Grus Grus Research Articles

Sexual size dimorphism in the Common Crane, a monogamous, plumage-monomorphic bird

Male-biased sexual size dimorphism (SSD) is common and related to male mating success in polygynous birds, but also occurs in monogamous species, in which sexual selection can be strong. In these species, SSD in morphological traits not directly related to reproductive function, such as locomotory or feeding structures, has remained difficult to explain. We present the first biometric data of an archetypal monogamous bird, the Common Crane (Grus grus), based on molecular sexing techniques. Males were heavier and larger than females, with weight showing the largest SSD, followed by wing, central toe, and head length in adults and juveniles. These sexual differences were also present in nine crane pairs where both adults were measured, with values being positively correlated between pair members, suggesting assortative mating and female choice as the main mechanisms driving the evolution of SSD.

Using by‐catch data from wildlife surveys to quantify climatic parameters and timing of phenology for plants and animals using camera traps

AbstractGaining a better understanding of global environmental change is an important challenge for conserving biodiversity. Shifts in phenology are an important consequence of environmental change. Measuring phenology of different taxa simultaneously at the same spatial and temporal scale is necessary to study the effects of changes in phenology on ecosystems. Camera traps that take both time‐lapse as well as motion‐triggered images are increasingly used to study wildlife populations. The by‐catch data of these networks of camera traps provide a potential alternative for measuring several climatic and phenological variables. Here, we tested this ability of camera traps, and quantified climatic variables as well as the timing of changes in plant and animal phenology. We obtained data from 193 camera‐unit deployments during a year of camera trapping on a peninsula in northern Sweden aimed at studying wildlife. We estimated daily temperature at noon and snow cover using recordings provided by cameras. Estimates of snow cover were accurate, but temperature estimates were higher compared with a local weather station. Furthermore, we were able to identify the timing of leaf emergence and senescence for birches (Betula sp.) and the presence of bilberry berries (Vaccinium myrtillus), as important food sources for herbivores. These were linked to the timing of the growth of antlers and the presence of new‐born young for three ungulate species as well as the presence of migratory Eurasian cranes (Grus grus). We also identified the timing of spring and autumn moulting of mountain hares (Lepus timidus) in relation to snow cover. In this novel study, we show the potential of (by‐catch) data from camera traps to study phenology across a broad range of taxa, suggesting that a global network of camera traps has great potential to simultaneously track wildlife populations and the phenology of interactions between animals and plants.

Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus grus grus

For more than half a century, the Western Eurasian Crane (Grus grus grus) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F-statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F-statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F-statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.

Relating national levels of crop damage to the abundance of large grazing birds: Implications for management

Abstract Populations of large grazing birds have increased in Europe during the past five decades, raising conflicts between conservation and farming interests. Managing these conflicts requires knowledge about the currently unknown relationship between population sizes and crop damage levels. We analysed unique data on reported, inspected and compensated crop damage caused by geese, swans and cranes together with data from population surveys in Sweden to investigate how bird abundance is related to damage levels at the national scale between 2000 and 2015. Over the study period, the annual number of damage reports, yield loss and costs for compensation increased. These crop damage levels were positively related to national population indices of common crane, barnacle and greylag goose. The shape of these relationships varied between species and encompassed considerable uncertainty. However, on a year‐to‐year basis (detrended data) we found no evident association between damage levels and bird numbers. Yield loss and compensation costs per reported damage did not increase with higher population indices of greylag goose, but they did so for barnacle goose. Synthesis and applications. We present a novel study of the relationships between different crop damage level indicators (damage reports, yield loss and compensation costs) and population numbers of large grazing birds. We identified a positive relationship with high uncertainty for all cases. We also identified the need to (a) better synchronize the monitoring of damages and bird numbers in time and space and (b) further study the relationships between damage levels and bird numbers at smaller (local and regional) and larger (flyway) spatial scales to reduce the uncertainty of the relationship and to gain a more holistic understanding of the system.

Preliminary results on bird collision with overhead power lines in Hungary: a case study around Pusztaszer Landscape Protection Area

Abstract The literature on bird collision with power lines in Hungary is rather limited. We collected published records and carried out research on birds that collided with overhead wires, and we made a list of species, and the number of individuals recorded, around Pusztaszer Landscape Protection Area. The quality of data did not allow us to do robust statistical tests, and a large amount of collected data was not used in this paper, because of uncertainty. Finally, we used the records of 519 individuals of 63 species that got injured or died during collision with overhead wires. We found evidence, that low-, middle- and high-voltage power lines were all responsible for the collision accidents of birds. Birds that use wetlands or both wetlands and farmlands are the most threatened to collide with overhead electric wires. Most victims of collision accidents belong to Gruiformes, Charadriiformes, Pelecaniformes and Anseriformes orders. Our preliminary results suggest that the bigger the rate of weight and wingspan (wing-loading proxy) is, the greater the risk of birds colliding with power lines, probably because of poor manoeuvrability. Birds that move regularly, on a daily basis between their nests/roost sites and foraging areas are at higher risk to collide with electric wires. Our preliminary results do not support the hypothesis that birds which sit on power lines collide more frequently than birds that do not use wires. It seems that foggy weather circumstances increase the probability of collision events particularly in case of Common Cranes. Some large birds were found with burnt feathers after collision with middle-voltage power lines. A sizeable part of collided birds were protected or strictly protected. Bird collision with overhead wires is a serious problem in Hungary. Collision can be stopped on most dangerous part of overhead wires by converting to underground cabling. It is possible to reduce the number of collision events in case of high-voltage power lines by increasing their visibility. We always recommend underground cabling in case of wetlands, if new segments of electric wires would be carried out.

Conservation success or increased crop damage risk? The Natura 2000 network for a thriving migratory and protected bird

Protected areas are important to support biodiversity and endangered species. However, they are often too small to fulfill the resource requirements of many large and mobile wildlife species, especially when congregating in large numbers. In such cases, wildlife may overflow onto surrounding human-dominated land and cause impacts. The aim of the EU Natura 2000 network is to increase supranational connectivity between protected areas for migratory and protected species such as the common crane (Grus grus). The crane population along the Western European flyway has been increasing rapidly in recent decades, with peaks of 200,000 cranes at specific Natura 2000 sites. We studied 32 GPS-tagged cranes over four migration periods, to test the use of the network by cranes and the potential for impacts on adjacent farmland. During the nighttime, the probability that roosting cranes were located on Natura 2000 sites was 97%. During daytime, the probability of foraging cranes being located on arable land was 68%. The probability of foraging cranes occurring on agricultural fields close to Natura 2000 sites decreased with distance. Such foraging patterns may fuel conflicts between conservation and agricultural objectives. To resolve these conflicts we suggest improved cross-boundary collaboration and policy development among involved states, combined with stakeholder participation to implement effective compensation and damage prevention strategies which are focused upon networks of protected areas.

THE ROLE OF SPECIAL PROTECTED AREAS OF THE MURMANSK PART OF THE GREEN BELT OF FENNOSCANDIA IN THE DIVERSITY CONSERVATION OF RARE BIRD SPECIES

The contribution of the existing and planned protected areas of the Murmansk part of the Green Belt of Fennoscandia to the conservation of the populations of bird species listed in the Red Data Books of the Russian Federation and the Murmansk Region is analyzed. The history of studies of the avifauna of each protected area is considered. The areas best studied by ornithologists (Ainovy Islands of Kandalakshsky Strict Nature Reserve (zapovednik), Pasvik Strict Nature Reserve, Kaita Regional Nature Reserve (zakaznik), planned zakazniks - Pazovsky and Vuorjema) and the least studied ones (Laplandsky Les, Kutsa regional zakaznik, planned Ionn-N'yugoajv, Spruce Forests of Alla-Akkajarvi zaka-zniks. and others) have been identified. The avifauna of the study area totals 256 species, including 35 red-listed species. It is demonstrated that the protected areas do preserve a high biodiversity of birds and maintain their populations. The best performance is observed for the Whooper Swan Cygnus cygnus, Smew Mergellus albellus, White-tailed Sea Eagle Haliaeetus albicilla, Kestrel Falco tinnunculus, Common Crane Grus grus, Dipper Cinclus cinclus and Great Gray Shrike Lanius excubitor. However, for some protected areas of regional status, knowledge gaps need to be filled through implementation of special biodiversity monitoring programs, research on the state of habitats of rare bird species, and assessment of their numbers.

Understanding species distribution in dynamic populations: a new approach using spatio‐temporal point process models

Understanding and predicting a species’ distribution across a landscape is of central importance in ecology, biogeography and conservation biology. However, it presents daunting challenges when populations are highly dynamic (i.e. increasing or decreasing their ranges), particularly for small populations where information about ecology and life history traits is lacking. Currently, many modelling approaches fail to distinguish whether a site is unoccupied because the available habitat is unsuitable or because a species expanding its range has not arrived at the site yet. As a result, habitat that is indeed suitable may appear unsuitable. To overcome some of these limitations, we use a statistical modelling approach based on spatio‐temporal log‐Gaussian Cox processes. These model the spatial distribution of the species across available habitat and how this distribution changes over time, relative to covariates. In addition, the model explicitly accounts for spatio‐temporal dynamics that are unaccounted for by covariates through a spatio‐temporal stochastic process. We illustrate the approach by predicting the distribution of a recently established population of Eurasian cranes Grus grus in England, UK, and estimate the effect of a reintroduction in the range expansion of the population. Our models show that wetland extent and perimeter‐to‐area ratio have a positive and negative effect, respectively, in crane colonisation probability. Moreover, we find that cranes are more likely to colonise areas near already occupied wetlands and that the colonisation process is progressing at a low rate. Finally, the reintroduction of cranes in SW England can be considered a human‐assisted long‐distance dispersal event that has increased the dispersal potential of the species along a longitudinal axis in S England. Spatio‐temporal log‐Gaussian Cox process models offer an excellent opportunity for the study of species where information on life history traits is lacking, since these are represented through the spatio‐temporal dynamics reflected in the model.

The Evolution of a Species-Specific Term: Old Indic <em>Krauñcaḥ (Grus grus)</em>

The emergence in a language of a species-specific term is determined by the morphology and ethology of the species. In Old Indic the onomatopoietic term krauñcaḥ originally designated the Eurasian Crane (Grus grus) like the term kraneche did in Middle German, garan in Welsh and trani in Old Norse, whereas PIE *ger- and its derivatives in Baltic and Russian designated the Demoiselle Crane. When the Indo-Aryan speaking tribes entered the Pañjāb area they used the familiar term krauñcaḥ as a reference to denominate new comparable species; but the IA-speaking tribes' knowledge of the ethology of Eurasian Cranes is not easily discernible in Old Indic; however, assuming a common PIE background five different traits can be seen in early Greek sources, and these traits reappeared later in the well-known veneration for Sārus Cranes (Grus antigone) in India. The term krauñcaḥ was in Old Indic connected with the sound of the call and not with any other trait so it came naturally also to designate the Sārus Crane, whose call closely resembles that of the Eurasian Crane; but familiarity with the morphological and ethological differences between them caused krauñcaḥ to revert to its original meaning, the Eurasian Crane and the indigenous Sārus Crane to be called sārasaḥ. The term krauñcaḥ thus displays a development from monosemy to polysemy and then back to monosemy, determined by the knowledge the IA-speaking tribes gradually gathered about the morphology and ethology of Eurasian Cranes and related or comparable species in Pañjāb area.

Grote trap en kraanvogel als historische broedvogel in Nederland

Great bustard Otis tarda and common crane Grus grus as historic breeding bird in The Netherlands For extinct breeding birds it is often difficult to establish when and why they got extinct. This can be done by comparing the pattern of extinction for different bird species. In this article great bustard and common crane are compared. They became extinct as a breeding bird in the same period and both stayed irregular dwellers in the centuries afterwards. For common crane archeozoological findings suggest they were widespread and common in the Netherlands until 1000 AD. Written sources on hunting from the 14th till 19th century show they were present in different parts of the country. But they were not common anymore. Several of these sources involve breeding birds. In western and southern parts of the Netherlands they became extinct as breeding birds from the 14th till the beginning of the 17th century. In eastern and northern parts they could survive longer as breeding birds. Possibly, in the province of Drenthe this was until the beginning of the 18th century. For great bustard archeozoological findings suggest they were scarce or absent until 1000 AD. Written sources on hunting from the 16th century on show they were present in the western part of the country. Some of these sources describe their status as breeding bird. The sources suggest they became extinct as breeding bird around 1600. Changing landscapes are for both species the main driver of their extinction. Their breeding habitats disappeared by reclamation, intensification of land use and a growing human population. One of the underlying factors was the economic upheaval of the Golden Age (1588-1702). The prosperity made big investments for reclamation possible. Both species were hunting bird and were protected by hunting laws. During the Dutch revolt (1568-1648) these laws could not always be enforced. Lack of protection could be an additional factor in their extinction. The presence of great bustard shows a relation to the Medieval Warm Period. The successive Little Ice Age, starting in the 16th century, may have been a factor in their disappearance.

SYNTHESIS OF STRUCTURAL SCHEMES OF LINKAGE MECHANISMS FOR PORTAL Gantry CRANE JIB SYSTEM

The most common crane structural scheme used in the practice includes 4-link guiding mechanism and 4-link balancing mechanism. Some special crane construction as such designed by Kranbau – Eberswalde contains a 6-link balancing mechanism with structural scheme obtained by conjunction of 2 consecutive 4-hinged units. Similar construction is a subject of research, related to synthesis of 6-links mechanism during designing of new crane constructions. Another paperwork presents an approach for development of jib system of existing gantry crane type. Such approach relates to keep both – jib and arm without changes in their mass, shape and loading conditions. Still another paperwork revealing an approach for synthesis of existing gantry crane allowing minor structural changes by addition of small-sized links to the scheme of balance mechanism without changes in the structure of jib, arm and frame. According Assur’s classification the number of links in each mechanism would be theoretically unlimited although it would cause significant difficulties during production of such systems. Practically, not any crane constructions designed with 8-link or 10-link structural scheme exists. At other side, increasing the number of links is a precondition to more accurate dimensional movement of balance unit. Structural schemes for plain linkage mechanisms appropriate for application in a portal crane are being synthesized. At the synthesis the limitations of the links must be no more than ten and they save the configuration of the crane’s mechanism that is mostly used in practice. Potential applications of 4 different structural schemes indicated as Н1У1, Н2У1, Н1У2 and Н2У2, synthesized by a practical example, are being appraised. Results for alteration of the reduced moment to jib from weights of links of jib system depending on the range of jib with and without useful load are obtained.

Southern Migration Route and Wintering Grounds of the Common Crane of Dubna Premigratory Gathering

The transformation of arid ecosystems into agricultural lands around natural and man-made water reservoirs has led to the formation of large gatherings on the migration routes and wintering grounds of common cranes nesting in the center of the European part of Russia. The marking of the cranes of Dubna premigratory gathering with color rings made it possible to find birds during wintering in Israel in the Hula valley. The tracking of the marked cranes made it possible to find key areas on migration routes for the purposes of their conservation, as well as other possible locations of cranes from Dubna premigratory gatherings in Moscow Region and adjacent areas. The last one is especially important due to a reduction in the area of Dubna gathering and a decrease in the protective and fodder quality of this land.

The Demoiselle crane (Anthropoides virgo) population genetic structure in Russia

The Demoiselle crane ( Anthropoides virgo Linneaus, 1758) is a widespread crane species of Eurasia distributed in the steppe and semi-desert zones from southeast Ukraine eastward to Northern China. The Demoiselle crane uses two wintering grounds in Africa and India corresponding to the European and Asian breeding parts of the range subdivided into several spatially separated breeding flocks. The first estimates of the genetic diversity and differentiation have been obtained from five of them: 1) Azov & Black Sea, 2) Caspian, 3) Volga & Ural, 4) South Siberian and 5) Eastern Asian sampled across the total breeding range in Russia using data from 10 microsatellite loci and the 1 003-bp control region of mitochondrial DNA. In total, the Demoiselle crane demonstrates high level of observed ( H O = 0.638 ± 0.032) and expected ( H E = 0.657 ± 0.023) hete-rozygosity and haplotype diversity ( h = 0.960). Genetic dif­ferentiation among populations has shown to be weak for both the microsatellite loci (Wright’s F ST = 0.052 or AMOVA estimate 0.016) and mtDNA ( F ST = 0.040). No evidence of significant population structuring of the Demoiselle crane has been found using the STRUCTURE analysis of multilo­cus microsatellite genotypes and the NETWORK grouping of control region haplotypes. Despite the haplotype diversity was high, the nucleotide diversity of the species was low (0.0033 ± 0.0003). Negative but non-significant Tajima’s and Fu’s tests did not suggest the recent population expansion in the Demoiselle crane evolutionary history which contrasts to other cranes of the Palearctic (the Eurasian crane Grus grus , and the Hooded crane G. monacha ). These data indicate more stable conditions for the Demoiselle crane breeding groups in the steppe zone in Pleistocene as compared to boreal and subarctic breeding grounds of other crane species.

Habitat use, preference, and utilization distribution of two crane species (Genus: Grus) in Huize National Nature Reserve, Yunnan-Guizhou Plateau, China.

Understanding the habitat use and spatial distribution of wildlife can help conservationists determine high-priority areas and enhance conservation efforts. We studied the wintering habitat use, preference, and utilization distribution of two crane species, that is, the black-necked crane (Grus nigricollis, Przevalski, 1876) and common crane (Grus grus, Linnaeus, 1758), in Huize National Natural Reserve, Yunnan–Guizhou Plateau, southwestern China. Line transects indicated that anthropogenic farmland habitat was highly utilized and was positively selected by both crane species (>90% of flocks observed for both species). Black-necked cranes preferred marshland in spring (February and March) but avoided grassland during the entire wintering period, whereas common cranes avoided both marshland and grassland throughout the entire period. The two cranes species had communal nightly roosting sites and separate daily foraging sites. Black-necked cranes were distributed within two km (1.89 ± 0.08 km) of the roosting site, covering an area of 283.84 ha, with the core distribution area encompassing less than 100 ha. In contrast, common cranes were distributed far from the roosting site (4.38 ± 0.11 km), covering an area of 558.73 ha, with the core distribution area encompassing 224.81 ha. Thus, interspecies competition may have influenced the habitat preference and spatial distribution divergence of these two phylogenetically related species. This study should help guide habitat management as well as functional zoning development and adjustment in the future. Based on our results, we recommend restoration of additional wetlands, retention of large areas of farmland, and protection of areas that cranes use most frequently.

The role of immigration and reinforcement in the population dynamics of a long‐lived bird: implications for the conservation of threatened species

AbstractUnderstanding population dynamics requires knowledge of the differential effects of survival, productivity and dispersal on population growth. This is particularly important for the conservation of small and recently established populations, where stochastic births and deaths may result in negative growth and even extinction. Here, we investigated the population dynamics of a small population of Eurasian cranes Grus grus in the UK and the effect of a population reinforcement in population growth. We also estimated the probability that the conservation status of cranes improves in the future. We developed stochastic population models to assess the population dynamics and the effect of adding 90 individuals between 2010 and 2014. The best‐supported models suggest that the crane population is self‐sustaining with an annual adult survival of 0.88, but suffers from low productivity. In addition, much of the population increase has been driven by immigration of birds from continental Europe. We found that population reinforcement resulted in a 50% increase in the projected population size, from 178 to 275 breeding pairs over the next 50 years. We showed that the relative contribution of immigration to population growth declined from 43%, when the translocated birds were not considered, to 29%, when they were included in the breeding pool. Moreover, after the population reinforcement, the probability of the population improving its conservation status increased from just above zero to 32%. In light of the recent increase in translocation programs worldwide, our study highlights the need to consider population dynamics to successfully predict the increase in population size when management strategies, such as reintroductions and reinforcements, are planned.

A simple strategy for improving bird sexing from highly degraded DNA samples

A simple methodology was developed to select new sex-specific primers for bird sexing from degraded and low-quantity DNA sources. The strategy was validated using highly degraded DNA extracted from Giemsa-stained blood smears of common cranes (Grus grus). The new primers allowed the accurate molecular sexing using (i) a classic approach of PCR followed by agarose gel electrophoresis and (ii) an advanced real-time PCR method. The simplicity, speed and low cost make this methodology a versatile molecular tool for selection of novel markers/primers for bird sex differentiation from complex DNA sources, which can be used as basis or complement in several fields of ornithological research.

Study of technologies and processes in shipbuilding industry

Shipbuilding industry is an important and strategic industry. The global shipbuilding industry has been dominated by Asian countries (China, Korea and Japan). Metal Processing technologies used on the steel are (straightening, shotblasting, priming) marking, forming, cutting and welding. As will to recognize the common materials-handling and cranes multi-loads to be used in shipyard. The methodology of determination for the shipyard location factors is presented in the current work. It was determined most of the factors. Some may not be important for some countries or facilities. The selected layouts exhibit forms and arrangements of shipyards. Then, mentioned the layout planning method which will effect on competitiveness and productivity. From the studies and experiences it emerged that the product work breakdown structure "PWBS" and Group Technology improves the production and the Quality of the shipbuilding industry

О дуэтах серых журавлей в период размножения

О дуэтах серых журавлей в период размножения

Drifting space use of common cranes—Is there a mismatch between daytime behaviour and management?

Many populations of large grazing birds (cranes, geese, swans) have recovered following protection. During migration, these birds often aggregate in large numbers at staging sites and feed on agricultural crops. Because staging sites often coincide with protected wetlands, extensive crop damages may avert both bird and wetland conservation. There is a need to integrate damage mitigation and conservation of large grazing birds staging in agricultural landscapes, based on knowledge of large grazing birds’ spacing behavior. Their space use forms the basis for assessment of damage risk and for the scale at which measures should be implemented. We used high-resolution GPS location data to assess space use of common cranes (Grus grus) at an important staging site in south-central Sweden. We focus on daytime behaviour because this is the time when foraging cranes may cause crop damage and when preventive measures such as scaring and culling are conducted. We found that the daily activity area (mean 4.4km2) did not vary within staging periods. Cranes exhibited high site fidelity during staging, as their activity area over the staging period (mean 15.6km2) was considerably smaller than the entire staging site (>200km2). However, on a daily scale cranes gradually shifted activity areas, forming a space use pattern analogous to overlapping rings. This pattern is presumably explained by heterogeneous and unpredictable food availability caused by continuous changes in agricultural practices, weather conditions and competition. Considering the size of crane activity areas over the staging period and the scale of current damage preventive measures (e.g., hunting permissions given for a few fields [mean size 0.049km2] at a time), we suggest that current preventive measures might be implemented on a too small scale compared to that of crane space use. Our findings highlight the necessity of adapting crop damage preventive measures to the scale of bird space use to facilitate both bird conservation and agricultural practices at wetlands staging sites along the flyways.

Evaluation of enteromicroflora of common crane (Grus grus) as a potential reservoir of bacterial antimicrobial resistance

AbstractMigratory birds could be important vectors of pathogenic bacteria and antimicrobial resistance transmissions over long distances. The common crane (