Yordan S. Koshev

Yordan S. Koshev
Bulgarian Academy of Sciences | BAS · Institute of Biodiversity and Ecosystem Research

PhD

About

165
Publications
10,606
Reads
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302
Citations
Introduction
Yordan S. Koshev currently works at the Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences. Yordan does research in Genetics, Evolutionary Biology and Ecology. Their current project is 'Analysis of the Adaptation of European Squirrel (Spermophilus citellus) after translocation by studying the level of stress and invasion with endoparasites'.

Publications

Publications (165)
Article
The Sciuridae family is generally referred to as herbivorous and occasionally omnivorous. Although sciurids are known to opportunistically feed on carcasses of other vertebrates (including cannibalism), the active predation on vertebrates is presumably rare. Here, we present a case of a European ground squirrel (Spermophilus citellus) catching and...
Article
Full-text available
The current publication gives a detailed assessment of the results from a population reinforcement of a European ground squirrel's ( Spermophilus citellus ) colony in south-eastern Bulgaria. The reinforcement was planned and implemented along with multidisciplinary research of the adaptation process (including radiotelemetry, parasitological study...
Book
Full-text available
Европейският лалугер (Spermophilus citellus) е дневно активен гризач, който живее на колонии в безлесни местообитания на Централна и Югоизточна Европа. Неговият ареал намалява съществено в Европа, включително и в България. Обитава открити необработваеми тревни местообитания (ливади, пасища, сухи степи и др.), като според функцията си местообитаният...
Article
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We report the changes in the distribution of three alien mammal species in Bulgaria, the coypu Myocastor coypus, the muskrat Ondatra zibethicus, and the raccoon dog Nyctereutes procyonoides after their entry into Bulgaria in the fifties and sixties of the last century. The data has been summarised from field surveys, reviews from scientific literat...
Article
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Here we summarize all available data about dormice (Gliridae) in Bulgaria, published one and our own observations, collected in the last 20 years. Four species are found in Bulgaria - the Forest Dormouse ( Dryomys nitedula ), the Edible Dormouse ( Glis glis ), the Hazel Dormouse ( Muscardinus avellanarius ) and the Roach’s Mouse-tailed Dormouse ( M...
Article
The spatial behaviour of 47 European ground squirrels (Spermophilus citellus) was investigated through radio-collars in the frame of a conservation project for population reinforcement in south-eastern Bulgaria. For the first time both translocated and resident individuals were collared. After the release, each individual’s movement was followed ho...
Article
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Science - popular article discussing the possibility of American minks in Bulgaria becoming infected with COVID - 19. The publication is published at the site nauka.offnews: https://nauka.offnews.bg/news/Biologiia_16/Vazmozhno-li-e-v-Balgariia-da-se-razvie-epidemiia-ot-COVID-19-pri-amer_159563.html
Article
The European ground squirrel (Spermophilus citellus) is a rodent inhabiting the open grasslands of central and southeastern Europe. The species is endangered, and various conservation activities are being conducted to preserve and improve the populations’ status, especially during the recent years including translocations of individuals. The succes...
Article
The Srebarna lake, near the Danube River, Bulgaria, is a key site for biodiversity, specifically for ornithofauna. Thus, it has been designated as a managed nature reserve, a biosphere reserve, a Ramsar site, an Important Bird Area and Natura 2000 sites. Srebarna (and recently Persina Island) hosts the only breeding colonies of the Dalmatian pelica...
Article
Full-text available
The European ground squirrel (Spermophilus citellus) is a vulnerable species, whose populations are declining throughout its entire range in Central and South-Eastern Europe. To a great extent, its conservation depends on habitat restoration, maintenance and protection. In order to improve the conservation status of the species, reintroductions are...
Article
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In 2013, the American mink farming was resumed in Bulgaria and currently, there are four livestock farms with a total capacity of about 130,000 minks. In the period 01.08.2017 – 11.03.2019, the occurrence and potential damages of escaped minks in the area of the largest farm near the village of Madzherito (Stara Zagora District) (with a capacity of...
Article
Full-text available
The European ground squirrel ( Spermophiluscitellus ) is a vulnerable species (IUCN) living in open habitats of Central and South-eastern Europe. Translocations (introductions, reintroductions and reinforcements) are commonly used as part of the European ground squirrel (EGS) conservation. There are numerous publications for such activities carried...
Article
Full-text available
Научно-популярна статия свързана с природозащитният статус на европейския лалугер (Sermophlius citellus) и нуждата от неговата промяна в по-висок - застрашен? A scientifically popular article on the conservation status of the European ground squirrel (Sermophlius citellus) and the need to change it to a higher - endangered?
Conference Paper
Full-text available
Introduction In search of more data about the EGS individuals' fate after conservation translocations we equipped 18 animals with radio-collars during new reinforcement project in "Zapadna Strandzha" SPA, Bulgaria. Methods The animal's location was recorded daily for 13 days (July-September) and the distance to the mean release point was calculated...
Conference Paper
Full-text available
Introduction Repatriations of European ground squirrel (EGS) are commonly used for its conservation in Central Europe, but until now there is no data about such activities in Southeastern Europe. Methods The current study presents an overview of authors’ personal data and publicly available data (published articles, unpublished records etc.) fo...
Poster
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The SDMs (species distribution models) or ENMs (ecological niche models) now are widely used methods for prediction of distribution of threatened mammals. The aim of the study was to generate a habitat suitability model for S. citellus in Bulgaria. To investigate current distribution and potentially needed conservation actions, a GIS based analysis...
Article
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The European Souslik is an important component of the diet of protected bird and mammal species. This is a threatened species whose population and distribution area have been shrinking in its entire range. Translocation is often used to restore the species' distribution and abundance. Unlike Central Europe, there is only scarce experience in the im...
Article
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A review on the composition of the small mammals in Vrachanska Planina Mts. was completed using published and author's data. A total of 27 species occur within the territory. All of the species found are typical for the region. The species with the highest conservation status, the European ground squirrel Spermophilus citellus, disappeared from the...
Poster
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Here we provide information about the current status of two hamster species, C. cricetus and M. newtoni, in Bulgaria.
Article
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Ponor Special Protection Area (Ponor SPA) is part of the Western Stara Planina (Western Balkan Range) and includes open grasslands and forests. Twenty-seven species of small mammals were detected in it: 1 species of the order Erinaceomorpha, 7 species of the order Soricomorpha, 1 species of the order Lagomorpha and 18 species of the order Rodentia....
Article
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During field surveys for small mammals in Bulgaria we found specimens of Crocidura leucodon, Talpa europaea and a Mus sp with color variation. We reviewed the national scientific collections and the available literature for cases of small mammals with color variations. Color variation in small mammals is very rare, so far we found nine cases onl...
Article
This work presents novel data that has allowed us to propose an evolutionary model for the karyotype of the European ground squirrel (Spermophilus citellus, L. 1766) based on sex chromosome variants. Routine C- and G- banding, specific fluorochrome staining (CMA3, DAPI) and FISH experiments were used to characterize the pattern of chromosomal varia...
Article
Full-text available
Interspecific behaviour of European ground squirrel (Spermophilus citellus) is still poorly studied. During behavioural studies of free-ranging European ground squirrels tree kinds of aggression to other vertebrate species: reptile, bird and mammal (Lacerta trilineata, Corvus frugilegus, Mustela nivalis) have been described. To our knowledge, this...
Article
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Twenty-five species of small mammals were registered in the Besaparski Ridove Special Protection Area: Erinaceomorpha (1 species), Soricomorpha (5 species), Lagomorpha (1 species) and Rodentia (17 species). Species composition and distribution were studied by observing the traces left after the life activity as well as by using pitfall traps, live...
Technical Report
Full-text available
Методика за мониторинг на обикновения хомяк (Cricetus cricetus в България е разработена по проект "I фаза - Договор № 2597/22.07.2013 г. "Теренни проучвания на разпространение и численост на бозайници (без китоподобни)" http://eea.government.bg/bg/bio/opos/activities-results/Cricetuscricetus_MetodikazaMonitoring.pdf
Technical Report
Full-text available
Методика за мониторинг на Добруджански хомяк (Mesocricetus newtoni) е разработена в рамките на преокт "I фаза" Договор № 2597/22.07.2013 г. "Теренни проучвания на разпространение и численост на бозайници (без китоподобни)" http://eea.government.bg/bg/bio/opos/activities-results/Mesocricetusnewtoni_MetodikazaMonitoring.pdf
Technical Report
Full-text available
Методика за оценка състоянието на Обикновен хомяк (Cricetus cricetus Linnaeus, 1758) е изработена по проект I фаза" Договор № 2597/22.07.2013 г. "Теренни проучвания на разпространение и численост на бозайници (без китоподобни)"
Technical Report
Full-text available
Методиката за оценка на състоянието на добруджанския хомяк е изготвена по проект Проект "Теренни проучвания на разпространение на видове / оценка на състоянието на видове и хабитати на територията на цялата страна – I фаза" Договор № 2597/22.07.2013 г. „Теренни проучвания на разпространение и численост на бозайници (без китоподобни)“
Article
The theory of classical and cryptic Pleistocene refugia is based mainly on historical changes in temperature, and the refugia are usually defined within a latitudinal gradient. However, the gradient of oceanic-continental climate (i.e. longitudinal) was also significantly variable during glacial cycles with important biotic consequences. Range-wide...
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