Carrion Crows Corvus Corone Research Articles

Effect of implementation of irrigation on raptor and corvid populations in a Mediterranean agrosystem

We analyzed changes in the composition of the community of birds of prey and corvids in a rainfed agrosystem after the transformation of 37.2 % of the sampled area into irrigated land between 2005 and 2020. We sampled 57 transects (372 km per year) and fitted generalized linear mixed models (GLMM) to study changes in species occurrence. Our results showed that specific richness and the Shannon index did not vary significantly between rainfed and irrigated transects, but there was a certain positive trend when comparing the years 2005 and 2020. Regarding the differences detected for each species, the occurrence of Montagu’s harrier Circus pygargus, hen harrier Circus cyaneus, Eurasian short-toed eagle Circaetus gallicus, griffon vulture Gyps fulvus and carrion crow Corvus corone was significantly lower in irrigated land than in rainfed land, while magpie Pica pica, Western marsh harrier Circus aeruginosus, common kestrel Falco tinnunculus and black kite Milvus migrans showed a significantly higher occurrence in the irrigated transects. In addition, our findings confirm a significant decrease in occurrence between 2005 and 2020 both in rainfed and irrigated areas for Montagu’s harrier, hen harrier and magpie, while Western marsh harrier, golden eagle Aquila chrysaetos, common buzzard Buteo buteo, red kite Milvus milvus, griffon vulture Gyps fulvus, red-billed chough Pyrrhocorax pyrrhocorax and Western jackdaw Coloeus monedula were detected significantly more frequently in 2020 than in 2005. These results suggest that assessment of the impact of a new irrigation system should focus on the most characteristic species of rainfed agrosystems because the apparently positive effect on other species, equally protected but more generalist, may mask the real effect on conservation.

Effects of meteorological conditions on brood care in cooperatively breeding carrion crow and consequences on reproductive success

Meteorological stressors (e.g., temperature and rain shortage) constrain brood provisioning in some bird species, but the consequences on reproductive success have been rarely quantified. Here we show, in a cooperatively breeding population of carrion crow Corvus corone in Spain, that individual feeding rates decreased significantly with rising air temperatures both in breeders and helpers, while lack of rain was associated with a significant reduction in the effort of the male helpers as compared to the other social categories. Group coordination, measured as the degree of alternation of nest visits by carers, was also negatively affected by rising temperature. Furthermore, we found that the body condition of the nestlings worsened when temperatures were high during the rearing period. Interestingly, the analysis of a long-term data set on crow reproduction showed that nestling body condition steadily deteriorated over the last 26-years. Although many factors may concur in causing population changes, our data suggest a possible causal link between global warming, brood caring behaviour and the decline of carrion crow population in the Mediterranean climatic region of Spain.

Varying response of breeding waders to experimental manipulation of their habitat and predators

Many ground-nesting bird species including waders are of conservation concern across Europe. Population declines of Eurasian Curlew Numenius arquata (hereafter Curlew), a globally Near-threatened wader, exemplify this and are driven by low breeding success due to predation, and loss and degradation of breeding habitat. We tested whether the combined delivery of vegetation management and lethal control of Red Foxes Vulpes vulpes and Carrion Crows Corvus corone and Hooded Crows C. cornix improved Curlew nesting success and breeding abundance across UK study sites over five years. On trial sites, vegetation management improved habitat condition and Curlew distributions shifted towards managed areas. However, changes in predator abundances, Curlew nesting success and Curlew breeding abundance did not differ between trial and reference sites. Northern Lapwing Vanellus vanellus numbers increased on trial sites and decreased on reference sites, whilst Common Snipe Gallinago gallinago numbers showed no treatment response. Some of these outcomes were associated with additional environmental variables added to Treatment:Year terms in three-way interactions (changes in fox abundance associated with abundance of non-native gamebirds; changes in Crow abundance associated with gamebirds and woodland area; changes in Curlew nesting success associated with crow abundance), highlighting that outcomes depend on site-specific contexts, and consistent responses to interventions cannot be assumed. The difficulty in increasing Curlew nesting success likely relates to underlying mesopredator densities in the UK, which are known to be high in a European context. Our results suggest that a model of delivery like this study, including management of predators using lethal control, at comparable intensities, is highly unlikely to be effective for Curlew or Snipe within agri-environment schemes, but could be for Northern Lapwing. To make progress on wader recovery it is imperative to understand the underlying drivers of high mesopredator densities and address these through landscape-scale intervention and policy changes.

Fauna and seasonal dynamics of birds number at the solid waste landfill and their possible impact on the activities of Kyzyl airport

In 20192020, as a part of the ecological and ornithological survey in Kyzyl airport and the aerodrome area, the birds of the municipal solid waste landfill located near the runway were studied in order to assess the impact of the landfill on the safety of aircraft flights. The observations carried out during the year revealed the species composition of the avifauna of the polygon, the background species of the polygon, and the annual population dynamics of each species. The black kite Milvus migrans Bodd., the mongolian gull Larus vegae mongolicus Sushk., the oriental carrion crow Corvus corone Eversm., and the common raven Corvus corax L. were classified as the most numerous aircraft-hazardous species of the landfill. daurian partridge Perdix dauurica Pall., Eurasian tree sparrow Passer montanus L. and house sparrow P. domesticus L., common starling Sturnus vulgaris L. and some other species of Passeriformes were also included in the background. Two periods of the maximum total number of birds at the landfill were identified: winter (January, February) and late summer (August). According to the conducted records of the number and characteristics of behavior the black kite is the greatest danger to flights; the most dangerous period is the end of August, when this species forms pre-flight clusters on the landfill. Such clusters can be up to 1500 birds in size. In the cold season, the most dangerous species are the common raven and the oriental carrion crow.

Sexing first-calendar-year Carrion Crows Corvus corone from biometrics reveals variation between years in post-fledging sex ratio

ABSTRACT Sex is an important parameter to consider when studying population dynamics and movement ecology, for example, though sex determination is often difficult in young birds of sexually monomorphic species, with large biometric overlap between sexes. We aimed at determining the sex of first-calendar-year (1cy) Carrion Crows, in order to study temporal trends in sex ratio. We performed molecular sexing of a sample of 48 females and 45 males, creating a statistical framework to confidently discriminate sexes using four morphometric variables. Although biometrics overlapped between sexes, we developed a discriminant function which separated the sexes with high accuracy (88%). Then we applied this discriminant function to biometrics obtained from all 1cy individuals captured, to determine their sex. We found a female-biased overall sex ratio of the captures: female Carrion Crows might therefore be more numerous than males, or more prone to enter traps. There were significant variations in sex ratio between years, but not between months.

Cheating Cheaters: Social Monogamy but Genetic Polygamy in a Brood Parasite

Understanding the variability of mating systems is central in the study of animal behaviour. The advent of genetic techniques allowed combining social and genetic data, providing a more comprehensive view of reproductive strategies. In obligate avian brood parasites, the lack of constraints derived from offspring care allows for great plasticity of the mating system in response to changes in socio-ecological conditions. This potential for intraspecific variation makes brood parasites ideal model species to investigate the evolution of reproductive behaviour. We simultaneously studied for the first time social and genetic patterns of reproduction of the Great Spotted Cuckoo Clamator glandarius, combining radio-tracking and behavioural observations in the field with genetic parentage analyses. Our results reveal that loose pair bonds can be maintained in this species despite high levels of genetic polygamy and lack of territoriality, possibly because of the need of intra-pair cooperation for finding and parasitising the nests of its large hosts: the Carrion Crow Corvus corone and the Eurasian Magpie Pica pica. We also found that cuckoos mostly ranged around suitable foraging grounds, but females moved larger distances to find host nests to parasitise. Comparison of our results with previous reports on different populations also suggests a plasticity of Great Spotted Cuckoo territorial behaviour that may depend on population density, host choice and distribution of host nests.—Bolopo, D., Roncalli, G., Canestrari, D. & Baglione, V. (2020). Cheating cheaters: social monogamy but genetic polygamy in a brood parasite. Ardeola, 67: 39-56.

Flock-fishing deep-diving piscivores (Great Crested Grebe Podiceps cristatus, Great Cormorant Phalacrocorax carbo, Common Merganser Mergus merganser) at Lake Vombsjön, southern Sweden, and those that exploit them

Lake Vombsjön in southern Sweden is visited by large numbers of Great Crested Grebes Podiceps cristatus (>2000), Great Cormorants Phalacrocorax carbo (sometimes >1000) and Common Mergansers Mergus merganser (up to 2000) in late autumn and early winter. Different species exploit them. Great Crested Grebes are used especially by commensal Common Gulls Larus canus; the gulls take advantage of fish that flee towards the surface. Common Gulls also use cormorants and mergansers in the same way but also try to kleptoparasitize them. Both Herring Gulls Larus argentatus and Great Black-backed Gulls Larus marinus kleptoparasitize these two species, while Red Kites Milvus milvus, Grey Herons Ardea cinerea and Carrion Crows Corvus corone use them commensally. White-tailed Eagles Haliaeetus albicilla seem to use both methods to obtain fish. On 50% of one hundred visits during November to March, eagles were seen flying low over the fishing flocks. They would fly a metre or so above the flocks and then accelerate and attack a bird holding a fish. The bird would then either try to escape by a rush or by diving, dropping the fish which the eagle seized. Interestingly, the flock-fishing birds showed no fear reactions towards the eagles but appeared to regard them similarly to large gulls.

Ecological role of vertebrate scavengers in urban ecosystems in the UK.

Recent research has demonstrated how scavenging, the act of consuming dead animals, plays a key role in ecosystem structure, functioning, and stability. A growing number of studies suggest that vertebrate scavengers also provide key ecosystem services, the benefits humans gain from the natural world, particularly in the removal of carcasses from the environment. An increasing proportion of the human population is now residing in cities and towns, many of which, despite being highly altered environments, contain significant wildlife populations, and so animal carcasses. Indeed, non‐predation fatalities may be higher within urban than natural environments. Despite this, the fate of carcasses in urban environments and the role vertebrate scavengers play in their removal have not been determined. In this study, we quantify the role of vertebrate scavengers in urban environments in three towns in the UK. Using experimentally deployed rat carcasses and rapid fire motion‐triggered cameras, we determined which species were scavenging and how removal of carcass biomass was partitioned between them. Of the 63 experimental carcasses deployed, vertebrate scavenger activity was detected at 67%. There was a significantly greater depletion in carcass biomass in the presence (mean loss of 194 g) than absence (mean loss of 14 g) of scavengers. Scavenger activity was restricted to three species, Carrion crows Corvus corone, Eurasian magpies Pica pica, and European red foxes Vulpes vulpes. From behavioral analysis, we estimated that a maximum of 73% of the carcass biomass was removed by vertebrate scavengers. Despite having low species richness, the urban scavenger community in our urban study system removed a similar proportion of carcasses to those reported in more pristine environments. Vertebrate scavengers are providing a key urban ecosystem service in terms of carcass removal. This service is, however, often overlooked, and the species that provide it are among some of the most disliked and persecuted.

Increased mammalian predators and climate ch1ange predict declines in breeding success and density of Capercaillie tetrao urogallus, an old stand specialist, in fragmented Scottish forests

Low breeding success has been associated with declines in population and range of the re-introduced Capercaillie Tetrao urogallus in Scotland. Annual breeding success from 26 Scottish forests surveyed between 1991 and 2009 averaged only 0.6 chicks per female, the lowest rate recorded in 16 previous studies. Reduced breeding success was due to proportionally fewer females rearing chicks rather than a reduction in brood size. Birds bred less well in Perthshire at the southern edge of the range, where declines in indices of female and male density were highest. Only at the core of the range (Strathspey), where birds bred better, were female densities stable. Two weather variables, April temperature in the pre-breeding period (APRTEMP), and temperature at chick hatch in June (HATCHTEMP), increased over the study period. Indices of Pine Marten Martes martes increased 3.9-fold since 1995, and those of Red Fox Vulpes vulpes by 2.2-fold, whereas those of Carrion Crow Corvus corone, raptors and forest floor vegetation showed no change. Neither forest type nor forest ground vegetation appeared to influence breeding success. Instead, females reared more chicks in years when hatch time in June was drier, and in forests with lower marten and crow indices. In addition, more females reared broods in years when Aprils were cooler. Brood size was unaffected by any of the measured variables. Densities of adult birds were lower in forests with higher fox indices. Increased predation of clutches and chicks by martens and crows within these small, fragmented forests, as well as changes in climate, may explain reductions in breeding success and hence contribute to continued declines. Successful conservation of Capercaillie in remaining Strathspey strongholds may require better predator management, including a licensed removal of martens to test the hypotheses that martens contribute to reduced breeding success. This short-medium term approach will inform longer-term predator management policies and complement aspirations to increase the area and connectivity of forest habitat to benefit Capercaillie in-part through mitigating against any impact of increasing forest-edge predators.

Coastal saltpans are a good alternative breeding habitat for Kentish plover Charadrius alexandrinus when umbrella species are present

The loss and degradation of natural habitats in coastal areas worldwide has adversely affected many waterbird species, changing their breeding distribution and reducing their productivity. Anthropogenic habitats such as saltpans can provide alternative or complementary habitats for waterbirds and mitigate the increasing human impact on natural coastal habitats. Unvegetated linear paths between salt ponds are used by ground‐nesting waterbird species to breed but their linear structure may facilitate the detection of nests by predators. This negative effect may, however, be counterbalanced by the advantages of breeding in mixed colonies. To evaluate the importance and the risks of breeding in saltpans we used the Kentish plover Charadrius alexandrinus breeding in coastal saltpans of southern Portugal as a model species. Specifically, we assessed the role of nest‐site characteristics, predation and nesting proximity to species with aggressive antipredator behaviour (black‐winged stilt Himantopus himantopus) on their breeding success. Kentish plovers selected nest‐sites on the edges of paths, with about 20% of water around the nest, and a mean visibility of more than 72%; however nest‐site characteristics were not correlated with nesting success. Predation was the main cause of nest loss in saltpans (42%); carrion crows Corvus corone were responsible for most daylight nest predation (58%) and red fox (Vulpes vulpes; 73%) for night predation. An 8‐yr monitoring plan of a Kentish plover population showed a linear increase in their breeding success as their breeding season increasingly overlapped with that of the black‐winged stilt. An experiment with artificial nests showed a significant increase in the number of exposure days (7 to 12) when these nests were within close distance of black‐winged stilt nests. Overall, our results showed that saltpans are an important alternative breeding habitat for the Kentish plover, especially for the maintenance of mixed species colonies.

Susceptibility of Carrion Crows to Experimental Infection with Lineage 1 and 2 West Nile Viruses.

West Nile virus (WNV) outbreaks in North America have been characterized by substantial die-offs of American crows (Corvus brachyrhynchos). In contrast, a low incidence of bird deaths has been observed during WNV epidemic activity in Europe. To examine the susceptibility of the western European counterpart of American crows, we inoculated carrion crows (Corvus corone) with WNV strains isolated in Greece (Gr-10), Italy (FIN and Ita09), and Hungary (578/10) and with the highly virulent North American genotype strain (NY99). We also inoculated American crows with a selection of these strains to examine the strains' virulence in a highly susceptible bird species. Infection with all strains, except WNV FIN, resulted in high rates of death and high-level viremia in both bird species and virus dissemination to several organs. These results suggest that carrion crows are highly susceptible to WNV and may potentially be useful as part of dead bird surveillance for early warning of WNV activity in Europe.

High begging intensity of great spotted cuckoo nestlings favours larger-size crow nest mates

In nests of birds parasitized by a larger non-evicting brood parasite, host chicks typically are at disadvantage in competing for food and often starve. However, when host chicks are larger, they may benefit from the presence of the parasite, which contributes to the net brood begging signal but cannot monopolize the food brought to the nest. Here, we show that, despite a higher begging intensity, great spotted cuckoos (Clamator glandarius) did not outcompete larger size carrion crow (Corvus corone corone) nestlings. Furthermore, cuckoos’ exaggerated begging allowed crow nest mates to decrease their begging intensity without negative consequences on food intake. Assuming an energetic cost to chicks of begging intensely, our results suggest that crow chicks sharing the nest with a cuckoo may obtain an advantage that should be weighed against the loss of indirect fitness due to parasitism.

Predators and Predation Rates of SkylarkAlauda arvensisand WoodlarkLullula arboreaNests in a Semi-Natural Area in the Netherlands

Predation is a major cause of breeding failure in bird species with open nests. Although many studies have investigated nest predation rates, direct identification of nest predators is sporadic, especially in (semi-)natural habitats. We quantified nest success and identified nest predators in a population of Skylarks Alauda arvensis and Woodlarks Lullula arborea breeding in a protected semi-natural area dominated by heathland and different succession states of grassland on nutrient-poor soil in The Netherlands. We monitored 54 nests by means of continuous video surveillance to determine survival times and predators, and monitored another 44 nests without a camera. Fates of the 58 (40) Skylark (Woodlark) nests were: fledging 41 (27), depredation 13 (12), egg desertion 1 (0) and nestling death 3 (1). The overall nest success of all monitored nests (58 (40), Mayfield estimate) was 33% (22%; all mortality factors considered) or 43% (25%; only depredation). Predators of Skylark nests were Red Fox Vulpes vulpes (5), Carrion Crow Corvus corone (1) and European Adder Vipera berus (1). Woodlark nests were depredated by Carrion Crow (2), Eurasian Jay Garrulus glandarius (1) and Red Fox (1). Results suggest that the main nest predators might differ between the two co-occurring lark species; Skylark nests located in more open sites were preyed upon mainly by Red Fox, while the main predators of Woodlark nests, located generally closer to trees, are corvids.

Avian blood induced intranuclear translocation of STAT3 via the chicken leptin receptor.

Leptin is a multi-functional adipokine in vertebrates. The leptin gene and protein are found in many vertebrates; however, the existence of leptin in birds remains controversial. Here we detected leptin-like activity in avian blood using chicken leptin receptor (chLEPR) and green fluorescent protein (GFP)-fused chicken signal transducer and activator of transcription (chSTAT3) co-expressed in CHO-K1 cells (CHO-chLEPR/STAT3). We validated that rat serum specifically induces intranuclear migration of GFP-fused chSTAT3 (GFP-chSTAT3) in CHO-chLEPR/STAT3 cells, but not in CHO-K1 cells expressing GFP-STAT3 (CHO-chSTAT3) before testing the avian blood samples. Blood of chickens (Gallus gallus), wild jungle crows (Corvus macrorhynchos), and carrion crows (Corvus corone) accumulated the GFP signal into nuclei, and frequency varied in each blood sample. Western blotting showed that chicken and crow blood samples specifically phosphorylated GFP-chSTAT3 in the chLEPR-transfected cells. These results indicate that avian blood contains a leptin-like molecule that specifically binds to LEPR, suggesting that the leptin system is conserved across all vertebrate classes.

Impacts of predator abundance on red grouse Lagopus lagopus scotica during a period of experimental predator control

During a nine‐year study manipulating predator abundances, post‐breeding numbers of red grouse Lagopus lagopus scotica increased initially in response to experimentally reduced levels of key predator species (i.e. red fox Vulpes vulpes, carrion crow Corvus corone, stoat Mustela erminea and least weasel M. nivalis), but subsequently declined whilst predator control continued. Raptors, which were not controlled, were also present and may have influenced grouse demography. Our study examines the relative importance of controlled predators and raptors on grouse breeding success and survival. Raptor abundance did not differ between periods of predator control and periods of no predator control. However, during the breeding season, the survival of adult grouse was negatively correlated with the abundance of both raptors and controlled predators. Within the group of controlled predators, the strongest effects on red grouse adult survival were attributed to small mustelid abundance. Grouse breeding success was negatively correlated with the abundance of controlled predators, particularly carrion crows; however, no significant effect of raptor abundance was detected.

Hen harriers on a Scottish grouse moor: multiple factors predict breeding density and productivity

Summary Predator density and productivity can be influenced by ecological and anthropogenic factors. Given the controversy over predators impacting on prey of economic and conservation importance, it is essential that these relationships are understood to provide a sound scientific basis for their conservation and management. We compared numbers and productivity of hen harriers Circus cyaneus, a protected specialist predator of conservation importance, in relation to a change in generalist predator management at Langholm, a moor managed for red grouse Lagopus lagopus scoticus shooting in southern Scotland between 1992 and 2007. During 1992–1999, the moor was managed for grouse and keepers legally controlled predators, thereafter keepering ceased. Following full protection being given to nesting harriers, their numbers increased from two breeding females in 1992 to 20 in 1997, when predation by harriers limited numbers of grouse available for shooting. After grouse management stopped in 1999, carrion crows Corvus corone and red foxes Vulpes vulpes increased and numbers of female harriers dropped to below five from 2002 onwards. Numbers of breeding harriers were negatively correlated with meadow pipit Anthus pratensis, crow, and July grouse abundance during the keepered period and positively with spring grouse abundance. Harrier clutch size was positively correlated with vole abundance. Harrier clutch survival and productivity were higher when the moor was keepered. Predation by foxes was the main cause of harrier breeding failure. Synthesis and applications. We consider this study to be the first that quantifies how control of generalist predators as part of grouse moor management can benefit harrier productivity. This adds to the importance of finding ways to ensure that grouse moors are managed for harriers, but are still economically viable. If techniques can be devised and put in place to reduce the impact of harriers on grouse, then the control of generalist predators may be viewed as a more acceptable component of conservation management for ground‐nesting birds.

Breeding Biology and Fledgling Survival in a Carrion CrowCorvus coronePopulation of Southern Spain: A Comparison of Group and Pair Breeder

Abstract. Cooperative breeding is not common among birds, although its frequency is relatively high within the Corvidae family. We study the effect of group breeding on the reproductive biology of the Carrion Crow Corvus corone, a species that was usually described as non-cooperative. Our study population is located at the southern limit of the distribution of the species, which confers special characteristics to its breeding biology. Early breeders had a significantly larger clutch size and produced a higher number of fledglings. Replacement clutches were very rare and always unsuccessful, contrary to what happens in other European Carrion Crow populations. More than half of the breeding attempts (66.1%) in our study area showed cooperative breeding but it had only a significant effect on laying date — group-breeding females laid eggs significantly earlier than did pair-breeding females. We also explored brood parasitism by Great Spotted Cuckoos Clamator glandarius on the reproductive success of Carrion ...

Carrion Crow Corvus Corone Breeding In Lubuskie Province, W Poland

Abstract In 2013, a clutch of the Carrion Crow Corvus corone was recorded in the Warta Mouth National Park, western Poland. In April and the first half of May a female incubating two and later four eggs was observed. In mid-May the nest was found empty, indicating that the failure occurred during incubation or the early nestling stage. No male was observed until that time. However, two Carrion Crows were recorded near the nest after the breeding failure, which indicates that it was indeed a breeding attempt made by a homogamic (“pure”) Carrion Crow’s pair. This is the first case described for the Lubuskie Province and the second for Poland in the last 200 years.

Comparative Phylogeography of Two Crow Species: Jungle Crow Corvus macrorhynchos and Carrion Crow Corvus corone

The jungle crow Corvus macrorhynchos Wagler, 1827, and the carrion crow Corvus corone L., 1758, are two closely related species with similar ecological requirements that occupy wide distribution ranges in the Palearctic. We studied patterns of their genetic variation by using sequences of the mitochondrial cytochrome b gene. Corvus macrorhynchos demonstrates a low level of variation and differentiation throughout its range, except for a highly diverged population of Cheju Island (Korea). The haplotype network shows two haplogroups. The island group comprises populations of Sakhalin, Hokkaido, Honshu, and Kyushu, while the haplotypes of Taiwan and Ryukyu Islands proved to be closer to the mainland group, which also includes populations from the Primorye, Khabarovsk, Amur, and Magadan regions in the Russian Far East. This pattern allowed us to develop a phylogeographic hypothesis regarding the two modes of settling of the island populations. Concerning C. corone, the presence of two distinct haplogroups was confirmed within the range of C. c. orientalis. Both haplogroups are found within the same populations in Kamchatka and North Sakhalin, which implies secondary contacts there. Populations of C. corone are found to be rather stable in the western parts of its range, while in the Far East populations experienced recent growth, as was observed for C. macrorhynchos in general. The two species appear to have passed through different evolutionary scenarios.

Exploring the relationships between wader declines and current land‐use in the British uplands

Capsule Declines of upland waders were associated with habitat cover, forest edge exposure, grouse moor management intensity and crow abundance. Aims To explore whether changes in the abundance of five wader species in the uplands correlate with the three key hypotheses proposed for their declines. Methods Using data from repeat upland bird surveys, we examined at two spatial scales (region and plot) if population changes correlate with vegetation cover, forest edge exposure, grouse moor management intensity or crow abundance. Results For Northern Lapwings Vanellus vanellus and Eurasian Curlews Numenius arquata, there was an association between declines and broad‐scale vegetation cover; declines being greatest on heather‐dominated plots. Exposure to forest edge was associated with declines of European Golden Plovers Pluvialis apricaria and Common Snipe Galinago galinago at the plot scale, and of Northern Lapwings at the regional scale. More intensive grouse moor management was associated with lower declines in Northern Lapwings at both the plot and regional scale, but with greater declines in European Golden Plovers at the plot scale. Northern Lapwings also declined most on plots with the highest Carrion Crow Corvus corone abundance. Conclusion These analyses represent the first attempt to assess empirically the balance of evidence for different broad‐scale land‐use and habitat‐related drivers of upland wader population declines, providing pointers to their respective roles in driving these declines.