldfinches, greenfinches, and even the odd brambling. There are also lots of meadow pipits and stock doves, and raptors such as sparrowhawks, marsh harriers and even a common buzzard, an uncommon sight in the north-west, keeping an eye on them.
And just to confirm our suspicion that the birds are flocking in from other areas in Jersey no longer suitable, we ‘re-trapped’ a reed bunting caught first in the reedbeds at St Ouen’s Pond, where the buntings roost up for the night. This male bunting was re-trapped earlier this winter in conservation fields with bird-crops immediately behind the Pond, where good numbers of reed buntings have been counted this winter.
The most interesting bit is that, as those fields by the pond were ploughed during the first week of February, this bird and probably others have found their way to the fields at Les Landes, which is where it was re-trapped again on the 15th of February.
So much information carried by such a tiny thing! A great example too of the valuable data that can be gathered through ringing birds like this bunting. The bunting further shows the importance of having a network of conservation fields that can support the birds in this ‘hungry gap’ when many of the fields that they have needed to survive begin to get ploughed up.
Thanks again to the many farmers involved in this project for planting out all those fields. Without this effort birds like this reed bunting and the brambling would have gone hungry this winter.
Recently we saw how our partial migrant birds are changing their habits and no longer migrating down to the Mediterranean (here). Now, research by the BTO using detailed distribution maps of 122 species of bird further measures the ways that climate change could be affecting our local bird populations. Species distribution was found to be changing, but the range shifts detected could not be explained by any single climatic factor, indicating that the distribution changes for British birds are complex, multi-directional and species specific.
The BTO drew from breeding bird atlases developed two decades apart. Atlas data are collected in a standardised manner by thousands of volunteer bird surveyors, providing a unique barometer of the impacts of environmental change on this one component of British biodiversity.
From the early 1980s to the early 2000s, temperatures in spring and summer increased, which should have pushed some bird species to the northwest if this aspect of climate is key to their success, whilst higher temperatures in winter should have pushed them to the north and northeast. In contrast, if spring rainfall is critical to species, they should have been pushed to the west. Analyses looking at how bird distributions had actually changed over this period found that birds had indeed shifted to the north, on average by 13.5 km, which continued a trend seen in previous decades. However, more than a quarter of the species had also extended their ranges to the northwest and northeast, while almost half had retreated from southerly directions. The ranges of a few species such as greylag goose and great tit had extended in all directions while others like lesser spotted woodpecker and corn bunting had retreated from all directions. Overall the range shifts could not be explained by any single climatic factor, indicating that the distribution changes for British birds are complex, multi-directional and species specific.
Another report published this month from Sweden shows that short distance migrants to this country had advanced their arrival to southern Sweden more over time than long-distance migrants. However, no such difference between long- and short-distance migrants could be seen in central Sweden suggesting that short distance migrants were either arriving in the south much earlier or even spending the winter there before moving further north. In long-distance migrants, the difference in first arrival between the historical and present-day dataset did not differ between southern and central Sweden. These results further establish that many short-distance migrants are becoming resident further north or shortening their migratory route, possibly due to climate change enabling more northerly wintering areas.According to annual first observation used in this study, this seems to be especially true for chaffinch, whooper swan, starling, and woodcock.
It is clear from this research that many of our birds are undergoing big changes in their patterns of migration and selection of wintering areas. A further change, the impact that the number of arriving species, like the egrets, new to particular areas will have on existing biodiversity is, however, not yet clear. As some of our bird species are not shifting their ranges as fast as others, or aren’t moving in the same direction, our bird communities of the future could be very different from those we know today. There is still much to learn if we are to manage the impacts of anthropogenic climate change on our wildlife, and studies such as these will help policymakers to adopt conservation and land management strategies that effectively assist species survival.
You can see the reports here:
Directionality of recent bird distribution shifts and climate change in Great Britain. Read abstract here
Change in spring arrival of migratory birds under an era of climate change, Swedish data from the last 140 years. Download paper here
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.
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 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 showing 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 recorded 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.
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.
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.
Results 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.
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 Mediterranean. 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.
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.
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
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 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.’
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.
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.
“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.
“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.
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 abundancehere
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.
Further 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.
Providing 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.
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. The 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.
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.
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.
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.
Read Graham McElwaine’s blog on monitoring brent geese from their breeding grounds (watch out for those polar bears), to the winter beaches here.
By Cris Sellarés
And just to confirm our suspicion that the birds are flocking in from other areas in Jersey no longer suitable, we ‘re-trapped’ a reed bunting caught first in the reedbeds at St Ouen’s Pond, where the buntings roost up for the night. This male bunting was re-trapped earlier this winter in conservation fields with bird-crops immediately behind the Pond, where good numbers of reed buntings have been counted this winter.
