62 research outputs found

    Year-round tracking of small trans-Saharan migrants using light-level geolocators

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    Since 1899 ringing (or banding) remained the most important source of information about migration routes, stopover sites and wintering grounds for birds that are too small to carry satellite-based tracking systems. Despite the large quantity of migrating birds ringed in their breeding areas in Europe, the number of ring recoveries from sub-Saharan Africa is very low and therefore the whereabouts of most small bird species outside the breeding season remain a mystery. With new miniaturized light-level geolocators it is now possible to look beyond the limits of ring recovery data. Here we show for the first time year round tracks of a near passerine trans-Saharan migrant, the European Hoopoe (Upupa epops epops). Three birds wintered in the Sahel zone of Western Africa where they remained stationary for most of the time. One bird chose a south-easterly route following the Italian peninsula. Birds from the same breeding population used different migration routes and wintering sites, suggesting a low level of migratory connectivity between breeding and wintering areas. Our tracking of a near passerine bird, the European Hoopoe, with light-level geolocators opens a new chapter in the research of Palaearctic-African bird migration as this new tool revolutionizes our ability to discover migration routes, stopover sites and wintering grounds of small birds

    Bringing home the trash: Do colony-based differences in foraging distribution lead to increased plastic ingestion in Laysan albatrosses?

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    When searching for prey, animals should maximize energetic gain, while minimizing energy expenditure by altering their movements relative to prey availability. However, with increasing amounts of marine debris, what once may have been ‘optimal’ foraging strategies for top marine predators, are leading to sub-optimal diets comprised in large part of plastic. Indeed, the highly vagile Laysan albatross (Phoebastria immutabilis) which forages throughout the North Pacific, are well known for their tendency to ingest plastic. Here we examine whether Laysan albatrosses nesting on Kure Atoll and Oahu Island, 2,150 km apart, experience different levels of plastic ingestion. Twenty two geolocators were deployed on breeding adults for up to two years. Regurgitated boluses of undigestable material were also collected from chicks at each site to compare the amount of plastic vs. natural foods. Chicks from Kure Atoll were fed almost ten times the amount of plastic compared to chicks from Oahu despite boluses from both colonies having similar amounts of natural food. Tracking data indicated that adults from either colony did not have core overlapping distributions during the early half of the breeding period and that adults from Kure had a greater overlap with the putative range of the Western Garbage Patch corroborating our observation of higher plastic loads at this colony. At-sea distributions also varied throughout the year suggesting that Laysan albatrosses either adjusted their foraging behavior according to constraints on time away from the nest or to variation in resources. However, in the non-breeding season, distributional overlap was greater indicating that the energy required to reach the foraging grounds was less important than the total energy available. These results demonstrate how a marine predator that is not dispersal limited alters its foraging strategy throughout the reproductive cycle to maximize energetic gain and how this has led to differences in plastic ingestion

    Blockchain Technology in the Field of Energetics: Organization of Effective Energy Market

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    The article is devoted to the topic of blockchain applications in the field of energetics. A role of the technology in the digital economy development has been discussed; corresponding examples from Russian, Chinese, Estonian experience have been presented. A synergy between usage of blockchain and other information technology such as big data, intelligent avatars and the Internet of things has been demonstrated. Implementation of the blockchain technology into the functional scheme of the energy market has been proposed as a ways to ensure its decentralization and openness. Energy supply contracts can be negotiated directly between producers and consumers without intermediaries, so all the market actors have a high level of autonomy in purchasing and selling. The technology provides services for preparation and issuance of necessary invoices, as well as for making settlements for the entire transaction. Blockchain technology ensures economic and information security of transaction participants and includes convenient tools for realization of their market activities. Difficulties and risks, connected with the technology implementation, have been discussed, as well as main ways of its further development

    Influence of sea surface winds on shearwater migration detours

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    To test the potential effects of winds on the migratory detours of shearwaters, transequatorial migrations of 3 shearwaters, the Manx Puffin us puffinus, the Cory's Calonectris diomedea, and the Cape Verde C. edwardsii shearwaters were tracked using geolocators. Concurrent data on the direction and strength of winds were obtained from the NASA SeaWinds scatterometer to calculate daily impedance models reflecting the resistance of sea surface winds to the shearwater movements. From these models we estimated relative wind-mediated costs for the observed synthesis pathway obtained from tracked birds, for the shortest distance pathway and for other simulated alternative pathways for every day of the migration period. We also estimated daily trajectories of the minimum cost pathway and compared distance and relative costs of all pathways. Shearwaters followed 26 to 52% longer pathways than the shortest distance path. In general, estimated wind-mediated costs of both observed synthesis and simulated alternative pathways were strongly dependent on the date of departure. Costs of observed synthesis pathways were about 15% greater than the synthesis pathway with the minimum cost, but, in the Cory's and the Cape Verde shearwaters, these pathways were on average 15 to 20% shorter in distance, suggesting the extra costs of the observed pathways are compensated by saving about 2 travelling days. In Manx shearwaters, however, the distance of the observed synthesis pathway was 25% longer than that of the lowest cost synthesis pathway, probably because birds avoided shorter but potentially more turbulent pathways. Our results suggest that winds are a major determinant of the migratory routes of seabirds

    Direct radiative effect of aerosols emitted by transport from road, shipping and aviation

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    Aerosols and their precursors are emitted abundantly by transport activities. Transportation constitutes one of the fastest growing activities and its growth is predicted to increase significantly in the future. Previous studies have estimated the aerosol direct radiative forcing from one transport sub-sector, but only one study to our knowledge estimated the range of radiative forcing from the main aerosol components (sulphate, black carbon (BC) and organic carbon) for the whole transportation sector. In this study, we compare results from two different chemical transport models and three radiation codes under different hypothesis of mixing: internal and external mixing using emission inventories for the year 2000. The main results from this study consist of a positive direct radiative forcing for aerosols emitted by road traffic of +20±11 mW m−2 for an externally mixed aerosol, and of +32±13 mW m−2 when BC is internally mixed. These direct radiative forcings are much higher than the previously published estimate of +3±11 mW m−2. For transport activities from shipping, the net direct aerosol radiative forcing is negative. This forcing is dominated by the contribution of the sulphate. For both an external and an internal mixture, the radiative forcing from shipping is estimated at −26±4 mW m−2. These estimates are in very good agreement with the range of a previously published one (from −46 to −13 mW m−2) but with a much narrower range. By contrast, the direct aerosol forcing from aviation is estimated to be small, and in the range −0.9 to +0.3 mW m−2

    Increasing accuracy: a new design and algorithm for automatically measuring weights, travel direction and radio frequency identification (RFID) of penguins.

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    A fully automated weighbridge using a new algorithm and mechanics integrated with a Radio Frequency Identification System is described. It is currently in use collecting data on Macaroni penguins (Eudyptes chrysolophus) at Bird Island, South Georgia. The technology allows researchers to collect very large, highly accurate datasets of both penguin weight and direction of their travel into or out of a breeding colony, providing important contributory information to help understand penguin breeding success, reproductive output and availability of prey. Reliable discrimination between single and multiple penguin crossings is demonstrated. Passive radio frequency tags implanted into penguins allow researchers to match weight and trip direction to individual birds. Low unit and operation costs, low maintenance needs, simple operator requirements and accurate time stamping of every record are all important features of this type of weighbridge, as is its proven ability to operate 24 hours a day throughout a breeding season, regardless of temperature or weather conditions. Users are able to define required levels of accuracy by adjusting filters and raw data are automatically recorded and stored allowing for a range of processing options. This paper presents the underlying principles, design specification and system description, provides evidence of the weighbridge’s accurate performance and demonstrates how its design is a significant improvement on existing system

    Summer distribution and migration of nonbreeding albatrosses: individual consistencies and implications for conservation.

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    Abstract. Many birds show a surprising degree of intraspecific variability in migratory tendency and choice of wintering site. In this study, we tracked the seasonal movements of 35 nonbreeding Black-browed Albatrosses Thalassarche melanophrys from South Georgia, including 24 birds followed in two consecutive years. This revealed consistent patterns of status-related, sex-specific, and individual variation in wintering strategies, and provided the first description of the summer distribution of failed/deferring breeders. Individuals exhibited a striking degree of site fidelity, returning to the same region (southwest Africa or Australia) and showing correlated centers of distribution, as well as remarkable consistency in the chronology of their movements, in consecutive years. Nonetheless, a degree of behavioral flexibility remained, and particularly on the return migration, birds moved between, or bypassed, alternative intermediate staging sites depending on local circumstances. Initiation of the outward migration varied according to breeding status, timing of failure, and sex: deferring breeders and those that failed early departed two months before successful birds, and successful females departed 1-2 weeks earlier than males. Sex-related latitudinal variation in distribution was also apparent, with females wintering farther north within the Benguela system. Moreover, the only migrant to Australia was a male, supporting an apparent tendency for male-biased breeding dispersal inferred from genetic analyses. Distribution and timing of movements appeared in general to relate to avoidance of competition from congeners and conspecifics from other populations. From a conservation perspective, the study indicated that, for the declining Black-browed Albatross population at South Georgia, the primary focus should be toward improving the management (especially reducing bycatch levels) of fisheries in the central and eastern South Atlantic

    МР-томография миокарда с парамагнитным контрастным усилением Mn-етоксиизобутилизонитрилом (Mn-МИБИ) в эксперименте

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    Aim: to evaluate with MRI technique the uptake of paramagnetic complex Mn-methoxyisobutylisonitrile (MIBI) to myocardium in rats in normal control animals and in experimental infarction. Material and methods. Complex Mn-MOBI was obtained with one-stage synthesis from manganese (II) carbonate and methoxyisobutylisonitrile hydroxide (produced by the Laboratory of technology and control of radiopharmaceuticals of the A.I. Burnazyan Russian state federal medical and biophysics Center), obtaining finally the 0.5 M solution of Mn-MIBI at pH = 6.3. The Mn-MIBI was injected intravenously slowly to sleeping rats (Telazol, i/m), as 0.05 ml of 0,5 M solution per Kg of BW. For this study nine normal control Whistar rats were employed as well as ten animals with previously induced anterior myocardial infarction of the left ventricle (all males). MRI scanning in T1-weighted spin-echo has been carried out with TR = 500 ms and TE = 15 ms, in axial and frontal slices as thin as 2-2.5 mm, to the matrix 256 х 256, with the field of view as large as 200 х 200 mm. The uptake was scored visually as change in intensity of T1-weighted MRI frontal scans of the whole body of the animals, of axial scans of chest and heart; and also quantitatively, with calculating for the T1-weighted MRI the index of enhancement (IE) of intensity per voxel, as : IE = (MeanInt of T1-w.MRI)Mn-MIBI / (MeanInt of T1-w.MRI)initial Results. Visually on whole-body T1-weighted SE frontal scans the MN-MIBI induced increase of intensity of the heart image, essentially equal for all parts of the left ventricle and less intense over the right ventricle. The values of the IE were over 2.5 for all parts of the left ventricle, whereas only 1.8-1.9 in case of the septum. IE of the right ventricle did not differ significantly when compared to the LV values. When injected to animals with experimental myocardial infarction the Mn-MIBI did not induced any essential changes of intensity in non-perfused regiones, with IE = 1.19 ± 0. 08, but raised the intensity over intact lateral wall of the left ventricle, with IE = 2.65 ± 0.14, and also over intact anterior wall, with IE = 2.28 ± 0.17. Conclusion. Complexonate Mn-MIBI provides well enough intense enhancement of myocardium in T1-SE MRI and makes possible to image severe disorders of myocardial blood flow in experimental models. The Mn-MIBI complex can be suggested as basic molecule for nearest future design of paramagnetic contrast agents for myocarrdial perfusion imaging, as well as for other organs taking up the MIBI. Manganese also is conceivable to be employed for labelling of other complexones currently in use in nuclear medicine.Цель исследования: попытка оценки по данным МРТ накопления парамагнитного комплекса Mn-метоксиизобутилизонитрила (МИБИ) в миокарде у крыс в норме и при экспериментальном инфаркте. Материал и методы. Комплекс Mn с МИБИ был получен в один этап из карбоната марганца (II) и гидроксида метоксиизобутилизонитрила (синтезированного лабораторией технологий и методов контроля радиофармпрепаратов ГНЦ России - ФМБЦ им. А.И. Бурназяна) с выходом в итоге 0,5 М раствора Mn-МИБИ при pH 6,3. Препарат Mn-МИБИ вводился внутривенно медленно из расчета 0,05 мл 0,5 М раствора на 1 кг массы тела. В исследование включено 9 контрольных белых крыс и 10 (все самцы) с предварительно смоделированным инфарцированием передней стенки сердца. Сканирование в Т1-взвешенном спин-эхо выполнено до и спустя 8-10 мин после введения Mn-МИБИ при TR 500 мс и TE 15 мс в аксиальных и сагиттальных плоскостях при толщине среза 2-2,5 мм в матрицу 256 х 256 и при размерах поля сканирования 200 х 200 мм. Оценивалались визуальные изменения картины Т1-взвешенной МРТ всего тела и, в частности, сердца, а также количественно степень усиления интенсивности Т1-взвешенного спин-эхо МРТ, как: ИУ = (средн.инт. Т1-взв. МРТ)Mn-МИБИ/ (средн.инт. Т1-взв. МРТ)исходи. Результаты. Визуально отмечалось усиление интенсивности Т1- взвешенного спин-эхо-изображения МРТ в области миокарда левого желудочка в одинаковой степени по всем отделам левого желудочка и визуально меньше - в области правого желудочка. Интенсивность Т1-взвешенных изображений стенок левого желудочка усиливалась в 2,5 раза и более, тогда как в области перегородки - в 1,8-1,9 раза, т.е. достоверно меньше. Индекс усиления правого желудочка не отличался от значений для миокарда левого желудочка. При исследовании у животных с инфарктом миокарда усиление в области инфаркта визуально было незначительным; при количественной оценке индекса усиления для инфарцированных отделов составил 1,19 ± 0,08, в неповрежденной боковой стенке - 2,65 ± 0,14, в неповрежденной передней - 2,28 ± 0,17. Вывод. Комплекс Mn-МИБИ обеспечивает достаточно интенсивное усиление изображение миокарда при МРТ в Т1-взвешенном спин-эхо-режиме и позволяет визуализировать грубые нарушения кровоснабжения сердечной мышцы в эксперименте. Комплекс Mn-МИБИ может рассматриваться как основа для создания парамагнитных контрастных препаратов для визуализации миокарда и, вероятно, также других органов и структур, где было отмечено накопление метоксиизобутилизонитрила. Предполагается использовать комплексонаты99mTc как основу для аналогичных комплексонатов Mn, если их стабильность и R1-релаксивность окажутся достаточными для парамагнитного контрастирования в МР

    A miniature daylight level and activity data recorder for tracking animals over long periods

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    The device has a sensor that periodically measures and records the ambient light level. Following retrieval of the device, the light level records are converted into latitudes and longitudes, which allows the geographic position of the animal to be estimated twice daily. The instrument is also configured to detect and record the history of time spent in water against time spent flying or on land. For seabirds, this can provide time-budget data related to activity and feeding behaviour. Small size, a low profile and robust packaging are crucial for effective deployments on flying birds and diving animals. Long battery life is often essential (e.g. after fledging, juvenile wandering albatrosses Diomedea exulans usually remain at sea for at least five to seven years). Low unit and operation costs are also very desirable, together with simplicity of operation. Dimensions of the instrument are 22◊19◊12 mm. Weight is 9 g in air and 4 g in water. The device is pressure tested to 800 m depth of water, and can log data for up to eight years. The total cost of components is less than $70. The principles, design specification and circuit description of the device are presented here, together with a representative migration track, obtained during field tests on grey-headed albatrosses Thalassarche chrysostoma, to illustrate performance
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