wintering farmland birds · 1999) may have altered the range and abun-dance of farmland birds in...

Farmland birds have been headline news inboth the popular and scientific pressrecently as a result of marked population

declines, especially since the mid 1970s. Con-certed scientific work and lobbying haveresulted in several species being identified as‘Species of Conservation Concern’ (Gregory etal. 2002) and the inclusion of wild bird popula-

tion trends as one of the 15 headline indicatorsin the Government’s ‘Indicators of SustainableDevelopment’ (DETR 1998). In order for theGovernment to achieve their pledge of reversingfarmland bird declines by 2020, we require con-tinually updated knowledge of the status andecology of farmland birds and monitoring ofmanagement schemes (Chamberlain & Vickery

118 © British Birds 97 • March 2004 • 118-129

ABSTRACT Farmland in winter is an important habitat for a wide variety ofresident and migratory birds. Many farmland species have declined in recentyears, and knowledge of their winter ecology and distribution is vital beforeproviding recommendations for management practices designed to reversethese declines.Two surveys organised by the BTO and British Birds – Casual

Records and Winter Walks – aimed to draw on the local knowledge andenthusiasm of birdwatchers to assess the abundance, distribution and

habitat use of farmland birds in winter.This paper reports some of the early findings from these surveys.

Wintering farmland birds:results from mass-

participation surveys Simon Gillings and Peter Beaven

Fieldfare Turdus pilaris - Simon Gillings

2002). This is particularly true for the winterperiod, since poor winter survival is implicatedin the declines of many species (Siriwardena etal. 2000). Furthermore, wintering in poor-quality habitat may affect subsequent breedingsuccess (e.g. Marra et al. 1998).

The last time wintering birds were surveyedacross a wide geographic area was for theBTO/Irish Wildbird Conservancy Winter Atlasin the early 1980s (Lack 1986). Since then,changes in farming (Chamberlain et al. 2000;Vickery et al. 2001; Robinson & Sutherland2002), continuing population declines (Fuller2000) and changing winter weather (Hulme1999) may have altered the range and abun-dance of farmland birds in winter, at the sametime altering patterns of habitat use. Againstthis background, the BTO, in partnership withJNCC, began the Winter Farmland Bird Survey(WFBS), a three-year (1999/00-2001/02) volun-teer survey of a suite of common,declining or scarce farmland birdspecies. The aims of WFBS wereto assess national, regional andseasonal patterns of distribution,abundance and habitat selectionacross a large geographic area anda number of consecutive winters.

The core part of WFBS was adetailed survey of 1-km squaresrandomly located throughoutlowland agricultural areas ofBritain. Some species are,however, likely to be so scarce thatrandom squares will provide fewrecords. For example, Tree Spar-rows Passer montanus and CornBuntings Emberiza calandra arenow so scarce that they regularlyfeature on local birdlines. Yet thisalso implies that birdwatchersknow where these species stillpersist. The random squaresurvey was supplemented by twomass-participation volunteersurveys, aimed at tapping theenthusiasm and knowledge ofamateur birdwatchers: CasualRecords was designed to amass alarge quantity of information onthe numbers and distribution of‘significant’ flocks of farmlandbirds, and Winter Walks involvedvisiting a standard area regularly

and recording the presence or absence ofspecies. This paper presents the results of theCasual Records and Winter Walks surveys, con-centrating on five of the 30 target species. Theseinclude a gamebird (Grey Partridge Perdixperdix), a wader (Northern Lapwing Vanellusvanellus, hereafter ‘Lapwing’), a migratorythrush (Fieldfare Turdus pilaris) and twogranivorous passerines, one still relatively wide-spread (Sky Lark Alauda arvensis) and the otherscarce (Tree Sparrow).

MethodsForms for Winter Walks and Casual Recordswere circulated to BTO members and BritishBirds subscribers in the autumns of 1999, 2000and 2001. The field methods were simple. ForWinter Walks, observers chose a route at least 1 km in length through farmland and visited itregularly between November and February. On

119British Birds 97 • March 2004 • 118-129

Wintering farmland birds

64. Grey Partridges Perdix perdix were reported chiefly from centraland eastern parts of England during the surveys described here, with

few records from Wales or Scotland.

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Table 1. Summary of uptake and reporting of farmland birds from Casual Records and Winter Walkssurveys in the three winters of coverage.

1999/00 2000/01 2001/02

Casual RecordsForms received 440 302 280Flocks recorded 7,301 4,860 5,353Total birds counted 1,238,477 852,530 893,045

Winter WalksRoutes visited 447 275 303Flocks recorded 21,810 13,688 15,990Total birds counted 554,861 351,240 395,686

Fig. 1. Maps showing the distribution of (a) relative density of BTO members; (b) 10-km squares containing Winter Walks routes visited in at least one of the three winters; (c) 10-km squares from which Casual Records

were received in at least one of the three winters; (d) the distribution of arable crops and grassland from MAFF June agricultural census returns. On (a) and (d), increasing dot size indicates greater BTO member

density and farmland area respectively.

(a) (b)

(d)(c)

each visit they noted the date and the number,activity and habitats used for 30 target species.Casual Records forms were used to record ‘sig-nificant flocks’ of the target species from any-where in the country, with guidance as to whatconstituted a significant flock, e.g. 100 or morethrushes.

Data from the two surveys were used toderive distribution maps, flock sizes, reportingrates and measures of habitat use. By dividingall visits into weeks, from 1st November to28th/29th February, it was possible to deriveweekly reporting rates; these are simply theweekly percentage of Winter Walks routes onwhich a species was seen. They were producedto determine seasonal patterns of occurrence onfarmland, and can be compared with weeklyreporting rates for farmland species in gardens(see below). Habitat descriptions provided byobservers were used to classify every flock intodifferent categories such as crop types, stubbles,hedgerow, farmyards. Note that because nomeasures of habitat availability were taken, wecannot consider habitat preference, only habitatuse. For some analyses, data were amalgamatedinto regions (see fig. 1). These comprised Walesand Scotland plus three English regions basedon those used by the Department for Environ-ment, Food and Rural Affairs (Defra).

The BTO/CJ Garden BirdWatch survey pro-vides the only other means of assessing seasonaloccurrence of birds in winter. This involves weeklyrecords of bird species occurrences in approxi-mately 15,000 gardens nationwide. For moreinformation, see www.bto.org/gbw/index.htm

ResultsCoverageTable 1 summarises the staggering number offorms received, routes visited, flocks recordedand birds counted in each of the three wintersof the survey. In total, Casual Records andWinter Walks supplied 69,000 records of 4.3million birds. Across the three winters, a total of651 Winter Walks routes were visited, whichinvolved volunteers walking in excess of 22,000km!

The distribution of Winter Walks routes andCasual Records (figs. 1b and 1c) approximatelymatched that of the BTO membership (fig. 1a),except that the areas of highest membershipdensity (large urbanised areas) had few routes,presumably owing to a lack of nearby farmland.Coverage also included most of the geographic

range of farmland (fig. 1d), although there werestriking gaps in Winter Walks coverage infenland and the West Midlands, while thedensity of routes was poor in Scotland.

Observer effort in the Winter Walks surveycould vary in two ways: first in the length of theroute and second in the number of visits madeper winter. Mean route length was 3.7 km. Mostroutes (60%) were 1-3 km in length and only15% exceeded 5 km in length. In all threewinters, 75-77% of routes were visited up to 10times between November and February and 6-7% of routes were visited more than 20 times.There was no significant difference in thenumber of visits between winters (square roottransformed counts, ANOVA, F2,1019 = -0.55,P=0.58) and so data were combined acrosswinters.

Species prevalence and abundanceThe most widespread species on farmland wereCommon Chaffinch Fringilla coelebs, Fieldfareand Common Starling Sturnus vulgaris, allbeing reported from over 75% of Winter Walksroutes (table 2). Of the declining farmland birdspecies, Sky Lark, Song Thrush T. philomelosand Yellowhammer E. citrinella were allreported from over 50% of sites but TreeSparrow and Corn Bunting were reported fromonly 14% and 8% of routes respectively (table2). The majority of species showed no cleartrends in reporting through the winter. Some,however, showed consistent trends across thethree winters and fig. 2 shows examples of thisin three common small passerines of farmland.The Sky Lark reporting rate decreased throughNovember and December but then, in the NewYear, began to increase, probably because mildweather in late winter enticed some birds tobegin taking up territories, making them moreapparent to the casual observer. In marked con-trast, both Meadow Pipit Anthus pratensis andPied Wagtail Motacilla alba showed consistentdeclines in reporting rate from November toFebruary (fig. 2). Why this should be so is notentirely clear. Perhaps flocks are easy to find inearly winter when they feed on recently tilledfields but become progressively harder to see ascrops grow taller. Other explanations mayinclude a switch to a different habitat, not well-covered by these surveys, or simply that adecline in reporting rate reflects winter mor-tality. In other species, the trends indicated dif-fering abundance from one year to the next. In



two winters, Bramblings Fringilla montifringillawere present on approximately 5% of routesevery week, but in winter 2000/01 they were vir-tually absent, a pattern mirrored in gardens(Garden BirdWatch). This was probably becauseautumn 2000 had one of the best beechmastcrops for decades and so these attractive finchesremained in woodlands and did not need toventure into gardens and farmland.

The total number of each species reported isalso given in table 2. While there is undoubtedlysome duplication, it shows some interestingpatterns. Common Starling, Lapwing, EuropeanGolden Plover Pluvialis apricaria and Fieldfarewere amongst the most reported and mostabundant species. Far fewer Tree Sparrows andCorn Buntings were reported on Winter Walksthan their close relatives. Striking differences arealso apparent in the reporting of some speciesbetween the two surveys. Bullfinches Pyrrhula

pyrrhula, for example, were frequently encoun-tered on Winter Walks but rarely recorded onCasual Records forms, probably because theyseldom formed large flocks or joined otherspecies, and hence failed to exceed the 20-indi-vidual threshold required to be reported viaCasual Records.

Selected species accountsFor each of the five key species we include amap showing all records from the two surveys.For each in turn we then consider abundance,seasonal trends in reporting and measures ofhabitat association. It should be reiterated thatthese habitat associations indicate only whichhabitats were used and not which were pre-ferred, since the surveys did not measurehabitat availability. So, for example, regionaldifferences in habitat use may merely reflectregional differences in which habitats are avail-



Table 2. Target species of the Winter Walks and Casual Records surveys. %R is the percentage of Winter Walksroutes (n = 651, totalled across three winters) on which each species was reported.

WW and CR are the total number of individuals of each species reported by the two surveys.

%R WW CR

Grey Partridge Perdix perdix 23% 4,606 1,856European Golden Plover Pluvialis apricaria 19% 164,772 671,573Northern Lapwing Vanellus vanellus 57% 233,118 864,648Common Snipe Gallinago gallinago 20% 1,905 45,524Eurasian Curlew Numenius arquata 12% 14,593 2,594Stock Dove Columba oenas 33% 12,596 9,669Wood Lark Lullula arborea 1% 51 138Sky Lark Alauda arvensis 60% 38,308 39,055Meadow Pipit Anthus pratensis 53% 18,171 12,534Pied Wagtail Motacilla alba 63% 11,793 8,460Common Stonechat Saxicola torquata 16% 844 1,161Fieldfare Turdus pilaris 79% 169,035 248,572Song Thrush T. philomelos 67% 5,432 2,057Redwing T. iliacus 71% 68,723 57,162Mistle Thrush T. viscivorus 64% 5,936 269Common Starling Sturnus vulgaris 78% 308,018 744,120House Sparrow Passer domesticus 54% 19,419 4,615Tree Sparrow P. montanus 14% 3,431 5,377Common Chaffinch Fringilla coelebs 84% 86,818 71,106Brambling F. montifringilla 8% 1,007 9,553Greenfinch Carduelis chloris 67% 18,526 21,988Goldfinch C. carduelis 59% 15,365 22,886Linnet C. cannabina 35% 29,704 50,341Twite C. flavirostris 3% 909 12,648Lesser/Common Redpoll C. cabaret/flammea 9% 941 1,341Bullfinch Pyrrhula pyrrhula 40% 2,354 122Snow Bunting Plectrophenax nivalis 1% 542 4,667Yellowhammer Emberiza citrinella 58% 27,229 19,775Reed Bunting E. schoeniclus 29% 5,091 4,538Corn Bunting E. calandra 8% 3,186 7,415

able. Full results for all 30 species can be foundonline via www.bto.org/surveys/special/wfbs/introduction.htm



Grey PartridgeGrey Partridges werereported from scatteredlocalities throughoutcentral and easternEngland, with very fewin Wales and Scotland(fig. 3a). Over 600 sight-ings were reported viaWinter Walks comparedwith only 86 fromCasual Records. WinterWalks ‘flocks’ ranged insize from 1 to 57, with75% numbering 10 indi-viduals or fewer, andonly 6% numbering 20or more. Twenty birdswas the minimumthreshold for reportingflocks to Casual Recordsand this explains why sofew were reported viathat survey.

There was no sea-sonal trend in the per-centage of Winter Walksroutes that reportedGrey Partridges, butthere was a shallowdecline in the averagenumber per sightingfrom November to Feb-ruary. This was mirroredin Casual Records witharound 30-35% of allbirds being reported inNovember, dropping toonly 15% in February.Perhaps birds wereincreasingly missed ascrops grew taller; alter-natively they maybecome harder to seewhen supplementaryfeeding is withdrawn atthe end of the shootingseason.

On Winter Walks,14% of birds were asso-ciated with pastures and

a further 25% with crops (of which 84% werecereal, 7% were oilseed rape), 23% with stub-bles (83% cereal), and 11% with bare till, while

Fig. 2. Weekly reporting rates of (a) Sky Lark Alauda arvensis, (b) Meadow PipitAnthus pratensis, and (c) Pied Wagtail Motacilla alba on Winter Walks routes.

Different symbols indicate different winters: squares = 1999/00, triangles = 2000/01and circles = 2001/02.Week 1 is 1st-7th November.

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8% were associated with boundary habitatssuch as the hedge bottoms and rough vegeta-tion around the edges of fields.

Northern LapwingLapwings were reported from all areas,although in Wales small numbers were found incoastal districts only and in Scotland most birdswere in the southern lowlands (fig. 3b). Lap-wings were most abundant in eastern England,whereas central and western areas had morepatchy occupancy. Some regional bias isexpected since most records were likely to have

come from areas with most people (fig. 1a), i.e.the south and east. Nonetheless, many WinterWalks routes in the west were visited withoutplovers being found, suggesting that their distri-bution is genuinely skewed towards easternareas. There was little evidence of seasonal shiftsin distribution nor of seasonal trends inreporting rate and abundance betweenNovember and February.

Maximum flock sizes were 7,000 fromCasual Records and 5,650 from Winter Walks.Large flocks were not the norm, however, andonly 25% of flocks exceeded 120 birds. Nation-

124


British Birds 97 • March 2004 • 118-129

Fig. 3. Maps showing the distribution within Britain of five farmland bird species, based on records from bothCasual Records and Winter Walks: (a) Grey Partridge Perdix perdix; (b) Northern Lapwing Vanellus vanellus;

(c) Sky Lark Alauda arvensis; (d) Fieldfare Turdus pilaris; and (e) Tree Sparrow Passer montanus.Those 10-km squares receiving at least some coverage from one or other survey are shown in grey.

(a) (b) (c)

(e)(d)

ally, approximately 25% of Lapwings werereported from cereal crops, 25% from grass, and15% from plough and harrow. Less than 10% ofbirds were associated with stubbles, mostlycereal (56-80%), maize (0-27%) and sugar beetstubbles (7-8%). There were marked regionaldifferences in habitat use, with proportionatelymore birds on crops and bare till in east andwest England, and greater use of pasture else-where. In Wales, 25% were on bare till. Use ofstubbles was rare except in eastern England.

Sky LarkThe distribution of Sky Larks was similar tothat of Lapwings, with birds being widespreadin England, but present in Wales and the south-west only near the coast. Flocks peaked at 500-700 birds but at least half the reported WinterWalks flocks numbered four or fewer. Largerflocks were reported from Casual Records, partlyowing to the cutoff at 20 individuals, but prob-ably also owing to the difficulty of recordingthis skulking species when walking a set route.Reporting rates increased in late winter, asshown earlier (fig. 2a). Approximately half of allSky Larks were associated with stubble fields:70-80% of these were on cereal stubbles (thecommonest stubble type) with fewer on stub-bles of bean, linseed, oilseed rape, maize, sugarbeet or turnips. Crops accounted for up to 18%

of records, of which about 75% were on cerealcrops and 10-15% on oilseed rape crops. Onlyabout 10% of birds were on grass fields. Minorregional differences were evident: the propor-tion of birds on stubbles varied from 32% inEast England to 73% in Scotland, while the useof grass peaked in Scotland and that of bare tillpeaked in Wales.

FieldfareFieldfares were widespread, with perhaps morerecords in central and western England than inthe east (fig. 3d). Although some large flocks ofFieldfares were reported, with maxima being1,950 from Casual Records and 5,000 fromWinter Walks, 50% of flocks numbered fewerthan 15 individuals. Reporting rates indicated adecline in reporting through the winter. IfFieldfares were moving out of farmland, theymight have been moving into gardens insteadand thus boosting numbers there, yet trends ingardens matched those on farmland, evenacross winters: in 2000/01 Fieldfares were scarceboth on Winter Walks routes and in gardens upuntil midwinter before they increased.

Nationally, boundary habitats, mostlyhedgerows and trees, were most important,accounting for 34% of birds. Grass accountedfor 13-26% of birds, crops 15-25% and stubbles7%. Of those on crops, 80-96% were on cereals



65. During the Winter Walks/Casual Records surveys, Northern Lapwings Vanellus vanellus were most frequentlyencountered in eastern England (see fig. 3), and comparison of these results with data from the Winter Atlas (Lack1986) suggests that proportionally more Lapwings are wintering in the east than was the case in the early 1980s.

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(the remainder being oilseed rape and beancrops), while cereals, maize and sugar beet werethe most frequently used stubbles. Interestingly,the percentage of Fieldfares on boundary habi-tats during Winter Walks declined from 37% inNovember, through 27% in December to 16%in January before increasing slightly to 21% inFebruary. Was this indicative of birds depletingthe hedgerows of berries, or a more profitablehabitat becoming available elsewhere?

Tree SparrowTree Sparrows were patchily distributed, absentfrom much of Scotland and Wales (althoughthere were few observers here), but also rarelyencountered in East Anglia, southern coastalcounties or the southwest (fig. 3e). Flocks num-bered up to 100-200 birds but 75% of flocksnumbered ten individuals or fewer and therewere no significant seasonal trends in eitherreporting rate or abundance. True to theirname, 25-50% of Tree Sparrows were associatedwith hedges and trees. Only 4-7% were associ-ated with crops, and the type of crop differedbetween the two surveys: Casual Records found43% of crop associations to be with linseedcrops (which is particularly noteworthy giventhat linseed is not a common crop) and 22%with cereals, while Winter Walks found 58%with cereals and 24% with maize. Overall, 17%of Tree Sparrows were associated with stubbles,mostly cereal (86% from Casual Records) andsugar beet stubbles (54% from Winter Walks).

Compared with House Sparrows P. domesticus,far fewer Tree Sparrows were associated withfarmyards (25% and 3-5% respectively).

DiscussionIn their own right, Winter Walks and CasualRecords have given interesting insights into theecology of farmland birds in winter. They showthat, despite agricultural changes, Britain’sfarmland is still used by significant numbers ofbirds in winter, but that there are causes forconcern. Some of our granivorous species arebecoming extremely scarce in winter and thismirrors the trends apparent during thebreeding season. Species such as Tree Sparrow,Corn Bunting and even House Sparrow werereported from far fewer Winter Walks routesthan one might have expected two decadesearlier. Some species are becoming so scarcethat understanding their ecology from rigor-ously controlled surveys is difficult because sofew are likely to be found in randomisedsquares. For such species, broad participationsurveys such as Casual Records and WinterWalks may be the only way of amassing infor-mation on a large scale.

Despite the limitations of coverage achievedby Winter Walks, it is still possible to comparethe distribution maps presented here with thosefrom the Winter Atlas (Lack 1986). For GreyPartridge, Sky Lark, Fieldfare and Tree Sparrowthe extent of the distributions derived fromWinter Walks and Casual Records were broadly



66. Survey results showed that about half of all Sky Larks Alauda arvensis recorded were associated with stubble fields, and, of these, most (up to 80%) were on cereal stubbles.

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similar to those in the Winter Atlas. Yet therewere perhaps more gaps in the Grey Partridgeand Tree Sparrow distributions. These ‘gaps’ inrange could be due to incomplete coverage ofthese areas compared with the more thoroughfieldwork of the Winter Atlas, but such lossesare also reported by county bird reports and,furthermore, match well-documented losses inthe breeding season (Gibbons et al. 1993).These surveys also suggest that proportionallymore Lapwings and Fieldfares winter in the eastthan was the case in the early 1980s. This isperhaps because recent winters have tended tobe mild and lacked prolonged periods withfrozen ground which might normally forcethese species to seek refuge and milder condi-tions farther south and west.

One drawback of simple surveys such asWinter Walks and Casual Records is that it is dif-ficult to collect detailed information about thehabitats used in relation to their availability. Inaddition, differences in detectability, bothbetween species and between habitats, confuseactual patterns of habitat use. Nonetheless,some comparisons can be made. For instance,though 14% of Sky Larks were associated withcereal crops, cereal crops account for 24% of

farmland in winter (Gillings & Fuller 2001).Moreover, over 50% of Sky Larks were associ-ated with stubbles, despite stubbles accountingfor less than 6% of farmland (Gillings & Fuller2001). These patterns are in agreement withother extensive (Gillings & Fuller 2001) andintensive studies (Wilson et al. 1996; Buck-ingham et al. 1999; Donald & Vickery 2001).

Our results suggest that Grey Partridgesmade wide use of crops, stubbles and grass,though Wilson et al. (1996) and Buckingham etal. (1999) both demonstrated a preference forstubbles and set-aside over pasture, and theavoidance of arable crops and bare tillage. Potts(1986) described the diet of Grey Partridges inwinter as consisting of weed seeds and spiltgrain but also observed that they would switchto grazing pasture if seeds were lacking, whichexplains their catholic choices.

Lapwings showed equal use of crops andgrass rather than being concentrated in grass asmight be expected (Lister 1964). This is perhapsan indirect consequence of their easterly distri-bution. Regional specialisation of agriculturehas meant that less pasture exists now in easternBritain and then usually as short-rotationimproved grass, which has low earthworm



67. Fieldfare Turdus pilaris, East Sussex, February 1991. Survey results suggested that these northern thrushes wereencountered less frequently in late winter than earlier in the season. Boundary habitats, in particular hedgerows,

were found to be important and, perhaps as reserves of berries were depleted, the birds moved on, to newhabitats or areas.

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abundance (Edwards & Bohlen 1996; Vickery etal. 2001) and probably presents poor feedingopportunities. Many birds were associated withstanding water on agricultural fields and this isprobably because field flooding can produce atemporary resource of drowned earthworms.

Not surprisingly, most Fieldfares recordedwere associated with hedges. Within fields,more were associated with grass than withcrops, reflecting the species’ distributional biastowards pastoral and mixed farming landscapes(fig. 3d). Wilson et al. (1996) and Perkins et al.(2000) showed that Fieldfares were more likelyto occur on grazed than ungrazed pastures. Thismight be because sheep produce a tightlycropped sward which may in turn facilitatedetection of earthworm and tipulid prey.Detailed questions such as these, relatinghabitat use to both availability and habitatmanagement, will be addressed by the randomsquare survey and other BTO studies.

For some species (e.g. Sky Lark), the resultsof Casual Records and Winter Walks supportedresults from local and intensive studies of abun-dance and habitat use, and suggested that theymay reflect more general patterns. For somespecies, regional results differed from those ofprevious studies (e.g. Lapwing). These surveys

have also provided new information on distrib-ution and abundance which, alongside therandom square survey, should enable us to con-sider shifts in range and local losses of farmlandbird populations in relation to agricultural landmanagement. BB subscribers and BTOmembers have further shown how amateurbirdwatchers can provide an invaluable resourcewith which we can investigate the ecology offarmland birds and use the results to informconservationists and decision-makers.

Acknowledgments

Primarily we must thank the hundreds of birdwatchers whowalked all those kilometres and counted all those birds toprovide the information on which this paper is based.Thanks go to Andy Wilson for organisational support, andJuliet Vickery and Phil Atkinson for useful comments. Thiswork was funded under a partnership of the BTO and theJoint Nature Conservation Committee (on behalf ofEnglish Nature, Scottish Natural Heritage and theCountryside Council for Wales, and also on behalf of theEnvironment and Heritage Service in Northern Ireland).

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Chamberlain, D. E., Fuller, R. J., Bunce, J. C., Duckworth,J. C., & Shrubb, M. 2000. Changes in the abundance offarmland birds in relation to the timing of agricultural



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69. Results showed that the distribution of Tree Sparrows Passer montanus was patchy, this species being largely absent from the southwest, counties along the south coast and much of East Anglia,

despite relatively good survey coverage.

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Simon Gillings and Peter Beaven, BTO, The Nunnery, Thetford, Norfolk IP24 2PU

wintering farmland birds · 1999) may have altered the range and abun-dance of farmland birds in...

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