Crow Corvus Corone Research Articles

Winter Roost Preferences of Crows in Beijing City.

During the winter season, an extensive population of crows (predominantly the carrion crow Corvus corone) seek refuge in Beijing's urban landscapes for roosting, subsequently generating noise and droppings that adversely affect the quality of life of residents. This study elucidates the selection criteria employed by crows in Beijing's urban areas for roosting sites. Drawing upon historical records and the outcomes of our survey, we observed a remarkable consistency in the selection of roosting locations by crows over time, with the same locations being preferentially chosen across different years. We also conducted a quantitative analysis of the habitat characteristics associated with the crow roosting sites. We discovered that crows demonstrate a preference for roosting sites situated in proximity to human structures, particularly towering buildings, which are often adjacent to broad roads. By understanding the factors that influence the selection of roosting sites by crows, policy-makers and urban planners can devise targeted interventions aimed at mitigating conflicts between humans and crows.

Trait‐mediated indirect effect involving a chain of learning in agroecosystems

AbstractAn increase in predation risk triggers a trait response of prey, which alters the interactions between the prey and other species, ultimately affecting other species in the ecosystem. Such predator‐driven trait‐mediated indirect effects (TMIEs) may have been shaped by long‐term evolutionary processes involving the organisms involved, but learning may also be important, especially in contemporary ecosystems experiencing repeated biological invasions. The apple snail Pomacea canaliculata is an important introduced pest of rice, Oryza sativa. Recently, the carrion crow Corvus corone has been found to prey on this species only in some areas, suggesting that learning is involved in this predation. In addition, apple snails can learn to escape from predators and exhibit predator‐specific responses. Thus, the “chain of learning” by the crow and the snail may shape novel TMIEs in the rice ecosystem. We conducted field and mesocosm experiments to test this hypothesis. In the field experiment, we simulated predation by crows in rice fields and investigated the behavior of apple snails. The snails exhibited escape behaviors in response to the simulated predation, and both the proportion of individuals showing the escape response and the degree of escape response were greater in fields with predation by crows than those without predation. In the mesocosm experiment, apple snails from fields with and without predation by crows were separately introduced into mesocosms simulating rice fields, and the behaviors of the snails and the number of remaining rice plants were recorded for 16 days at three levels of predation risk (daily, every 4 days, or no predation). Both the presence/absence of predation in the collection fields and simulated predation affected the escape responses of the snails. Moreover, damage to rice was more severe in mesocosms containing snails from fields without predation than those containing snails from fields with predation. These results suggest that the “chain of learning” causes TMIEs in agroecosystems.

Small-scale forest restoration in peri-urban areas provides immediate benefits for birds

Summary Forests of urban/suburban areas are being increasingly restored, but before/after-control/impact studies addressing effects on biodiversity in peri-urban forest restorations are virtually lacking. Using a before/after-control/impact (BACI) design, we explored the effects on birds (commonly used as indicators for restoration impacts) of small-scale restoration interventions in 2019 targeting residual forests north of Milan, in the largest Italian conurbation, with trees and shrub planting around existing patches or in formerly cultivated areas. Birds were surveyed in 2018, 2019, and 2021, at 20 intervention and 20 control sites. We evaluated the short-term effects of restoration by analysing changes in avian communities (i.e. richness, richness and abundance of forest specialists, single species’ abundance), considering the effect of year and intervention (i.e. before/during/after intervention). Species richness of breeding birds was largely unaffected by on-going interventions, while it was positively related to concluded restoration. The abundance of five individual species varied according to restoration: on-going interventions had positive effects on two species, Common Blackbird Turdus merula and Hooded Crow Corvus corone cornix, and negative effects on Barn Swallow Hirundo rustica, while concluded restoration positively affected two species, Common Blackbird Turdus merula again, and the forest specialist Marsh Tit Poecile palustris. Even small-scale interventions in peri-urban areas may provide tangible benefits to breeding birds in the short term: peri-urban forest restoration could contribute to biodiversity conservation.

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.

Impact of Nest Predators on Migratory Woodpigeons Columba palumbus in Central Europe — Breeding Densities and Nesting Success in Urban Versus Natural Habitats

The Woodpigeon Columba palumbus is a species generally increasing in numbers in most of its populations, including the urban population, which, two centuries after its emergence, is still expanding across the European Lowland. New for the species is a tendency to form dense breeding aggregations in suitable urban parks, with a corresponding slower increase in some other towns. This trend was driven by the presence of important nest predators, mostly Hooded Crows Corvus corone. Another factor involved was access to open farmland within the economic range of feeding flights. Nesting success (1st brood) in urban habitats free of important predators was up to 50–77% but it fell to only 3–7% when predators appeared. Consequently, some urban populations of the Woodpigeon went into a phase of decline. In the farmland and secondary woods, the nesting success was also variable, ranging between 12 and 42% for unknown reasons. Safe urban populations produced 4–5 times more offspring per pair per season, yet their expansion was rather slow. Therefore, the urban overproduction may contribute to an increase in the total species abundance, owing to (deduced) overspill of recruits to the poorly reproducing subpopulation in the countryside. Alongside other factors such as amelioration of winter conditions and changes in agriculture, this would contribute to the documented growth of the whole population of the species. The shortage of firm data on the pristine breeding success (from extensive natural forests) remains the main obstacle to better understand the population dynamics of this migratory species.

Crows control working memory before and after stimulus encoding

The capacity of working memory is limited and this limit is comparable in crows and primates. To maximize this resource, humans use attention to select only relevant information for maintenance. Interestingly, attention-cues are effective not only before but also after the presentation of to-be-remembered stimuli, highlighting control mechanisms beyond sensory selection. Here we explore if crows are also capable of these forms of control over working memory. Two crows (Corvus corone) were trained to memorize two, four or six visual stimuli. Comparable to our previous results, the crows showed a decrease in performance with increasing working memory load. Using attention cues, we indicated the critical stimulus on a given trial. These cues were either presented before (pre-cue) or after sample-presentation (retro-cue). On other trials no cue was given as to which stimulus was critical. We found that both pre- and retro-cues enhance the performance of the birds. These results show that crows, like humans, can utilize attention to select relevant stimuli for maintenance in working memory. Importantly, crows can also utilize cues to make the most of their working memory capacity even after the stimuli are already held in working memory. This strongly implies that crows can engage in efficient control over working memory.

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.

Динаміка популяцій воронових і їхній вплив на мисливську фауну Луганської області

Досліджено багаторічну (1983–2013 рр.) динаміку щільності популяцій птахів родини Воронових (Corvidae) у мисливських угіддях Щетівського лісництва Іванівського ДЛМГ Луганської області. Щільність популяцій визначено методом маршрутного обліку без обмеження смуги огляду та перераховувано на 1 км2 за середньою дальністю виявлення птахів. Встановлено, що за 30 років щільність популяції ворона в регіоні досліджень збільшилася в 11,5 раза – від 0,1 до 1,15 екз./км2, щільність популяції ворони сірої зменшилася в 11,1 раза – від 3,4 до 0,3 екз./км2, сороки – у 2,4 раза, граків і галок – у 9,2 та 2 рази відповідно, сойки – в 1,6 раза. Визначено тісний від'ємний зв'язок між щільністю популяцій ворона та інших досліджених видів воронових, найтісніший – між щільністю популяцій ворона та ворони сірої, з огляду на близьку екологію цих двох видів із перевагами ворона як більш великого та агресивного виду. Проаналізовано залежність щільності популяцій ворона, ворони сірої, сороки, грака, галки та сойки від особливостей живлення, місць поселення, шкоди для об'єктів полювання та антропогенних чинників (зміни системи обробітку ґрунту, структури посівних площ, ліквідації тваринницьких комплексів тощо). Рекомендовано спростити одержання дозволів на відстріл ворона, який завдає великої шкоди об'єктам полювання (крижню та іншим качкам, фазану, куріпці сірій та зайцю-русаку).

Catching crows: seasonality, techniques and the influence of social behaviour

ABSTRACT For most research on birds in the wild, catching and marking of individuals is essential. Corvids may be difficult to catch due to their neophobia and good learning abilities; moreover, different catching methods may target specific social classes. We investigated the success of two different catching methods, Ladder trap and Larsen trap, over the course of a five-year research program on crows (Corvus corone, C. cornix and their intergrades) conducted in Vienna, Austria. Ladder traps were highly effective in catching non-breeders and migrants whereas Larsen traps were useful for catching territorial birds. Catching success with Ladder traps was highest during the breeding season and shortly thereafter, but only if catching efforts were restricted to this period. If the traps were active year round, catching success declined, possibly because crows became trap shy. The number of crows present was not significantly correlated with catching success. Crows that entered the traps together tended to be observed foraging together, indicating that the traps probably represent foraging opportunities that are shared by associated individuals. Taken together, these findings may provide valuable hints to researchers planning to catch these species.

Threats and the active protection of birds in a riverbed: postulates for the strategy of the preservation of the middle Vistula River avifauna

Over the past 34 years, threats to Charadriiform birds inhabiting islands in the Vistula riverbed, mainly gulls, terns and plovers, have changed considerably. While in 1985-1994 the main risks for their breeding were found to be flood waters, predation by the hooded crow Corvus corone cornix and the Eurasian magpie Pica pica, as well as, locally, uncontrolled livestock grazing, in 2005-2014 they were primarily predation pressure from the American mink Neovision vision and the red fox Vulpes vulpes and massive outbreaks of black flies Simuliidae. These threats led to a reproductive outcome of nearly zero and increased the mortality of adults in their breeding areas. As a result, there was a sharp decline in numbers of the majority of gull, tern and plover species nesting there. In 2015-2018, apart from mammalian predation, key threats included the pressure of feral cats and dogs and the growing presence of people on the islands. In a situation that may lead to the extinction of first the mew gull, Larus canus, and later other species of birds, in 2005-2006, we began the active protection of endangered species on the middle Vistula River islands. This effort included (a) reducing the number of American minks and red foxes, (b) neutralising the presence of predators and livestock at the nesting sites with electric fences and the use of incubators and dummy eggs and (c) restoration of the nesting habitat, as well as, in the case of mew gulls, (d) increasing the genetic diversity within colonies. The most important demand is the conducting of the active protective measures in a comprehensive way and continuously for at least five years (until 2023), optimally throughout the decade (2019--2028). In addition, it will be also necessary to carry out wildlife monitoring in this area. The other important task for the coming years will be to oppose plans for extensive engineering in the middle section of the river, which will irreversibly destroy this unique ecosystem.

Birds trapped in telephone wiring system

[Six cases of birds trapped in telephone wires or in structures connected to telephone wires were signaled in the areas of Turin and Novara (Piedmont, N. W. Italy). The birds stayed hanging fatally either by chance or during a trophic activity. The species involved in the described episodes are five, but become eight when added to the ones subjects of previous signaling: Little bitten Ixobrychus minutus, Grey heron Ardea cinerea, Moorhen Gallinula chloropus, Barn owl Tyto alba, Little owl Athene noctua, Robin Erithacus rubecula, Starling Sturnus vulgaris, Hooded crow Corvus corone cornix.]
 [Article in Italian]

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.

Blood parasites in hooded crows (Corvus corone cornix) in Northwest Italy.

Haemoparasites and their effects on hooded crows (Corvus corone cornix) are poorly studied. The aims are to evaluate the prevalence of Haemoproteus spp./Plasmodium spp. or Leucocytozoon spp., to correlate this with gross and histopathological findings, and to investigate the association among infection and geographical origin, age, gender, parasite distribution and prevalence among organs. Hooded crows (n = 47) were collected within a regional culling programme from 3 districts in the province of Turin (Italy) and subjected to necropsy. Histological and molecular analyses were carried out on some tissues. Leucocytozoon spp. was detected in 46 crows (97.9%) by polymerase chain reaction (PCR), whereas 28 birds (59.6%) were found to be positive for Haemoproteus spp./Plasmodium spp. The distribution of parasites in several organs varied significantly, showing that Leucocytozoon spp. is ubiquitous in organs in contrast with Haemoproteus spp./Plasmodium spp., which have a specific predilection for spleen and lungs. The prevalence of Haemoproteus spp./Plasmodium spp. also differed significantly among the crows captured in the areas of the study. The high prevalence of haemoparasites emphasizes the success of ornithophilic vectors and the susceptibility of this species to infection. Differences in prevalence among the sites are probably due to orographic features of the areas, variations in vector species and density, or to crow population size or structure. In spite of the high infection rate, no gross and histological lesions were found. This finding further suggests an evolutionary adaptation between crows and avian blood parasites.

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.