White Stork Research Articles

From sky to ground: decoding migratory bird’s habitat selection along the multi-scale sequence

ContextMigratory birds select habitats by observing landscape patterns at different scales as they descend from higher elevations, weighing habitat availability. Understanding how this selection process operates at multiple scales and how decisions at different scales interact is crucial for identifying the optimal scale for efficient habitat conservation.ObjectivesWe aimed to investigate the regularity of changes in migratory birds’ habitat selection in response to landscape variables over multi-scales, using the Oriental White Stork (Ciconia boyciana) as an example.MethodWe developed Scale Response Models and Habitat Selection Models using a sequence of nine scales (5–200 km) within the East Asian-Australasian Flyway to evaluate the stork’s scale-sensitivity and assess the change of explanatory power of landscape variables across scales at different periods.ResultScale-sensitivity of storks was highest during the wintering period. The explanatory power of the suitable habitat indicator is higher at larger scales, but decreases with decreasing scale; while the opposite is true for the unsuitable habitat indicator. At large scales, wetland indicators dominated in breeding period, while water indicators dominated in other periods; at smaller scales, unsuitable habitat indicators had stronger impacts in wintering period.ConclusionsWe revealed a nested relationship in multi-scale habitat selection among storks: “benefit-tendency” decisions at larger scales provide context and constraints; “risk-avoidance” decisions at smaller scales determine settlement. Due to internal and external factors, migratory birds displayed different scale-sensitivities and landscape preferences across periods. Our findings highlight the scale-dependence of organisms’ behavior and landscape characteristics, providing guidance for multi-scale habitat conservation.

Microplastic accumulation in various bird species in Turkey.

Plastic pollution constitutes one of the major environmental problems of our time, and in recent years, it has emerged as a significant threat to the environment and to various organisms, including bird species. In this context, this study, which provides the first data in Türkiye, aimed to determine the level of microplastic (MP) pollution in 12 bird species (Eurasian buzzard; short-toed snake-eagle; white stork; northern long-eared owl; common barn-owl; ruddy shelduck; Eurasian eagle-owl; scarlet macaw; common pheasant; Indian peafowl; common kestrel; and gray parrot). The results indicate that MPs were detected in 50% of the specimens (n = 20), with an average of one MP/item per individual. With an average of three MPs per individual, the short-toed snake-eagle was found to be the species with the highest MP accumulation. Fibers (range: 51-534 µm) were the most common type of plastic found in the gastrointestinal tract of birds, with ethylene vinyl acetate and navy blue being the most common polymer type and color, respectively. It was also found that the abundance of MPs increased with the weight of specimens, contributing to the hypothesis that there is a correlation between the size/weight of animals and increased levels of MP accumulation. These findings highlight the impact of plastic pollution on birdlife and the need for further monitoring to assess the ecological impact of pollution.

Do agricultural practices on meadows reduce or increase flight initiation distance in the white stork ciconia ciconia?

Do agricultural practices on meadows reduce or increase flight initiation distance in the white stork ciconia ciconia?

A Roadmap for the Future Research of the White Stork Ciconia ciconia Population in Poland

A Roadmap for the Future Research of the White Stork Ciconia ciconia Population in Poland

White Storks (Ciconia ciconia Linnaeus, 1758) in Georgia: Current distribution and population status

This study provides an analysis of the current status, population trends, and distribution of White Storks (Ciconia ciconia) in the Republic of Georgia. Findings from our most recent survey in 2024 revealed a 40% increase in the number of White Stork nesting pairs in settlements previously surveyed during the 2018–2020 census. However, this increase was not statistically significant. The 2024 survey expanded its scope to include 36 additional settlements that had not been surveyed or reported in prior assessments, resulting in the documentation of 55 new nesting pairs within 22 settlements. Among the 23 settlements surveyed in both 2018–2020 and 2024, fluctuations in the number of White Stork nesting pairs were observed in 14 settlements, with a general increase and slight declines noted in four settlements.

Presence of Borrelia Spirochetes in White Stork (Ciconia ciconia), White-Tailed Eagle (Haliaeetus albicilla), and Eastern Imperial Eagle (Aquila heliaca): Hospitalized in a Wild Bird Hospital and Sanctuary (Hortobágy, Hungary).

Wild birds across the globe can carry the causative agent of avian borreliosis, Borrelia anserina, and that of human Lyme borreliosis, Borrelia burgdorferi sensu lato in the ticks attached to them. Currently, only limited proof exists for the presence of these pathogens in samples taken from living wild birds, carried by the birds as a reservoir, without symptoms. We investigated blood samples of large-bodied wild birds admitted to a bird hospital, where basic clinical symptoms were recorded. Thirty-six blood samples were collected from them, according to the DualDur kit methodology, and investigated using dark-field microscopy to search for spirochetes. Five of the samples were also investigated by immunofluorescence microscopy to identify Borrelia burgdorferi. Since the main reason for admittance to the hospital was a physical injury, no significant symptoms were observed regarding a current Borrelia infection. Out of the sixteen birds of prey, eleven (68%) were infected with spirochetes, and fifteen out of twenty storks (75%) were also infected with spirochetes, without major symptoms. All five samples investigated using immunofluorescence were confirmed to contain the human pathogenic Borrelia burgdorferi sensu lato. Thus, direct investigations of the blood of wild birds may show the asymptomatic prevalence of Borrelia in the wild bird population.

How nesting support type interacts with vegetation greening and distance to nest trees of mixed-species to predict white stork nest density in a Mediterranean capital

White Stork (WS) ( Ciconia ciconia (Linnaeus, 1758)) ranks among the most common breeding birds in many Mediterranean cities, underscoring the importance of studying nest densities, particularly when populations are increasing. In this study, conducted in Rabat (Morocco), we aimed to investigate the effects of coloniality, landscape composition, and space to identify the best predictors of variation in the number of WS nests per nest support using generalized linear mixed models. The results revealed significant interactions between the type of support (trees vs. pylons) and normalized difference vegetation index (NDVI) as well as between the support type and the distance to the nearest support occupied by WS and Cattle Egret (CE) ( Bubulcus ibis (Linnaeus, 1758)) nests. A high number of nests are associated with an NDVI increase around pylons, while such an effect is insignificant around trees. In contrast, a high number of WS nests are noted close to supports occupied by both WS and CE nests, whereas in pylons, this number is recorded far away from them. The implementation of a scientific monitoring system is crucial for determining, at a defined time step, the direction and strength of relations between WS and CE populations in Rabat.

Assessing cost-effectiveness of dissuasion techniques targeting waterbirds in rice fields

In a scenario of global wetland loss, rice fields are becoming vital habitats for waterbirds, often offering abundant and predictable food resources. However, the increasing presence of waterbirds in rice fields is exacerbating human-wildlife conflicts, as birds are seen as pests by farmers due to the damage they perceive the birds inflict to the crops. To tackle this situation, farmers use dissuasion methods like propane gas cannons, but its effectiveness in reducing damage is often not quantified. In this study we evaluate the cost-effectiveness of propane gas cannons in deterring waterbirds from rice fields and test if there is a correlation between bird abundance in a given field during rice growth and rice yield in the same field. Waterbird counts were conducted before and after dissuasion actions targeting Glossy ibis and White stork in a major rice production area in Portugal. To assess the potential magnitude of damage reduction gained through dissuasion, we estimated the time elapsed between dissuasion events and the reestablishment of bird numbers in the disturbed fields. The economic cost of dissuasion was compared with the estimated gains from reduced damage. Results showed that on average, waterbird numbers recovered ca. 30 min after dissuasion, leading to an estimated 0.78% reduction in crop damage. The final yield of rice production was modelled considering all gains and costs involved in dissuasion actions in relation to an increase in dissuasion efforts for 11 scenarios of potential waterbird damage (0–20%). For dissuasion to be cost-effective, waterbirds would need to destroy at least 17% of the crops, far more than any damage previously recorded in Europe. Also, we found that the abundance of waterbirds in a rice field does not affect rice yield. We suggest that efforts to reduce damage should shift to more cost-effective and environmentally friendly methods, such as diversionary fields or economic compensations to farmers. This can enhance the economies of rice-dependent countries and reduce conflicts, ultimately reconciling rice agriculture with biodiversity conservation.

One Health bottom-up analysis of the dissemination pathways concerning critical priority carbapenemase- and ESBL-producing Enterobacterales from storks and beyond.

'One Health' initiatives to tackle the rising risk of antimicrobial resistance (AMR) have flourished due to increasing detection of Enterobacterales producing extended-spectrum beta-lactamases (ESBLs) and carbapenemases (CPs). This study aimed to conduct an in-depth holistic analysis of Escherichia coli (Ec) and Klebsiella pneumoniae (Kp) isolates recovered from landfill-foraging white stork faecal samples and clinical isolates from a nearby hospital. Faecal samples (n = 211) were collected from storks foraging at two landfills in Spain. Ec/Kp stork isolates were recovered on selective media and whole-genome sequencing (WGS), together with isolates obtained from the nearby hospital. These genomic data were compared with public genomes from different contexts (clinical, environmental, or animal hubs) to understand global transmission dynamics. A wide range of blaESBL/blapAmpC (blaCTX-M/blaSHV-12/blaDHA) were detected in 71 stork samples (33.6%), while blaCP (blaKPC/blaNDM/blaOXA-48/blaVIM) were identified in 28 (13.3%) samples. Clonal and plasmid transmissions were evidenced inside and between both landfills. Mapping against 10 624 public Ec/Kp genomes and from those of nearby hospital revealed that identical strains (<10 allelic differences with Ec-ST38/ST131 and Kp-ST512 lineages) and epidemic plasmids (full identity/coverage with IncN/blaKPC-2, IncF/blaKPC-3, IncX3/blaNDM-7, IncL/blaOXA-48) were found from clinical isolates in countries located along the storks' migration routes. Storks may be contaminated by bacterial isolates from a likely human origin and become non-human reservoirs of critical genes, which can be dispersed over long distances. Identifying strains/plasmids along the stork's routes that are identical or closely related to those described here opens new perspectives for large-scale research to understand the AMR transmission dynamics.

Spatio-temporal analysis of habitat suitability for the endangered oriental white stork (Ciconia boyciana) in the wetland ecosystem of northeast China

Human-induced habitat transformation often leads to habitat degradation and loss, impacting suitable habitats for endangered and rare species. This study was conducted to assess suitable habitats for the endangered oriental white stork in the wetland ecosystem of northeast China, to facilitate successful species-habitat conservation. The study incorporated field surveys, literature reviews, vegetation index calculations, eDNA for assessing prey abundance and land use and land cover classification for the years 2000, 2011, and 2022. A fuzzy logic-based habitat model was developed to map suitable habitats for the oriental stork. Generalized Linear Models (GLM) and Principal Component Analysis (PCA) were used to assess the influence of various environmental variables on habitat suitability changes. Roosting locations of the oriental stork were used as reference points to evaluate the impact of environmental factors on habitat suitability. The results indicate that 20% of the area is highly suitable for the stork, 73.4% is moderately suitable, and 5.6% is less or not suitable. Habitats near lakes and rivers, with low Normalized Difference Vegetation Index (NDVI) and high Normalized Difference Water Index (NDWI), are more suitable compared to areas close to roads and built-up zones. Prey abundance, particularly fish, is a crucial determinant of oriental stork presence and survival. Marshlands, swamps, and water bodies were identified as the most suitable habitats, as they interface with lotic and lentic ecosystems providing abundant prey for the storks. Our findings emphasize the importance of ongoing efforts to protect wetland ecosystems and habitats for endangered and rare bird species. Priority should be given to habitats identified as critical roosting areas for the oriental stork.

Ophthalmic examination findings in healthy white storks (Ciconia Ciconia)

In birds, vision plays an essential role in vital functions such as feeding and reproduction. In this study, it was aimed to determine the ophthalmic examination findings in healthy storks. A total of eleven healthy white storks were included in the study. Schirmer tear test 1 (STT-I), intraocular pressure (IOP) and ocular biometry were performed on both eyes of each stork. The mean STT-I values were 12±3.4 (right eye) and 11.9±3.14 mm/min (left eye), and the IOP values were 19±0.97 (right eye) and 18.85±0.73 mmHg (left eye). The mean ocular biometric values were as follows: anterior chamber depth, 2.30±0.18 and 2.29±0.13 mm, lens thickness 5.18±0.1 and 5.19±0.13 mm, vitreous body 11.72±0.25 and 11.82±0.34 mm, and pecten 7.94±0.34 and 7.9±0.37 mm of the right and left eyes, respectively. Knowledge of the normal value ranges in healthy white storks is necessary for the diagnosis of ocular diseases in this species. To the authors’ knowledge, this is the first study in which normal ophthalmic value ranges in healthy storks are described.

Bird deterrent measures at a landfill decreased the productivity of a dependent population of White Stork (Ciconia ciconia)

Landfills provide an abundant and predictable food source for avifauna. The energy and time that are saved because of landfill‐foraging have had positive effects on the distribution of bird breeding populations and their reproductive parameters. However, the proliferation of individuals coinciding with the appearance of landfills often increases human–wildlife conflicts and intensifies the contact between waste and the environment. In this context, a landfill in Madrid (Spain) implemented deterrent measures in 2021 aiming to reduce the influx of birds inside its facilities. This study aims to describe the effects that a reduction in the accessibility and availability of landfill food resources may have had on the surrounding breeding populations of White Stork Ciconia ciconia. For this purpose, the breeding parameters of three populations with different landfill use indices were analysed before and after the application of bird deterrent measures. The closest population, with the highest landfill use index, suffered a drastic reduction in fledgling productivity during the breeding season with bird deterrent measures. On the other hand, a drought during one of the breeding seasons negatively affected the productivity of the populations that relied partially and completely on natural food resources (located at medium and long distance from the landfill, respectively). Landfill‐foraging might have mitigated the consequences of the natural food scarcity caused by this drought, even with the application of bird deterrent measures. Overall, our results show the potential negative impact of bird deterrent measures on populations dependent on landfill food, and highlight the importance of assessing the effect of these techniques beyond the site to determine their appropriateness. Due to the imminent closure of landfills and the expected worsening consequences of climate change, monitoring programmes should be established to determine the long‐term effects of bird deterrent measures and unusual environmental conditions on White Stork populations.

Re-emergence of Bagaza virus in wild birds from southern Spain

Bagaza virus (BAGV; Orthoflavivirus bagazaense) is an emerging vector-borne flavivirus affecting avian species with severe implications for animal health, and whose zoonotic potential has also been suggested. The aim of the present study was to monitor the epidemic outbreak of BAGV in wild birds from Spain in 2021. BAGV cases were confirmed in game bird species, including red-legged partridges (Alectoris rufa) and common pheasants (Phasianus colchicus) from 24 hunting areas. Suspected cases (clinical signs and/or mortality compatible with BAGV infection but without molecular confirmation) were also detected in 11 additional hunting areas. The outbreaks showed a seasonality mainly restricted to July and August. Estimated morbidity [25.8 % (95 %CI: 11.3–40.3) in partridges and 8.7 % (95 %CI: 0.0–18.0) in pheasants] and mortality rates [27.3 % (95 %CI: 12.5–42.1) in partridges and 13.0 % (95 %CI: 1.9–24.1) in pheasants] were found in the affected hunting areas. In addition, 215 non-game birds belonging to 46 different species were sampled by passive surveillance upon admittance to rehabilitation centres during 2021. BAGV infection was detected for the first time in green woodpecker (Picus viridis), spoonbill (Platalea leucorodia), white stork (Ciconia ciconia) and cynereous vulture (Aegypius monachus), expanding the host range of this emerging pathogen. In contrast to other species, game birds showed distinct BAGV related lesions, primarily myocarditis and encephalitis in addition to inflammatory infiltrates and necrosis in the liver and kidney. Molecular analyses revealed a homology of 97.4–98.0 % and 92.5–92.7 % between the BAGV sequences obtained in the present study (492 bp) and those isolated in 2010 and 2019 in southern Spain, respectively. These results allow to hypothesise about the likely silent and endemic circulation of BAGV since 2010 in this European region, although repeated virus reintroduction from neighbouring territories cannot be ruled out. Our findings evidence the sanitary, ecological and conservation implications of the re-emerged BAGV for wild birds, also emphasising the need to increase surveillance for monitoring and early detection of flavivirus dynamics in high-risk areas.

Plastic ingestion in aquatic insects: Implications of waterbirds and landfills and association with stable isotopes

Wetlands provide numerous ecosystem services including freshwater purification. Nonetheless, their functionality is continuously impacted by many pollutants. Plastics are considered as an emerging threat for these ecosystems, but only recently have studies began to focus on plastic and microplastic (MP) contamination in wetlands, especially in biota. This study aims to investigate the abundance of MPs in two ubiquitous aquatic insect taxa (i.e. Corixidae (Hemiptera) and Chironomidae (Diptera)) collected in twelve zones within Mediterranean wetlands belonging to three basins located in Andalusia (south-west Spain). We compared MP contamination across basins and tested the proximity to landfills and presence of colonial waterbirds [i.e. white storks (Ciconia ciconia) and gulls (Larus michahellis and L. fuscus)] on MP abundance in aquatic insects. We also performed stable isotope analyses of nitrogen and carbon (δ15N and δ13C) to evaluate the potential association between MP abundance and isotopic values. We detected 571 suspected MPs (mostly blue fibers) in insects of different developmental stages (i.e., larvae, pupae, nymphs and adults). Polyesters and polypropylene were the most frequent polymers detected. The generalized linear mixed models indicated that MP abundance decreased with increasing distance from landfills; but it also increased in sites with birds that fed on landfills and roost in wetlands. When controlling for landfill effects, sites in the smallest basin (Guadalete) had lower MP contamination than those in Odiel-Tinto and the much larger (>15×) Guadalquivir. Moreover, we found a negative association between MPs items/g (or mean MPs) and 15N isotopes in adult corixids. Our findings showed that MP pollution is present in all the study areas, including strictly protected wetlands. The use of aquatic insects for biomonitoring of MP pollution can help identify priority areas for management actions to mitigate plastic pollution.

The Relationship between the Built World and the Nesting Habits of the European White Stork: A Case Study of Segovia, Spain C

The Relationship between the Built World and the Nesting Habits of the European White Stork: A Case Study of Segovia, Spain C

Fauna and flora listed in John Hooker’s manuscript ‘Synopsis chorographical of Devonshire’ (1599)

This paper introduces and comments on the animals and plants listed in a manuscript dated 1599 (the ‘Berry-Pomeroy Manuscript’), the ‘Synopsis chorographical of Devonshire’ by John Hooker of Exeter (1527–1601). Two hundred and seventy eight animals and plants were named, which is an unprecedented number for a local natural history text from sixteenth-century Britain. The animals mentioned include some of considerable interest like the wolf, bear, roe deer and red deer, polecat, black rat, white stork, Cornish chough and numerous freshwater fishes. Several cultivated varieties of domesticated fruit trees, in particular apples and pears, and other local specialities that are no longer known were also in Hooker’s list.

Prehistorical and historical occurrence and range dynamic of the Eurasian Spoonbill (Platalea leucorodia) and the White Stork (Ciconia ciconia) in Europe

AbstractThe Eurasian Spoonbill (Platalea leucorodia) and the White Stork (Ciconia ciconia) are emblematic birds of high conservation interest. This article examines their range history in Europe since the end of the last Glacial by analyzing subfossil bone finds of both species, mostly from archaeological excavations. It is shown that two thousand years ago, White Storks occurred exclusively in the territory of the Roman Empire, i.e. the northern border of their distribution ran along the Rhine and Danube rivers. The north-east part of the continent, with its high population density today, was only colonized in the last few centuries. The Spoonbill’s patchy occurrence in Europe today appears to be a typical distribution pattern for this species. The subfossil findings also do not indicate a large, closed distribution area for any phase of the last 10,000 years. Some of its distribution islands (e.g. those in the Netherlands) have existed for thousands of years.

DNA Prevalence of Eukaryotic Parasites with Zoonotic Potential in Urban-Associated Birds

Synanthropic birds might play an important role as reservoirs of many zoonotic endoparasites; however, little information is available on many parasites and their prevalence. Here, we use an approach based on targeted metagenomic detection through the use of DNA metabarcoding of faecal samples to screen for circulating parasites in alien parakeets (Myiopsitta monachus and Psittacula krameri) and urban landfill-feeding storks (Ciconia ciconia) and gulls (Larus fuscus). We focus especially on potentially zoonotic parasites, with the aim of better understanding the zoonotic risk that these birds’ faeces may pose. We detected a total of 23 genera of eukaryotic parasites: six fungi, three protists, five nematodes, two cestodes and seven trematodes. Among them, six stood out for their relevance to human health: Cryptococcus spp., Aspergillus spp. and Candida spp. (fungi); Cryptosporidium spp. (a protist); and Ascaris spp. and Halicephalobus spp. (nematodes). In parakeets, we detected Cryptococcus spp. and Ascaris spp., the latter being detected in 10–20% of the samples. In the White Stork and the Lesser Black-backed Gull, we found a high prevalence of Aspergillus spp. (in 15% and 50% of the samples, respectively) and Candida spp. (in 63% and 82% of the samples, respectively), and the presence of Cryptosporidium spp. in 10% of the samples. We detected Halicephalobus spp. in one gull sample (2%). Our results show that synanthropic birds may act as vectors and reservoirs of zoonotic parasites and their faeces could pose a risk to human health associated with the zoonotic parasites present in them. This should be taken into account when developing management plans for urban populations of these bird species.

Intersexual patterns of the digestive tract and body size are opposed in a large bird

The appropriate structure of the digestive tract is crucial for individual adaptation to ecological conditions. In birds, the length of the small intestine, responsible for food absorption, is generally believed to be positively correlated with body size. In this study, we investigated the variation in small intestine length in the White Stork (Ciconia ciconia), a monomorphic species without visible sexual dimorphism, but characterized by differing parental efforts, which can be reflected by the small intestine lengths between the sexes. We examined the relationship between small intestine length and body size within the sexes. Our findings show that male White Storks have significantly shorter small intestines than females, despite having larger body sizes than the latter. Furthermore, we found a significant relationship between body size and small intestine length, but it was of a different nature in the two sexes. Males exhibited a previously unreported phenomenon, whereby increasing body size was associated with shortening small intestines, whereas females exhibited the opposite pattern. These novel findings shed light on the anatomical adaptations of the digestive tract in birds.

Relationships between pesticides, polychlorinated biphenyls, blood parameters and oxidative stress of white stork Ciconia ciconia chicks in Poland

The white stork Ciconia ciconia is a bird species located at the top of the trophic pyramid in grassland and wetland ecosystems. This charismatic species is susceptible to pesticides and their environmental residues. In 2016, we collected blood samples from 114 white stork chicks across Western and Southern Poland. Chicks were sexed by molecular analysis and aged by development pattern. We studied the relationship between the concentration of pesticides (beta-HCH, heptachlor, aldrin, endrin, 4.4′-DDD, 4.4′-DDE and 4.4′-DDT) and of PCB in the chicks’ blood with blood morphology and biochemistry parameters in the blood. The mean (± SD) values of concentrations of above detection level pesticides were: for (1) beta-HCH 4.139 ± 19.205; (2) 4.4′-DDE 9.254 ± 91.491 and additionally (3) PCB 16.135 ± 44.777 ppb. We found negative relationships between beta-HCH and oxidative stress enzyme activity in the blood, between beta-HCH and leukocyte concentration and between 4.4′-DDE and catalase activity. We also found a positive relationship between the concentration of pesticides in blood and the age of chicks. Interestingly, we found a higher concentration of PCB in the blood of male stork chicks than in female stork chicks. We provide more evidence that the presence of pesticides in the environment can be a strong stress factor, shaping the health status of birds.