Black Stork Ciconia Nigra Research Articles

Low juvenile survival threatens the Black Stork Ciconia nigra in northern Europe

Summary Detecting factors causing the decline of wildlife populations provides essential knowledge for their effective conservation. Populations of Black Stork Ciconia nigra are decreasing in northern Europe; however, there are no detailed analyses of its survival, which frequently is a key demographic parameter affecting population dynamics in long-lived species. We used long-term data from re-sighted colour-ringed birds and satellite-tracked birds to estimate age- and sex-specific survival in a rapidly declining Black Stork population in the Baltic region at the northern end of the European range. Apparent survival (0.89) among colour-ringed birds older than one year was not significantly different from the previously reported estimates in Central Europe and the estimated real survival of GPS-tracked birds (0.77). However, the apparent survival of first-year (1y) birds was only 0.04, which is remarkably lower than earlier estimates in Central Europe. The real survival of GPS-tracked 1y birds was somewhat higher (0.11), but still much lower than estimates in other long-lived species. Apparent survival was three times lower in 1y females (0.013) than 1y males (0.045); this could be explained in part by a higher mean natal dispersal of females (189.1 km), compared with that of males (72.0 km), as well as by sex-specific mortality due to poor foraging conditions. There were no significant differences in apparent survival between the male and female storks older than one year. To better address the population decline, further research is needed to determine the factors causing low survival in young Black Storks, including the roles of food availability and climate change.

Birds of Kanetiya area - inventory, notable sightings, and overview of seasonal changes in reporting frequency of bird species in an unprotected area of Himachal Pradesh, India

Biodiversity of unprotected areas in the western Himalayan region is under threat. Despite this, it is poorly studied and documented. The citizen science platform eBird was used to record bird species of the unprotected Kanetiya area (Darbhog panchayat), Shimla, Himachal Pradesh from August 2019–2020. Reporting frequency using this data was calculated to represent an index of species abundance. This was calculated independently for each species across three seasons and reported as a metric that can be tracked over time. One-hundred-and-twenty-four (20% of the species from Himachal Pradesh) species of birds belonging to 13 orders and 43 families were recorded. Of these, 37 (30%) were recorded year-round and the remaining 87% (80%) were migratory. The checklist consisted of five species of high conservation concern and 22 species of moderate conservation concern. This checklist also provides insights into the distributions of some species whose ranges within India are not yet well defined (Northern Long-eared Owl Asio otus, Aberrant Bush Warbler Horornis flavolivaceus, Himalayan Owl Strix nivicolum) and into migration through this part of the Himalaya (Black Stork Ciconia nigra). Locals can be educated to upload short checklists for monitoring since they have helped the local forest department’s conservation efforts.

A review of the conservation status of Black Stork Ciconia nigra in South Africa, Lesotho, and Eswatini

Summary Across South Africa, Lesotho, and Eswatini, long-term citizen science atlas data have suggested concerning declines in the population of Black Stork Ciconia nigra. Unlike the Asian and European populations, the southern African Black Stork population is described as resident and is listed as “Vulnerable” in South Africa, Lesotho, and Eswatini. Here we report on surveys of historical nesting locations across northern South Africa, finding evidence for nest site abandonment and limited evidence of recent breeding. We undertook detailed species distribution modelling within a maximum entropy framework, using occurrence records from the BirdLasser mobile app. We cross-validated the models against information in the Southern African Bird Atlas Project (SABAP2) database, highlighting Lesotho as an important potential breeding area. Additionally, we used SABAP2 to assess population trends by investigating interannual patterns in reporting rate. Comparing current reporting rates with those from SABAP1 (1987–1992), we found that there has been a dramatic decrease. We noted that a large proportion of the population occurs outside the breeding range during the breeding season, suggesting a considerable non-breeding population, especially in the extensive wildlife refuge of the Kruger National Park. The slow declines observed might be indicative of a population which is not losing many adults but is failing to recruit significant numbers of juveniles due to limited breeding. Using densities derived from transect surveys, we used predictive models to derive estimates of breeding range carrying capacity and a population estimate, which suggested declines to numbers around 600 for this subregion. Minimising disturbance at breeding sites of this cliff-nesting species and improving water quality at key population strongholds are pathways to improving the status of the species in the subregion.

The avoidance of living in the vicinity of a top predator: the coexistence of the black stork and the white-tailed eagle in NE Poland

The black stork Ciconia nigra is a rare species of bird that inhabits old forests near wetlands. The early 21st century has brought a regress of its population in north-eastern Poland. We verified the assumption that an important reason for the observed changes was the colonization of the study area by white-tailed eagle Haliaeetus albicilla, because we observed a correlation between decreasing numbers of the black stork and increasing numbers of the eagle. Based on the long-term monitoring, we analyzed changes in the numbers and distribution of the black storks’ nests and compared the colonization of the study area by the white-tailed eagle in the most extensive forest complex in Poland. We found 42 occupied territories of storks and no eagles in 1989 within the study area. In 2019, there were just 23 stork pairs, but the population of eagles increased to 13. We found a correlation between the rate of decline of the black storks population and the increase in the white-tailed eagles. In the first half of study period, storks’ nests have been distributed randomly, after which they became clustered. The pattern of nests distribution was influenced by the increase in the population of the eagle over time, with this ensuring the aggregation of the nests of storks in places more distant from the nests of eagles. Similarly, the nearest neighbor distance of storks’ nests was dependent on distances from the nests of eagles and the shares of territory accounted for by forests. We surmise that changes in the population size of storks were induced mainly by the growth of population of eagles. Storks avoided occupying nests less than 4.6 km from the eagles’ nests. Our study suggests that the determining role can be played by fear of the predator. Overall, it must be concluded that the protection of top predators can affect other co-occurring species in unexpected ways.

Black Stork Back: Species distribution model predictions of potential habitats for Black Stork Ciconia nigra in Sweden

Increased understanding of the need to save endangered and locally extinct species has led to restoration or preservation of populations through reintroductions. Reintroduction of a species is worthwhile if the prerequisites for existence at the historical location have improved. Thus, background information about the habitat requirements of a target species is important for introduction programmes to be successful. The Black Stork Ciconia nigra was lost as a breeding species in Sweden during the 20th century, but recent observations and reports of potential breeding indicate that habitat conditions for Black Stork in Sweden may have improved. In this study, we used species characteristics and references to identify habitats in Sweden suitable for potential reintroduction of Black Stork. We identified several suitable areas in the former distribution range of this species in southern Sweden. Seven Swedish counties contained more than 18 % suitable habitat within their total area, with highest proportions in Jönköping County (25.8 %), Blekinge County (23.9 %), Västra Götaland County (22.1 %) and Kronoberg County (20.7 %). We suggest these areas to be made the primary targets for Black Stork reintroduction in Sweden.

New observations of four waterbird species in Algerian Sahara

AbstractThe range mapping and phenological status of four waterbird species was studied in Ghardaïa and El‐Ménéa regions between 2017 and 2021. Seasonal waterbird censuses were conducted throughout Ghardaïa and El‐Ménéa by individual counts or visual estimation. During these counts, four species were reported for the first time in this region, three passage visitors, European golden plover Pluvialis apricaria, black stork Ciconia nigra and Western Reef Heron Egretta gularis, and one winter stopover, common crane Grus grus. Observations on the species in Ghardaïa and El‐Ménéa regions are new for southern Algeria.

ASSESSING MERCURY POLLUTION USING BLACK STORK EGGSHELLS

Female birds whose bodies contain environmental contaminants produce eggs with shells that are likewise contaminated, making bird eggshells appropriate indicators for monitoring environmental toxins. Common contaminants include organic mercury compounds, especially methylmercury, which are known to bioaccumulate and biomagnify in the food chain. Black storks (Ciconia nigra) predominantly consume fish and are thus at risk for high mercury intake. In this study, we used eggshells of black storks as a proxy to reconstruct the concentration levels and distribution of mercury, a well-known toxic element, in various parts of Latvia. Preliminary analyses have shown that deposition levels of mercury vary in different parts of the eggshell. Specifically, the shell and shell membrane differ in their level of mercury contamination by an average factor of nine; therefore, we measured the mercury content in these components separately whenever possible. We analysed 34 eggshell samples from nesting sites in Latvia using an atomic absorption spectrometer with Zeeman correction Lumex RA-915M and its attachment for pyrolytic combustion. We found that mercury concentrations varied from 5 to 22 ng/g in eggshells and from 42 to 293 ng/g in shell membranes. We discuss possible contamination sources and reasons behind this disparity.

Presence of one ecto- and two endoparasite species of the black stork (Ciconia nigra) in Portugal

BackgroundThe black stork (Ciconia nigra Linnaeus, 1758) is a recognized endangered species in Europe and most of the specimens from the Western Palearctic region breed in the Iberian Peninsula. Available works regarding parasites in black storks are scarce. This work reports the presence one ecto- and two endoparasite species from a black stork in Portugal.Case presentationA black stork was found in southern Portugal after colliding against electric cables. The specimen did not survive its sustained injuries and a post-mortem exam was performed. During the procedure, several ecto- and endoparasite specimens were found. The collected parasites were lice (Neophilopterus tricolor), nematodes (Desportesius sagittatus) and trematodes (Cathaemasia hians).ConclusionsThree different species of parasites are reported from a black stork in Portugal. Ecto- and endoparasites of C. nigra have not frequently been described in the literature, and this case report is a contribution to the field. Additional studies will be important to better understand the impact that parasites can have on C. nigra health and survival.

Traditional Fish Pond Management Provides Reliable Foraging Opportunities for Migrating Black Storks in Romania

Migrant water birds such as Black Storks Ciconia nigra have progressively started capitalizing on man-managed ecosystems during migration. Behavioural and ecological studies at stopovers are thus key to deliver comprehensive conservation policies. To be able to improve stopover potential for one of the main Black Stork fall passage sites in central Romania, the Dumbraviţa fishing complex, we analysed the species' foraging behaviour in relation to management of water levels and human activities. Afternoon feeding sessions were recorded weekly during two consecutive autumn migration periods in August–September 2017 and 2018. We used focal and scan sampling methods to quantify behavioural patterns based on 168, 10-minute feeding bouts between 16:00 and 18:00. The selection of foraging areas was contingent upon drainage practices and biased towards vegetated sectors of ponds. The time at which the storks started foraging was strongly correlated with the cessation of the daily fish harvest. Hunting strategies involved grabbing (visual) and water probing (tactolocation), the first prevailing in terms of frequency and time allotment and the latter mainly being used in shallow, muddy areas. Until now, traditional fish farming has unintentionally catered to Black Stork feeding preferences. We put forward several long-term management suggestions to secure the stopover potential for Black Storks at Dumbraviţa.

Nest-site selection by the white-tailed eagle and black stork \u2013 implications for conservation practice

BackgroundNesting trees and habitat represent the key factor underpinning stand selection by forest-dwelling birds. While two large European species – the black stork (Ciconia nigra L.) and white-tailed eagle (Haliaaetus albicilla L.) – are known to require old, large trees for nesting, we sought to investigate further by comparing species requirements at the levels of the nesting tree, nesting stand, and landscape. This entailed a detailed examination of forest features within circles of radius 15 m surrounding 16 and 19 trees holding the nests of storks and eagles respectively. The same parameters were also checked in the vicinity of 50 randomly-selected mature trees.ResultsOur results indicate different nesting preferences, with the eagles entirely confining themselves to Scots pine (Pinus sylvestris L.) – a species also chosen by black storks, which nevertheless regularly favour pedunculate oak (Quercus robur L.). Both species select trees of greater girth than the random ones, but white-tailed eagles choose to nest in the vicinity of patches of mature old stands with a loose canopy, to the extent that nesting trees and surrounding trees are of similar ages. In contrast, black storks prefer “veteran” trees with low-set crowns that are much older than any others in their vicinity. Nesting trees of the eagles are away from roads and close to lakes, while black storks do not avoid roads.ConclusionsAs the ages of nesting trees of both species are greater than ages at final cutting in this region’s managed forest, silvicultural measures will need to be adjusted, with small patches of forest spared, or larger areas as “islands” of old-growth. Likewise, as tending and thinning are engaged in, certain trees with horizontal branches will need to remain, with relict trees also left untouched. As it happens, all of these recommendations are anyway key elements of close-to nature silviculture and multifunctional forestry.

Modelling risks posed by wind turbines and power lines to soaring birds: the black stork (Ciconia nigra) in Italy as a case study

Recent growth of investments in wind energy and power industries has increased concerns about the associated adverse impacts on wildlife. In particular, flying vertebrates are especially at risk, both directly, through an extra mortality rate due to collision with turbines and electrocution, and indirectly through habitat loss or fragmentation. In this study, we propose a modelling approach that combines species distribution models and data managed in geographic information systems to predict and quantify the effects of wind turbines and power lines on the breeding habitat of a soaring migratory bird, the black stork Ciconia nigra, in Italy. The species is recolonizing the country, where it had been driven to extinction in the Middle Age by human persecution. Today, infrastructures such as those considered in our study might in fact hamper this recolonization. Our results show a high probability of presence of the species in several areas in Italy. The most important variables in influencing habitat suitability for C. nigra are the mean temperature of May followed by the distance from urban areas, inland wetlands and hydrographic network. Exposure to wind turbine collision and electrocution resulted to be potentially high. In particular, in Northern Italy the main potential risk of mortality for C. nigra is posed by power lines, whereas in southern regions the species might be mostly threatened by wind turbines. Our approach makes it possible to detect suitable areas that, although not yet colonized by the species, would imply a high mortality risk should the species colonize them in the future. The tool we provide may therefore prove useful to conservationists and landscape planners in order to mitigate the impact of human infrastructures on this species and encourage a more sustainable planning.

May sympatric Lesser Spotted Eagles and Black Storks compete for nesting sites in spatially varying environments?

Sympatric species are likely to compete with one another unless there is a low degree of overlap in their resource use, in which case these species are able to coexist. Disclosing of biotic interactions between sympatric species is important from both theoretical and practical perspectives, especially when the species are of conservation concern. However, environmental heterogeneity may introduce variation in the intensity of biotic interactions due to differential a varying species responses to the environmental gradient. In this study, we analysed the overlap in nesting sites between the internationally protected, mature, forest-dwelling Lesser Spotted Eagle Clanga pomarina and the Black Stork Ciconia nigra. The importance of landscape heterogeneity for habitat segregation between these species was also assessed. The nesting sites of 123 pairs of Lesser Spotted Eagles and 78 pairs of Black Storks, located across different landscapes of the Central, Central-Eastern and Eastern Lithuanian ecoregions were described. A series of discriminant analyses were performed to explore the pattern of habitat differentiation between species nesting in the above-mentioned regions. The habitat differentiation was estimated by niche overlap values (range 0-1, with a value 0.6 suggested to be the threshold between coexistence and competition). Comparison of nesting sites of mature forest-dwellers resulted in the niche overlap values for Central, Central-Eastern and Eastern regions being 0.5, 0.63 and 0.55, respectively. These results indicated relatively high niche overdispersion between nesting sites occupied by eagles and storks. Different variables and/or their combinations resulted in habitat differences in each ecoregion. Our data indicate that biotic interaction between species is mediated by environmental heterogeneity. Although our data tend to support the coexistence of the Black Stork and the Lesser Spotted Eagle, in certain regions these mature, forest-dwelling predators may use similar habitats and compete for prime sites under specific landscape structures. We, therefore, propose the necessity of the importance of a spatially-segregated estimation on biotic interactions when developing conservation programmes and allocating conservation actions within the target region.

Complete mitochondrial genome of Ciconia nigra (Ciconiiformes: Ciconiidae), a threatened stork in China

The complete mitochondrial genome (mitogenome) of black stork Ciconia nigra from North China was sequenced by shotgun genome-skimming method. The mitogenome of C. nigra was 17,787 bp in length and consists of 13 protein-coding genes, 22 tRNAs, two rRNAs, and one non-coding control region (D-loop). All protein-coding genes initiate with ATG codon except for ND2, ND3, and COX1, which uses ATA, ATC, and GTG as their initiation codons, respectively. The termination codon of protein-coding genes shows rich diversity with six termination codons (TAA, AGG, AGA, TAG, T, and A). The phylogenetic trees based on 13 protein-coding genes showed that Ciconia formed a monophyletic group, which was sister to the clade clustered by Threskiorothidae species.

Brood sex ratio and nestling physiological condition as indicators of the influence of weather conditions on breeding black storks Ciconia nigra

Abstract In species with sexual dimorphism, raising female or male offspring may be associated with different costs and benefits, resulting in a skewed nestling sex ratio. We examined the influence of: weather conditions, hatching date and brood size on nestling sex ratio in the black stork Ciconia nigra. We used molecular methods to determine the sex of 284 nestlings. Samples were collected during a 12-years study in central Poland. The overall nestling sex ratio was skewed towards females (61%), which are smaller, and presumably easier to raise than males. Delayed hatching date significantly increased the proportion of female nestlings. Warmer temperatures in the pre-breeding season were correlated with lower proportions of males. This is probably mediated by the influence of weather on water levels in black stork foraging sites. The second most important weather trait was total rainfall in May, the month in which the majority of nestlings hatch. Total May rainfall was negatively correlated with the percentage of male offspring. We used blood haemoglobin concentration as an indicator of body condition in a subsample of 122 nestlings. The males from the study population had lower blood haemoglobin concentrations, indicating their poorer body condition and supporting the hypothesis that they are the more vulnerable sex. We also observed that blood haemoglobin concentration of nestlings is lower in late broods. Deteriorating body condition of late offspring can explain the observed increase in female nestling proportions in delayed broods.

Методичні підходи до визначення розміру охоронної ділянки навколо гнізда лелеки чорного Ciconia Nigra (L.)

Наприкінці 2016 р. у законодавче поле України введено поняття охоронної ділянки навколо гнізд рідкісних видів птахів, зокрема занесеного до Червоної книги України (2009) лелеки чорного Ciconia nigra (L.). Радіус ділянки для усіх видів визначено за європейськими стандартами, однак для лелеки він збільшений удвічі, до радіуса 1000 м навколо гнізда впродовж усього року. У 2006-2018 рр. проведено дослідження чисельності, поширення, біотопних преференцій та гніздової біології виду на території Українського Полісся (Волинська, Рівненська, Житомирська, Київська, Чернігівська та Сумська області) та подальший моніторинг гніздової біології чорного лелеки на Західному Поліссі (Волинська та Рівненська області). Дослідженнями доведено, що радіус 1000 м навколо гнізда є надмірним і недоцільним. Першою хибою такого підходу є відсутність врахування сезонності під час створення охоронної ділянки, другою – надмірний радіус. Обґрунтовано оптимальні розміри охоронної ділянки навколо гнізда лелеки чорного. Доведено, що 54 % гнізд розташовані не далі ніж 200 м від краю лісу. Важливість для виду 500-метрової ділянки лісу навколо гнізда підтверджують і білоруські науковці. За їхніми даними, у 83,3 % випадків на цій території знаходиться присід чорного лелеки, який птахи використовують для оцінювання безпеки підльоту до гнізда. Враховуючи сезонність, рекомендовано створювати охоронні ділянки з двох частин – ділянки суворої охорони (радіусом не менше 100 м довкола гнізда) та ділянки сезонної охорони (радіусом не менше 500 м). Ділянка суворої охорони діє впродовж усього року і в ній заборонено будь-яку діяльність, навіть перебування людей. На ділянці сезонної охорони заборонено будь-яку діяльність з 15 березня по 30 липня. На лісових дорогах і просіках, що проходять через ділянку суворої охорони, рекомендуємо встановлювати попереджувальні аншлаги. Роботи здійснено в рамках проекту "Ciconia-Ukraina", який реалізується Західноукраїнським орнітологічним товариством та Державним природознавчим музеєм НАН України, за фінансової підтримки Фонду "Ciconia" (Ліхтенштейн).

Breeding population of Black Stork, Ciconia nigra, in Italy between 1994 and 2016

The Black Stork Ciconia nigra, following an expansion on European scale, started breeding in Italy in 1994 with one pair in the Piedmont Region and one in the Calabria Region. Since then, the breeding pairs established in Italy have progressively increased up to 18 in 2016, and they are currently in Piedmont, Lazio, Campania, Molise, Apulia, Basilicata and Calabria. However, the number of breeding pairs could be higher than 20, as indicated by records and observations of adults and juveniles, during the breeding period in potentially suitable nesting areas. Despite the low population density in Italy, the trend in the breeding population in Northwest and in Southern Central regions seems to show a slight and high increase respectively. Productivity, breeding success and fledging rate have been considered and analysed. A difference between the two macro areas has been found in the choice of nesting sites, which is on trees for Northwest couples, and cliffs for Southern Central couples. It is necessary to further explore the reason why the small Northwest population does not show any increase and range expansion compared to the Southern Central one.

Autumn Passage of Soaring Birds over Dobrogea (Romania): A Migration Corridor in Southeast Europe

The Dobrogea region in southeastern Romania, which is part of the Eurasian-East African Flyway, is listed as one of the important migration corridors for soaring birds on the western coast of the Black Sea. However, our knowledge regarding migration intensity, phenology and geographical patterns of soaring birds over the area is poor. To determine the migration intensity and phenology of soaring birds, we recorded the autumn migration in the Măcin Mountains (northern Dobrogea) from mid-August to the end of October between 2002–2007. To describe the geographical patterns of migration at a regional scale, we recorded migration intensity in the second half of September in 2010 and 2011, simultaneously from 15 and 13 counting points, respectively, covering the entire region of Dobrogea. In the Măcin Mountains we recorded a mean number (±SD) of 11,297 ± 2333.5 (CV = 20.7%) migrating raptors per year, and of 21,367 ± 10,949.3 (51.2%) and 455.6 ± 43.6 (9.6%) migrating White Storks Ciconia ciconia and Black Storks Ciconia nigra, respectively. Migration phenology parameters varied across raptor and non-raptor species. Migration occurred over a broad front, covering all of Dobrogea. However, migration intensity was more pronounced in the western, central and eastern parts of the region, and was less intensive in the northern central areas. Overall, we recorded 30 migrating raptor species and three non-raptor species. The most abundant raptors were Common Buzzard Buteo buteo, European Honey Buzzard Pernis apivorus, Lesser Spotted Eagle Clanga pomarina, Eurasian Sparrowhawk Accipiter nisus and Western Marsh Harrier Circus aeruginosus. The three non-raptor species were White Stork, Black Stork and Great White Pelican Pelecanus onocrotalus. Our study provides the first general overview of the autumn passage of soaring birds over Dobrogea, highlighting the importance of this area as part of a global migration network.

The Black stork Ciconia nigra (Linnaeus, 1758) on the territory of the Volyn administrative region: history of researches and its results

History of researches of the Black Stork Ciconia nigra (L.) is analysed on the territory of Volyn region. There were generalized materials for taking of inventory of stork nests that was conducted by an author in 2006-2007. There are 110-130 breeding pairs by estimation. Carry out analysis of distributing of his nests according to kinds of threes, number of nestling in nests and duration of the long-term use of nests by storks. There were generalized data about phenology of migrations of this species for 1957-2016.

Detection of forest loss on Black Stork (Ciconia nigra L.) breeding sites in the Rivne region (Polissia) by a GIS analysis

The study aims to assess the scale of forest loss (mostly caused by logging) on breeding sites of the local Black Stork breeding population in the Rivne region of Ukraine, within the Polissia nature zone. The study is based on a GIS analysis of the Global Forest Watch data in intersection of circular buffers of different sizes around 141 Black Stork nests. Forest logging was detected on 38,3% of breeding sites in the region, in 100 m buffers around nests. On more than 14% of breeding territories (in 100 m buffers) forest loss exceeded 20% of the total forest area. Therefore, logging is one of the major threats for the local Black Stork population. The method used for the forest loss detection by a GIS analysis seems to be effective for the search of territories with the violation of protection regime for rare birds when resources are limited.

Nesting habitats of Black Stork (Ciconia nigra L.) in Ukrainian forest zone (Polissia) revealed by an overlay analysis in GIS

The study was based on an overlay analysis in GIS. Exact locations of 108 nest and layers representing forest types, prevailing tree species, forest age and productivity (bonitet class) were used. The analysis was performed on the level of individual nests (spatial join to point layer), and on the level of buffers with 500m radius around nests. To find the most preferable forest types for Black Stork we compared the frequency of distribution of forest types on the nesting territories with the frequency of distribution of those types in the study area and in 500m buffers around 108 random points. According to the results of our research, the spatial distribution of Black Stork nests to a great extant follows the general structure of forests in the region. We found some selectivity in case of wet forest types with prevalence of oak with pine, as well as with black alder, but the result is not statistically significant. The only statistically significant relation was found in case of forest age. Black Storks prefer old and mature forests. The most important trees for nesting were oak (53,3%) and pine (29,9%).