Meadow Pipit Anthus Pratensis Research Articles

Variation in reproductive success in a fragmented Meadow Pipit population: a role for vegetation succession?

Most farmland birds experience strong declines across Europe. These declines are typically associated with agricultural intensification but research on alternative local causes remains scarce. We investigated variation in reproductive success as a potential driver for the observed population declines in a fragmented population of the Meadow Pipit Anthus pratensis, a representative inhabitant of extensively managed mountain grasslands across Europe. Intense nest surveys in the entire Meadow Pipit metapopulation of the Northern Black Forest (SW Germany) between 2020 and 2022 provided information on reproductive success for 53 females distributed across nine habitat patches along an 18 km ridge of the Northern Black Forest. Hatching dates delayed by approx. 5.0 days per 100 m altitude and were almost 10 days later in a year with cold and rainy spring weather. Mean reproductive success per female and year (3.45 fledglings) was low compared to literature values (approx. 4.5) and may thus drive ongoing population declines. Mayfield nest survival estimates (approx. 51% across the nesting period) were comparably high, with most nest failures linked with predation or adverse weather. Low reproductive success further associated with comparably small clutch sizes and low fractions of second broods in habitat patches characterized by homogeneously dense swards. We suggest that restoration through extensive permanent cattle grazing coupled with succession control may be a key factor to increase population productivity.

Food Provisioning and Body Mass of Nestling Meadow Pipits and Cuckoos

Common Cuckoos Cuculus canorus are obligate brood parasites, laying eggs in nests of other species. Cuckoo nestlings are often thought to be insatiable, compared to host broods. However, in Reed Warblers Acrocephalus scirpaceus and a few other species, cuckoo nestlings are fed at most only as frequently as a host brood. To add to the small body of knowledge on feeding frequencies and body mass development of Cuckoo nestlings, I studied Cuckoos using another host, the Meadow Pipit Anthus pratensis, in the Dutch dunes (2019–2021). By filming feeding parents (hosts) I determined the provisioning frequency for broods of Pipits and for nestling Cuckoos. I found that nestling Cuckoos receive on average fewer feeds per hour than broods of Meadow Pipits. Furthermore, overall Cuckoos received as many feeds during their 22-day nestling period as a brood of Pipits during their 13 days in the nest. At 13 days of age (day 1 is the day of hatching), the single Cuckoo was as heavy as a brood of four Meadow Pipits. At 22 days, the maximum weights of the nestling Cuckoos were greater than the Meadow Pipit broods and varied between 91 and 105 g. Thus, although Cuckoos are being fed less frequently, young Cuckoos are heavier at fledging than a whole brood of Pipits. This could be because Cuckoos are fed larger prey. Alternatively, Cuckoos may require less food because their thermoregulatory costs could be smaller: they have almost black skin which absorbs solar radiation efficiently, do not have to compete with siblings in the nest and, once older and feathered, have a smaller surface-to-volume ratio than a Pipit brood of four nestlings.

Effects of overhead power‐lines on the density of ground‐nesting birds in open sub‐arctic habitats

Yearly electricity production has increased steadily worlwide in recent decades and the associated overhead power lines are widespread and occur across urban and natural habitats, and often in remote areas where there is little other anthropogenic influence. Here we assessed the effects of overhead power lines on the density of ground‐nesting birds in the Icelandic lowlands, which host several populations of international importance. The combined breeding density of the eight study species increased significantly from ~ 112 birds/km2 close (< 50 m) to the power lines to ~ 177 birds/km2 away (450–500 m) from the power lines, with two of these species (Eurasian Whimbrel Numenius phaeopus and Common Redshank Tringa totanus) increasing significantly with distance from power lines and six species (European Golden Plover Pluvialis apricaria, Common Snipe Gallinago gallinago, Meadow Pipit Anthus pratensis, Black‐tailed Godwit Limosa limosa, Dunlin Calidris alpina and Redwing Turdus iliacus) showing no changes. These findings suggest that power lines can influence the breeding density of ground‐nesting bird species in their vicinity and that accounting for such effects when planning future infrastructure will be imperative.

The Shetland Bird Survey: population trends for widespread breeding birds 2002–2019

ABSTRACT Capsule Population trends are estimated for the first time for 12 species based on Shetland Breeding Bird Survey data collected between 2002 and 2019. Aim To provide population trends for a selection of commoner breeding waders and passerines on the Shetland Isles, the most northerly region of the UK, which has historically been under-represented in national bird monitoring schemes. Methods One hundred and forty-five self-selected 1-km2 squares were surveyed between 2002 and 2019 using similar methods to the BTO/JNCC/RSPB Breeding Bird Survey (BBS), the main breeding bird monitoring scheme in the UK. Results Over 17 years, Eurasian Oystercatcher Haematopus ostralegus, Northern Lapwing Vanellus vanellus, and Common Redshank Tringa totanus populations declined whilst Eurasian Curlew Numenius arquata and Common Snipe Gallinago gallinago showed no significant changes in their population trends. For passerines, Common Skylark Alauda arvensis and Northern Wheatear Oenanthe oenanthe populations declined, whilst Common Starling Sturnus vulgaris, Common Blackbird Turdus merula, and House Sparrow Passer domesticus increased. Winter Wren Troglodytes troglodytes and Meadow Pipit Anthus pratensis showed no significant population changes. Comparisons with BBS trends for the UK and for Scotland are provided. For Eurasian Curlew, Common Starling, and House Sparrow, trends were more favourable in Shetland than elsewhere in UK. Conclusion The Shetland Breeding Bird Survey provides useful trends for several bird species, which include important breeding numbers of Winter Wren and Common Starling (both endemic subspecies), as well as nationally important wader populations. We recommend increasing the number of survey squares sampled each year, which would increase the precision of population estimates. The inclusion of a random or stratified element to square selection would help to ensure that these trends are representative of the wider region.

Can microclimate offer refuge to an upland bird species under climate change?

Climate change is a severe threat to biodiversity. Areas with a high variety of microclimates may provide opportunities for species to persist in a changing climate. Test the extent to which microclimate is an important determinant of the distribution of a widespread upland passerine, the meadow pipit Anthus pratensis, and whether microclimate becomes an increasingly important determinant of distribution towards the warm edge of the species’ range. We used models of the occurrence of meadow pipits based on data from an extensive survey to identify macroclimate and topographic associations, the latter as proxies of microclimate. We assessed magnitude and direction of the effects of microclimate and whether the magnitude of microclimate effects increases as macroclimate suitability declines. The probability of meadow pipit occurrence is significantly correlated with macroclimate and microclimate. Microclimate accounts for about a third of the variation in occupancy probability and has a stronger effect than macroclimate at all three spatial scales considered. Elevation and topographical wetness index are positively correlated with meadow pipit occurrence, while insolation is negatively correlated. Elevation and macroclimate suitability show a positive interaction, while insolation and macroclimate suitability show a negative interaction. Microclimate substantially influences the distribution of the meadow pipit. For high latitude and upland species such as this, suitable areas on cool slopes could form the focus for conservation protection, as these areas are likely to become increasingly utilised and may remain the only locations occupied in otherwise unsuitable climate.

Declining peatland bird numbers are not consistent with the increasing Common Crane population

The Common Crane (Grus grus) population has experienced an unprecedented increase across Europe during the last decades. Although cranes feed mostly on invertebrates, amphibians and berries during the breeding season, they can also eat eggs and young of other birds. Therefore, conservationists have raised concerns about the potential predatory effect of cranes on wetland avifauna, but the effects of crane predation on bird numbers have so far not been investigated. We here test the relationship between the crane and peatland bird population’ abundances in Finland for five common wader and passerine species, and a set of seven less common waders, using line-transect data spanning from 1987 to 2014. We found that the population densities of two small passerines (Meadow Pipit Anthus pratensis and Western Yellow Wagtail Motacilla flava) and one wader species (Wood Sandpiper Tringa glareola) were positively associated with crane numbers, probably related to a protective effect against nest predators. For the two other common species and the set of less common waders, we did not find any significant relationships with crane abundance. None of the species was influenced by the (lagged) effect of crane presence (i.e. years since crane was first observed). Peatland drainage was responsible for most species’ negative densities, indicating the need to protect and restore peatlands to mitigate the loss of peatland bird diversity in Finland. In addition, openness, wetness and area size were important peatland characteristics positively influencing most of the studied bird populations. The development in crane and other mire bird numbers in Europe should be monitored regularly to reveal any possible future predatory effects contributing to the shaping of the peatland bird community.

Benefits and costs of native reforestation for breeding songbirds in temperate uplands

Global tree planting initiatives may benefit biodiversity depending on woodland type, but ecological effects must be understood when woodland replaces open habitats supporting characteristic wildlife. In the UK's temperate uplands, large-scale reforestation is replacing long-established open ‘moorland’ (heath, bog and grassland) supporting breeding bird communities of conservation importance. We quantified breeding bird species richness and abundance in 8–24 year-old native woodland plantations in Scotland and adjacent moorland and used bird densities to predict potential future abundance changes in woodland and moorland avian indicator species from recent national-level woodland creation policies. Bird species richness at point counts increased with increasing woodland cover, height and age and declined with increasing elevation. Differing abundances of bird species of conservation concern between woodland and moorland were related to their associations with vegetation measures, especially woodland cover and tree species composition. The creation of 54.9 km2 of native woodland in Scotland across 2017 and 2018 predicts reduced Meadow Pipit Anthus pratensis (moorland indicator) abundance of 6214 individuals or 0.13% of current UK population, and increased Willow Warbler Phylloscopus trochilus (indicator of young woodland) abundance of 6040 individuals or 0.13% of current UK population. Native woodland plantations comprised c34% of new woodland creation and the projections should be extended to other woodland types in particular non-native commercial conifer forestry. Native reforestation of open ground offers net gains in bird species richness but could disbenefit open-ground birds including those of conservation concern. Where retention of open-ground species is desired, landscape-scale reforestation should consider both woodland and open-ground wildlife.

Brood parasitism on Meadow Pipits Anthus pratensis by Common Cuckoos Cuculus canorus in two mountain areas in Norway

In the period 2001–2014 we studied Common Cuckoo Cuculus canorus brood parasitism on Meadow Pipits Anthus pratensis in two mountain areas; one located in the eastern and one in the western part of southern Norway. In the total material of 211 Meadow Pipit nests, 14 (6.6%) were parasitized by the cuckoo. The parasitism rate showed considerable variation both in time and space, with highest rate in one of the areas in 2005 (35.3%). Cuckoo eggs were quite similar in appearance to host eggs. In spite of this, 30% of the cuckoo eggs were rejected by desertion. No host ejection of parasite eggs was observed. Nest predation rates were rather low. Due to climate change, it has been hypothesized that the cuckoo, a long-distance migrant, may arrive too late to successfully utilize the Meadow Pipit because the latter is better able to advance the breeding season due to a shorter migration distance. Our data lend support to the mismatch hypothesis, but the low sample size regarding cases of parasitism does not allow us to make any firm conclusions. Long-term monitoring of host-parasite interactions in specific populations is important to further disclose the mechanisms responsible for the decline in the Norwegian cuckoo population.

Simulated Rainfall Reduces the Insulative Properties of Bird Nests

Bird nests are variable in design but all are constructed for the purpose of incubation. The potentially onerous energetic costs of incubation have meant that previous studies have focussed on thermal insulation but nests are often exposed to a variety of environmental factors, including rainfall. Those few studies that have investigated the effects of water on nests have saturated the walls by soaking but this may not reflect what a nest would typically encounter in situ during rainfall. Here, nests of four species of songbird (Common Chaffinch Fringilla coelebs, Common Linnets Linaria cannabina, Meadow Pipits Anthus pratensis, and Whinchats Saxicola rubetra) were investigated using temperature loggers to determine the effect of simulated rainfall on nest wall insulation. Simulated rainfall, produced by water dripping through a coffee percolator, significantly reduced the insulatory values of nests, and significantly increased the rate of cooling of temperature loggers inside the nest cup. No significant effect of species, or nest mass, was observed. Even when wet nest walls provided some insulation but whether this is attributable to the nest materials chosen by each species was not clear. The nest site chosen by the birds may also offer considerable protection from the weather. Further research is needed to better understand how rainfall affects the insulative properties of nests in situ.

Breeding ground correlates of the distribution and decline of the Common Cuckoo Cuculus canorus at two spatial scales

Many migratory bird species are undergoing population declines as a result of potentially multiple, interacting mechanisms. Understanding the environmental associations of spatial variation in population change can help tease out the likely mechanisms involved. Common Cuckoo Cuculus canorus populations have declined by 69% in England but increased by 33% in Scotland. The declines have mainly occurred in lowland agricultural landscapes, but their mechanisms are unknown. At both the local scale within the county of Devon (SE England) and at the national (UK) scale, we analysed the breeding season distribution of Cuckoos in relation to habitat variation, the abundance of host species and the abundance of moth species whose caterpillars are a key food of adult Cuckoos. At the local scale, we found that Cuckoos were more likely to be detected in areas with more semi‐natural habitat, more Meadow Pipits Anthus pratensis (but fewer Dunnocks Prunella modularis) and where, later in the summer, higher numbers of moths were captured whose larvae are Cuckoo prey. Nationally, Cuckoos have become more associated with upland heath characterized by the presence of Meadow Pipit hosts, and with wetland habitats occupied by Eurasian Reed Warbler Acrocephalus scirpaceus hosts. The core distribution of Cuckoos has shifted from south to north within the UK. By the end of 2009, the abundance of macro‐moth species identified as prey had also declined four times faster than that of species not known to be taken by Cuckoos. The abundance of these moths has shown the sharpest declines in grassland, arable and woodland habitats and has increased in semi‐natural habitats (heaths and rough grassland). Our study suggests that Cuckoos are likely to remain a very scarce bird in lowland agricultural landscapes without large‐scale changes in agricultural practices.

Comparative Breeding Biology of Three Insectivorous Songbirds in Dutch Dune Grasslands

Scholars agree that changes in vegetation have been influencing population sizes of ground-foraging songbirds in Dutch dune grasslands. Due to a lack of knowledge concerning the breeding biology of these species, the mechanisms linking vegetation change and population development remain unclear. Here, I describe the breeding biology of three co-occurring insectivores in Dutch dune grasslands: Meadow Pipit Anthus pratensis, European Stonechat Saxicola torquatus and Northern Wheatear Oenanthe oenanthe. The nestling diet of Meadow Pipits contained many dipterans, such as crane flies (Tipulidae), but almost no beetles and relatively few noctuid caterpillars, whereas beetles and noctuid larvae were important in the diets of both European Stonechat and Northern Wheatear nestlings. Mean brood size was smallest in Meadow Pipit and equal in European Stonechat and Northern Wheatear. Nest depredation was similarly high in the open-nesting Meadow Pipit and European Stonechat, resulting in lower nest success compared ...

Changes in the breeding bird communities on mires and in surrounding forests in southeastern Norway during a 40-year period (1976–2015)

The breeding bird communities of 18 mires and surrounding forests in southeastern Norway were censused in 1976–77 and in 2015. We found that 53% of the mire species with sufficient data for analyses showed significant changes. Red-throated Diver Gavia stellata, Common Crane Grus grus, Wood Sandpiper Tringa glareola and Tree Pipit Anthus trivialis increased, whereas Northern Lapwing Vanellus vanellus, Black-headed Gull Chroicocephalus ridibundus, Meadow Pipit Anthus pratensis and Yellow Wagtail Motacilla flava decreased. There were also near significant decreases of Eurasian Curlew Numenius arquata and Eurasian Skylark Alauda arvensis. Population changes did not differ between short- and long-distance migrants. Species with marginal populations on mires declined more than mire specialist species, suggesting an indirect negative influence of problems in other habitats. Overall, there was a significant 19% decline in number of mire species, but a non-significant 7% increase in number of individuals. The bird community in the forests surrounding the mires showed significant population changes for 42% of the species with sufficient data for analyses, with increases in many resident forest species, but less so for migrants. Overall, there was a near significant 12% increase in number of forest species, and a significant 28% increase in number of individuals. Mire- and forest-associated species did not differ in population trends. Among short-distance migrants (mire and forest species combined), species wintering in agricultural habitats had more negative population changes than species wintering in other habitats. Thus, the breeding bird community on and around mires in this part of Norway has undergone large changes during the last 40 years. We discuss our results in relation to general trends of bird communities in northern Europe.

Effect of Climate Change on Mediterranean Winter Ranges of Two Migratory Passerines.

We studied the effect of climate change on the distribution of two insectivorous passerines (the meadow pipit Anthus pratensis and the chiffchaff Phylloscopus collybita) in wintering grounds of the Western Mediterranean basin. In this region, precipitation and temperature can affect the distribution of these birds through direct (thermoregulation costs) or indirect effects (primary productivity). Thus, it can be postulated that projected climate changes in the region will affect the extent and suitability of their wintering grounds. We studied pipit and chiffchaff abundance in several hundred localities along a belt crossing Spain and Morocco and assessed the effects of climate and other geographical and habitat predictors on bird distribution. Multivariate analyses reported a positive effect of temperature on the present distribution of the two species, with an additional effect of precipitation on the meadow pipit. These climate variables were used with Maxent to model the occurrence probabilities of species using ring recoveries as presence data. Abundance and occupancy of the two species in the study localities adjusted to the distribution models, with more birds in sectors of high climate suitability. After validation, these models were used to forecast the distribution of climate suitability according to climate projections for 2050–2070 (temperature increase and precipitation reduction). Results show an expansion of climatically suitable sectors into the highlands by the effect of warming on the two species, and a retreat of the meadow pipit from southern sectors related to rain reduction. The predicted patterns show a mean increase in climate suitability for the two species due to the warming of the large highland expanses typical of the western Mediterranean.

Экология лугового конька Anthus pratensis (Linnaeus, 1758) на северо-восточном пределе гнездового ареала

Экология лугового конька Anthus pratensis (Linnaeus, 1758) на северо-восточном пределе гнездового ареала

The ecology of the meadow pipit Anthus pratensis (Linnaeus, 1758) at the northeastern limit of the breeding area

The ecology of the meadow pipit was studied for many years in nature in the Lower Ob region and on the Yamal Peninsula. Experimental studies were carried out in laboratory conditions at natural and alternative day durations. The factors affecting the distribution of the species at the northeastern limit of its area were analyzed. The meadow pipit is widespread in the taiga zone; it does not need special adaptations for its existence in forest tundra and southern taiga. However, the species has no adaptations that would permit it to exist in northern tundra. Current climate changes define the northern border of the area. The species has no obvious obstacles for spreading to the east.

Bird communities at two marshes in Øvre Forra, today and 40 years ago

In the protected area Ovre Forra in Central Norway, birds were surveyed at two marshes in two succeeding years at the beginning of the 1970s. By following the same survey procedure 40 years later in these unchanged marsh habitats, I sought changes in the breeding bird community. While the total number of waders seems to have been quite stable, the abundance of some of the involved species might have changed during this period of time. Due to low numbers, and annual variations, the implications for some of the involved species have to be taken cautiously. The most abundant species in Ovre Forra is now the Common Redshank Tringa totanus . This species has outnumbered the earlier most abundant species in this bird community, the Meadow Pipit Anthus pratensis . The numbers of the Meadow Pipit, Northern Lapwing Vanellus vanellus , European Golden Plover Pluvialis apricaria and Common Sandpiper Actitis hypoleucos all tend to be lower than for 40 years ago. The Common Gull Larus canus and two Tringa species, the Common Redshank T. totanus and Common Greenshank T. nebularia , seem to have increased in numbers, while the situation for the Common Snipe Gallinago gallinago and the Whimbrel Numenius phaeopus appears to be stable. The Ruff Calidris pugnax used to be a characteristic species on the Ovre Forra’s bogs in the 1970s, but has since vanished. Altogether, the study shows an apparently quite stable avifauna over the time span of 40 years in this environmentally stable reserve.

Influence of Landscape and Field-Level Agricultural Management on a Mediterranean Farmland Winter Bird Community

We studied the response to agricultural management factors of birds wintering in an unirrigated cereal farmland area of central Spain, examining the influence on species richness, abundance and community composition of different field-level and landscape-level agricultural management variables related to intensification. Our initial hypothesis was that landscape-level management factors exert a stronger effect on wintering bird species richness, total abundance and community composition than field-level ones. The particular responses of the most frequent species (skylark Alauda arvensis, corn bunting Emberiza calandra and meadow pipit Anthus pratensis) were also examined. Richer assemblages were found in more substrate-diverse plots with natural vegetation patches or in plots with higher yield crops, while the more abundant ones, dominated by the skylark, occupied more homogeneous areas dominated by cereals and arable land. As expected, landscape-level management factors explained a much greater proportion of variance in community composition compared to field-level factors (71% vs 29%, respectively). Species richness per se was favoured by substratediverse plots containing patches of natural vegetation, but also by plots where cereal crops were more productive in the previous harvest, declining in more homogeneous plots dominated by cereal crops and arable land in general. Conversely, skylark abundance and total abundance increased as landscapes became more homogeneous and dominated by cereals and arable land, although the relationship for total abundance only approached significance. Results suggest that the current landscape structure and levels of agricultural production of cereal farmland in central Spain can host relatively abundant winter populations of seed-eating and open landscape specialists like the skylark, although certain levels of habitat diversity need to be guaranteed to ensure the maintenance of rich wintering bird communities.

Using ring records and field surveys to predict the winter distribution of a migratory passerine

Capsule Ring records can be used to predict spatial changes in habitat suitability in wintering grounds of migratory birds as shown by a case study with the Meadow Pipit (Anthus pratensis).Aims To forecast the winter distribution of the Meadow Pipit in the Iberian Peninsula and the Maghreb (1 700 000 km2) by combining ring records and fields surveys.Methods We processed winter ring records with Maxent, a popular machine-learning technique used to predict the occurrence probability of species. We then tested whether the occurrence probabilities predicted by the model were significantly positively related to the actual abundance of the Pipit in Spain and Morocco.Results Occurrence probabilities provided by Maxent explained 6% of Pipit abundance distribution in partial least squares regression analyses. There was, in addition, a weak effect of geographical location (1.5%) and a strong effect of local vegetation (17.6%) on Pipit distribution. The occurrence probabilities were used to classify the winter range of the Meadow Pipit in sectors of high, medium and low suitability. The most suitable sector occupied 9% of the region (153 000 km2) and was restricted to warm and moist lowlands where Pipits gather in grasslands.Conclusion These results support the potential usefulness of cartographic models derived from ring records to describe the wintering range of migratory birds.

Foraging site choice and diet selection of Meadow Pipits Anthus pratensis breeding on grazed salt marshes

Capsule Breeding Meadow Pipits foraged for caterpillars and large spiders in vegetation that was less heterogeneous than vegetation at random locations.Aims To gain a better understanding of the foraging ecology of breeding Meadow Pipits on grazed coastal salt marshes, we tested three hypotheses: (1) there is a positive relation between vegetation height and prey abundance, (2) adult birds preferentially forage at locations with great heterogeneity in vegetation height, thereby maximizing both food abundance and accessibility, and (3) adult birds forage selectively for specific prey items.Methods We measured food availability in relation to vegetation structure, habitat use and nestling diet for six individual nests. Nestling diet was determined by microscopic analysis of faeces while food availability over different vegetation heights was estimated by suction sampling. Information on habitat use was gathered by direct observation. Foraging locations were compared to random locations at the same distance from the nest.Results Nestling diet mainly consisted of larger spiders (> 5 mm) (38% of prey individuals), caterpillars (c. 2 cm) (38%), other insect larvae (12%) and flies and wasps (7%). There was a positive relationship between vegetation height and prey availability. Contrary to predictions, vegetation at Pipit foraging locations was less heterogeneous than at random locations, yet we found no evidence for a preference for short or tall vegetation. We found strong evidence for selective foraging for larger prey, since the relative abundance of especially large spiders and caterpillars was much higher in the faecal samples than in the field. This diet differed considerably from Meadow Pipit diet reported from other habitats.Conclusion These findings suggest that the creation of heterogeneity in vegetation height by grazing or otherwise may not be invariably beneficial to breeding Meadow Pipits.

Hur påverkas fågelfaunan av upphörd betesdrift – data från en 26 år lång inventeringsstudie

The breeding bird fauna of a 1.6 km2 large grassland area in southwestern Sweden was monitored in 1987–2012, using the point count method. The area was grazed by approximately 500 cattle until 2006, and the grass height was then at most 10–15 cm except for higher tussocks. From 2007 onwards, when the grazing had ceased, the grass increased in height to 20–30 cm and became much thicker. The average number of bird species per year was 44.7 over the 26 year survey period. Numbers of some farmland birds such as Lapwing Vanellus vanellus, Skylark Alauda arvensis, Starling Sturnus vulgaris, and Linnet Carduelis cannabina decreased in the study area, following the general pattern in the whole of Sweden. Meadow Pipit Anthus pratensis, Corn Crake Crex crex, Whinchat Saxicola rubetra and Grasshopper Warbler Locustella naevia increased in the area, but decreased in Sweden in general over the same period. The local changes in bird numbers in the study area seem mainly to be caused by an increased grass height and thickness as a consequence of ceased cattle grazing.