Numbers and distribution of Northern Lapwings Vanellus vanellus breeding in England and Wales in 1998

This paper presents the results of the BTO/RSPB survey of breeding Northern Lapwings Vanellus vanellus in England and Wales carried out in 1998. Numbers of breeding Lapwings and land-use types were recorded by volunteers in 1312 randomly selected tetrads using identical methods to those adopted in a previous survey in 1987. The results suggest a population of 62 923 breeding pairs (95% confidence intervals 55 268 to 74 499), representing a 49% decline in 11 years. The declines were greatest in southwest England and Wales, resulting in a marked contraction in range. Both arable and pastoral farmland was found to be important for Lapwings, highlighting their vulnerability to changes in a range of agricultural systems. Recent major changes in land management practices, including the switch from spring to autumn sowing and the conversion of rough to intensively managed, improved grassland is likely to have reduced both the area and the suitability of these habitats for Lapwings. Grassland within arable areas is known to provide important chick rearing habitat, and spring tillage with adjacent grassland was significantly more likely to hold Lapwings than spring tillage that did not abut grass fields. The prevalence of grass and spring tillage fields in close proximity has declined in recent years with the loss of traditional mixed farming and the polarization of pastoral systems in the west of Britain and arable in the east. The implications of these results for the conservation of Lapwings are discussed and it is recommended that, in the light of the scale of the decline recorded, Lapwings should be afforded much higher conservation priority in Britain than they are at present. The range contraction has resulted in high numbers being concentrated on reserves, highlighting the importance of sensitive management of these areas for this species. However, wider countryside measures should also be considered, such as specific options within agri-environment schemes, designed to enhance farmland habitats for Lapwings.     

Population dynamics and reproduction of Northern Lapwings Vanellus vanellus in a meadow restoration area in central Sweden

To investigate the effectiveness of a meadow restoration programme, we studied the relationships between population changes and environmental changes, return rates and hatching success in a population of Northern Lapwings Vanellus vanellus. The study was performed on mixed farmland (59 km²) in central Sweden, an area that underwent extensive meadow restoration between 1985 and 1994. The study included more than 2600 nests, supplemented with observations of 127 individually colour-ringed Northern Lapwings. The breeding population varied (2.7–5.3 pairs/km²), but showed no significant trend with time. The population increased in years with high spring flooding levels. Population size was unrelated to demographic factors (e.g. hatching success the previous year (14–50%), and return rate). Lapwings moved considerably between years and their nest site fidelity was unrelated to previous hatching success or other factors, suggesting that changes in habitat quality and migration between populations were important in regulating population size. Recent extensive meadow restoration did not seem to aid the Northern Lapwing population; birds continued nesting on tillage even though most nests were destroyed by farming activities. A relatively high relaying frequency improved hatching success, which was still lowest in the most preferred habitats (spring sown crops, total hatching success c. 30%). The few Northern Lapwings breeding in the least preferred habitats (meadows and cultivated grassland) had a better hatching success (> 70% total hatching success), suggesting that habitat selection was not determined by hatching success. From these results, recommendations are made for the management of Northern Lapwing (and associated species) populations on farmland.     

Age at first breeding, philopatry and breeding site-fidelity in the Lapwing Vanellus vanellus

Breeding Lapwings Vanellus vanellus were studied in the Eden Valley (Cumbria) and in Teesdale (County Durham) between 1990 and 1992. A total of 300 adult Lapwings and 801 near-fledged young were uniquely colour-ringed. Breeding adults were highly site-faithful, almost always nesting in the same or an adjacent field in successive years. Second-year birds were less site-faithful, with more birds nesting in adjacent and other fields and fewer in the same field in successive years. In Teesdale, 74% of colour-ringed young Lapwings returned in their first or second year of life to within 5 km from where they hatched. In contrast, in the Eden Valley only 37% of young birds in their first or second year of life returned to within 5 km from where they hatched. From an analysis of British ringing recoveries in April and May, 61% of Lapwings were recovered within 10 km from where they were ringed as chicks. A further 11% were recovered more than 100 km from where they were ringed. Young Lapwings were highly philopatric, with 45% of males and 52% of females breeding in the same field or a field adjacent to where they hatched. The majority of Lapwings (67%) began breeding at 1 year old. Of the remaining birds, 27% bred for the first time when 2 years old and 6% for the first time in their third year of life. There was no difference between the sexes. Chicks hatching and subsequently fledging late in the season returned less frequently to the study areas in subsequent years than did chicks hatching earlier in the season.     

Predation of Lapwing Vanellus vanellus nests on lowland wet grassland in England and Wales: effects of nest density, habitat and predator abundance

There is concern that predation of Lapwing Vanellus vanellus nests may create additional pressure on declining populations of this species in Europe. At seven sites in England and Wales, daily nest predation rates on 1,390 nests were related to variables using Generalised Linear Mixed Models. The strongest predictor was Lapwing nest density (number of nests within 100 m): predation rates declined as nest density increased. Since nocturnal species, probably mammals, have been identified as the major predators of Lapwing nests at these sites, these results suggest that Lapwings are able to deter mammalian predators or may settle to nest at high densities in areas with low predation pressure. At the site level, there was no relationship between Lapwing nesting density and fox density, and a positive relationship with Carrion Crow Corvus corone nesting density. There was a weaker effect of distance to field boundary: nests closer to boundaries were more likely to be predated. Weak interactive effects between crow density and both nest visibility and distance to vantage point were identified in models using a reduced subset of nests. These were counter-intuitive, did not persist in the larger data set, and do not have obvious explanations. If Lapwings nesting at high density are able to deter predators, there are implications for land management. Smaller areas could be managed within potential breeding habitat to encourage Lapwings to nest in dense colonies. Selection of larger fields for such management, where nests could be located far from the field boundary should improve the value of such measures.     

Quantifying the effects of habitat structure on prey detectability and accessibility to farmland birds

For species that rely on visual cues to detect prey items, increasing the structural complexity of a patch can greatly influence forager behaviour through consequent reductions in prey detectability and accessibility. These effects are likely to manifest themselves in terms of foraging site selection and there is plentiful evidence for preferential site selection for a suite of taxa. However, the underlying effects of habitat structure on foraging behaviour, which are likely to drive these observed site selections, are much less well understood. We present the results of two studies designed to quantify the effects of vegetation structure on prey detectability and accessibility to avian invertebrate feeders and granivores on farmland. There was a significant negative relationship between potential prey detectability and both distance and vegetation height in cereal crops and stubbles for Northern Lapwings Vanellus vanellus . The interscan distance travelled by Lapwings differed significantly between habitats, with longer distances travelled in cereal crops and harrowed compared with ploughed soil and grasses. The peck rate, head-up rate and mean search period of foraging Chaffinches Fringilla coelebs were not affected by increasing vegetation structure but forager mobility was significantly reduced. We hope that by quantifying the effects of vegetation structure on prey detectability and accessibility we can highlight the importance of considering these factors, as well as prey abundance, when developing management strategies for farmland birds.     

Soil pH and organic matter content add explanatory power to Northern Lapwing Vanellus vanellus distribution models and suggest soil amendment as a conservation measure on upland farmland

Habitat associations of farmland birds are well studied, yet few have considered relationships between species distribution and soil properties. Charadriiform waders (shorebirds) depend upon penetrable soils, rich in invertebrate prey. Many species, such as the Northern Lapwing Vanellus vanellus, have undergone severe declines across Europe, despite being targeted by agri‐environment measures. This study assessed whether there were additive effects of soil variables (depth, pH and organic matter content) in explaining Lapwing distribution, after controlling for known habitat relationships, at 89 farmland sites across Scotland. The addition of these soil variables and their association with elevation improved model fit by 55%, in comparison with models containing only previously established habitat relationships. Lapwing density was greatest at sites at higher elevation, but only those with less peaty and less acidic soil. Lapwing distribution is being constrained between intensively managed lowland farmland with favourable soil conditions and upland sites where lower management intensity favours Lapwings but edaphic conditions limit their distribution. Trials of soil amendments such as liming are needed on higher elevation grassland sites to test whether they could contribute to conservation management for breeding Lapwings and other species of conservation concern that depend upon soil‐dwelling invertebrates in grassland soils, such as Eurasian Curlew Numenius arquata, Common Starling Sturnus vulgaris and Ring Ouzel Turdus torquatus. Results from such trials could support improvement and targeting of agri‐environment schemes and other conservation measures in upland grassland systems.     

Arrival and habitat use by Lapwings Vanellus vanellus in the early breeding season

The arrival on the breeding grounds and habitat use in relation to agricultural land use by Lapwings Vanellus vanellus was compared in rough grazing and arable study areas in the Midland Valley of Scotland. First arrivals took place in early February. Males preceded females and territory occupation by the males began soon after first arrival. During the pre-breeding period birds remained in flocks and day time habitat use and activity was strongly influenced by the lunar cycle. Birds fed mainly in those habitats in which prey (leatherjackets and earthworms) were most plentiful, and in which their feeding success was high. The choice of nesting habitat was not influenced by food availability in the immediate vicinity of the nest site but by the crypticity of the clutch and incubating adults. On rough grazing birds preferred unimproved land while on arable land spring cereal was the preferred habitat. The choice of actual nesting field on the arable land was influenced by the risk of predation and the proximity of suitable feeding fields for the adults and chicks.     

Diurnal Variability In The Detection Of Dunlin Calidris alpina

The paper describes aspects of the feeding ecology and behaviour of Lapwings and Golden Plovers in an area southeast of York during the winter of 1984–85. Both species chose winter cereal (autumn-sown winter wheat and barley) in preference to other field types, including grassland. A comparison of winter cereals with Ings (permanent, unimproved alluvial meadows, traditionally farmed and subject to winter flooding) revealed no significant differences in the daily behaviour patterns, feeding rates (pecks per minute) or capture rates of large prey items by Lapwings. Lapwings reached highest numbers in winter cereals 8–¸10 cm high.     

Influence of environmental factors on the numbers and activity of wintering Lapwings and Golden Plovers

Variations in the numbers and activity of Lapwings Vanellus vanellus and Golden Plovers Pluvialis apricaria using 322 ha of lowland farmland were examined in relation to temperature, rainfall, wind speed and moonphase. The study was undertaken over two winters (1987/88 and 1988/89), with maximum counts of 4000 Lapwings and 820 Golden Plovers. Patterns of occupancy of the study area and seasonal occurrence are described. Temperature and the phase of the lunar cycle seemed to be particularly important in affecting the distribution and activity of the birds. More Lapwings occurred in the study area on the colder and on the wetter days in several months, and also around the full moon period when feeding activity was particularly prevalent. A higher proportion of Lapwings tended to feed on colder days and around the new moon period, while daytime loafing increased around the full moon period. These results support the ideas that birds need to feed more in cold conditions, when energy demands are high, and that night feeding frequently occurs during the full moon period, although the reasons for this remain unclear.     

Effects of age, cohort and individual on breeding performance in the Lapwing Vanellus vanellus

The breeding performance of individually colour-ringed Lapwings Vanellus vanellus was studied on marginal grassland in Upper Teesdale, County Durham (UK), from 1992 to 1995. Contrary to many studies of birds, female age had only a minor effect on breeding performance: yearling females produced eggs on average 5% smaller than those of adults. In contrast, the average productivity of male Lapwings was estimated to increase by around 40% between one and two years of age, and by a further 10% between two and three years of age. This was because of a 40% increase in the proportion of males that bred between one and two years of age, and of an increase in mating success with age coupled with a higher breeding success for polygynous males. The likelihood of breeding for male Lapwings was affected by year of hatching. More than half of those males that hatched in 1990, and which were present in both 1993 and 1994, did not breed. It was suggested that this was due to environmental effects experienced by these males as chicks, resulting in reduced success in securing a breeding territory later in life. Individual female Lapwings showed a high degree of consistency between years in both laying date and egg size, and those that raised up to two young in 1993 raised approximately the same number in 1994. However, females producing more than two young in 1993 raised significantly fewer in 1994, perhaps suggesting a cost of reproduction.     

The influence of landscape features on nest predation rates of grassland‐breeding waders

In Europe, lowland wet grasslands have become increasingly fragmented, and populations of waders in these fragments are subject to unsustainably high levels of nest predation. Patches of taller vegetation in these landscapes can support small mammals, which are the main source of prey for many predators. Providing such patches of habitat could potentially reduce levels of nest predation if predators preferentially target small mammals. However, predator attraction to patches of taller vegetation for foraging, shelter, perching and/or nesting could also result in local increases in predation rates, as a consequence of increased predator densities or spill‐over foraging into the surrounding area. Here we assess the influence of taller vegetation on wader nest predation rates, and the feasibility of managing vegetation structure to alter predator impacts. Between 2005 and 2011, the nest distribution and hatching success of Northern Lapwings Vanellus vanellus, which nest in the open, and Common Redshanks Tringa totanus, which conceal their nests in vegetation, were measured on a 487‐ha area of wet grassland in eastern England that is primarily managed for breeding waders. Predation rates of Lapwing nests increased significantly with distance from patches of taller vegetation, and decreased with increasing area of taller vegetation within 1 km of the nest, whereas neither variable influenced Redshank nest predation probability. These findings suggest that the distribution and activity of nest predators in lowland wet grassland landscapes may be influenced by the presence and distribution of areas of taller vegetation. For Lapwings at least, there may therefore be scope for landscape‐scale management of vegetation structure to influence levels of predation in these habitats.     

Mating systems in the Lapwing Vanellus vanellus

The Lapwing Vanellus vanellus has traditionally been regarded as a monogamous, single brooded species, defending a single territory. Recent studies involving individually recognizable Lapwings have begun to challenge the ubiquity of these statements, with high frequencies of polygyny and the production of second broods being reported. Breeding Lapwings were studied in Upper Teesdale, County Durham, U.K., between 1993 and 1995, where both adults and chicks had been individually colour-ringed since 1990. A total of 90 territorial males and 64 females were intensively studied during the 3 years. Overall, 30% of territorial males had more than one mate in any year, with 19% more adult males than yearling males mating polygynously. On two occasions, polygynous males simultaneously defended two territories. Five females attempted to produce second broods, and one was polyandrous.     

Nesting success in Redshank Tringa totanus breeding on coastal meadows and the importance of habitat features used as perches by avian predators

Capsule Nest survival rates could not be explained by distance to habitat edges or other features used by predators.

Aims To investigate if predation on Redshank nests was affected by habitat characteristics at a local scale.

Methods We examined survival rates of Redshank nests on coastal meadows on the Baltic island of Gotland, Sweden, over two breeding seasons. We analysed nest survival rates in relation to several habitat characteristics that may benefit predators searching for nests. We examined existing studies concerning predation rates on wader nests in relation to edges and habitat features potentially used by avian predators.

Results We found no significant effects of distance to habitat edge or to nearest potential lookout for avian predators or to shoreline. Abundance of Lapwings Vanellus vanellus, an aggressive species with active nest-defence, did not have any significant effect on nest survival rate, nor did vegetation concealment of nests. Nest survival rates were significantly different between years and lower later in the season.

Conclusions There is only weak support for general effects on wader nest predation rates of proximity to edges and features used by avian predators. Simple mechanical management actions such as removal of trees and bushes on coastal meadows may not directly, and by itself, result in higher reproductive success of waders. Further understanding is needed of the behaviour of predators and the composition of the predator community in different landscapes in order to increase the efficiency of management actions to remove threats to vulnerable species on coastal meadows.     

Resident female Northern Lapwings Vanellus vanellus fight to exclude settlement by secondary females

In systems with bi‐parental care, sexual conflict theory states that a transition from monogamy to polygyny should increase fitness prospects for males and reduce fitness prospects of resident females. Behavioural observations of Northern Lapwings Vanellus vanellus suggested that resident females try to monopolize their breeding resources by attacking females prospecting for secondary status, and males commonly respond by intervening on behalf of the prospecting females. In four territories the resident females successfully defended their monogamous status, in nine territories the resident females made at least one successful eviction before being forced to accept polygyny and in nine territories observed eviction attempts were unsuccessful. These observations indicate that mating status in Northern Lapwings is partly determined by the competitive ability of resident females.     

The energetic implications of precocial development for three shorebird species breeding in a warm environment

We investigated the effect of body size, parental behaviour and timing of breeding on the chick growth and energetics of three precocial shorebird (Charadrii) species in a warm sub-tropical environment: the Kittlitz's Plover Charadrius pecuarius , Blacksmith Lapwing Vanellus armatus , and Crowned Lapwing V. coronatus . The three species exhibited slower growth, longer pre-fledging periods and lower energy expenditure during the pre-fledging period than Arctic and temperate zone relatives of similar size. It was found that relative growth rates of charadriid and scolopacid species increased by 1.77% per degree latitude. Blacksmith and Crowned Lapwings are of similar size (i.e. about 160 g), about four times the mass of Kittlitz's Plovers. Taking body mass into account, the resting metabolic rate and daily energy expenditure of the three study species were similar. The relative amounts of energy needed for chicks to grow from a hatchling to a fledgling were low for the three species studied. The relative amount of energy needed to complete growth in charadriid and scolopacid species increased by 2.54% per degree latitude. Because Crowned Lapwings exhibited faster growth than Blacksmith Lapwings but similar daily energy expenditure we suggest that Blacksmith Lapwings compensate for greater energy expenditure in colder weather by growing more slowly. We suggest that small growth rate coefficient, low resting metabolic rate and low daily energy expenditure are adaptations to lower food availability and milder ambient temperatures in sub-tropical breeding habitats compared to temperate or Arctic regions.     

Movements of wintering Dunlin Calidris alpina and changing habitat availability in an agricultural wetland landscape

Few studies have assessed how the dynamics of wetland bird movements relate to changing resource availability, particularly at more than one spatial scale. Within western Oregon's Williamette Valley, we examined winter resident Dunlin Calidris alpina movements in relation to a decrease in availability of preferred shorebird foraging habitat from early to late winter of 1999–2000. By tracking movements of 15 (early winter) and 12 (late winter) radiomarked individuals, we calculated home ranges and characterized presence/absence of a preference for shorebird foraging habitat during each winter period. Between periods, we compared: (1) percentage of shorebird habitat in home ranges to its availability in the landscape (regional preference), (2) percentage of radio locations in shorebird habitat to its availability within home ranges (local preference) and (3) relative use of roost sites. Concurrent with a 75% decrease in available shorebird habitat from early to late winter, average home range sizes increased by a factor of 3.8. At a regional scale, home ranges in early winter included a significantly greater percentage of shorebird foraging habitat than was available in the wider landscape. However, by late winter, the percent of shorebird habitat in home ranges did not match availability in the landscape. At the local scale, for both winter periods Dunlin were located in shorebird foraging habitat more often than expected given availability of habitat within home ranges [Correction added after online pub-lication 23 May 2008: sentence amended]. An increase in the number of roosts used from early to late winter implies possible reliance on additional sites in late winter for foraging opportunities. Results suggest that wet, unvegetated habitat is sought by Dunlin throughout winter, but individuals could not select home ranges in late winter that fully compensated for seasonal loss of habitat.     

Trade-offs in nest site selection in coastal populations of Lapwings Vanellus vanellus

In coastal populations of Lapwings Vanellus vanellus in southwestern Sweden, arable fields predominated as foraging habitat before laying. Females caught more large prey items on arable fields and shores than on pastures. Close to egg laying, females foraged mainly near their future nest sites. Arable land and pastures were used to a similar extent for nesting. We found no difference in nest predation between habitats. Egg volume varied among females and was correlated with wing-length, body mass and condition. Mean egg volume also was positively correlated with feeding time on arable land before laying. Pairs nesting on arable fields therefore generally produced larger eggs than those on pastures. The distances between nests and chick foraging areas, however, were significantly longer for birds nesting on arable land than for those on pastures. Moreover, in 2 of 3 years, the proportion of hatched chicks that survived until fledging was negatively correlated with this distance. There was no difference in chick survival between broods hatched on arable fields and pastures. We suggest that nest site selection and offspring production involve a trade-off between the benefits of nesting close to rich feeding grounds for adults and the costs of moving long distances between nest sites and chick-rearing areas.     

The impact of livestock on Lapwing Vanellus vanellus breeding densities and performance on coastal grazing marsh

Capsule Even at very low stocking densities, livestock reduce breeding densities of adult Lapwings and increase the risk of nest loss due to predation.

Aims To assess the effects of livestock on Lapwings breeding on coastal grazing marshes.

Methods Densities of breeding adults, clutch sizes, laying dates, incubation schedules, clutch and chick survival were compared between marshes grazed at low stocking densities (0.2–0.51 livestock units/ha) and marshes where livestock had been excluded. Repeated measurements of sward heights were also made.

Results. Breeding densities in 1995 and 1997, but not 1996, were negatively correlated with the presence of livestock. Though few nests were trampled, livestock disrupted incubation schedules and increased the risk of nest predation. Clutches were smaller on grazed marshes than on ungrazed marshes, while more clutches were also laid later on grazed marshes. Grazed swards remained shorter, and more suitable for nesting, longer than ungrazed swards but clutches laid later in the season were more likely to be predated.

Conclusion The exclusion of livestock from selected areas to increase the nesting success of lapwings is a desirable option on coastal grazing marshes where the rate of grass growth is slow in spring. Grazing regimes are suggested that would maintain relatively short swards, provide refuge to Lapwings from livestock during the peak nesting period, and allow grazers to exploit all of their marshes.