Grzegorz Maciorowski

Poznań University of Life Sciences · Department of Game Management and Forest Protection

Abstract: Using global position system (GPS) technology, we tracked an adult female greater spotted eagle (Clanga clanga) on its wintering grounds in the Sudan-South Sudan borderland during 2005-2015. There were 10 909 GPS locations for this bird in the non-breeding range. Throughout the study, the eagle showed fidelity to its wintering grounds. Th...

Using global position system (GPS) technology, we tracked an adult female greater spotted eagle ( Clanga clanga ) on its wintering grounds in the Sudan-South Sudan borderland during 2005–2015. There were 10 909 GPS locations for this bird in the non-breeding range. Throughout the study, the eagle showed fidelity to its wintering grounds. The non-br...

Calls for urgent action to conserve biodiversity under global change are increasing, and conservation of migratory species in this context poses special challenges. In the last two decades the Convention on the Conservation of Migratory Species of Wild Animals (CMS) has provided a framework for several subsidiary instruments including action plans...

Characterizing the genetic diversity and structure of populations is essential for understanding their evolutionary history and planning species conservation. The lesser spotted eagle (Clanga pomarina) is a large migratory raptor with a relatively small breeding range concentrated in Eastern Europe. We evaluated the level of genetic diversity and p...

Understanding connectivity between migratory bird breeding and wintering grounds is essential for range-wide planning of conservation activities. We used GPS tracking to explore the migration of 28 ‘Endangered’ Greater Spotted Eagles, Clanga clanga from three remaining European breeding populations towards their wintering range, and to identify pop...

Anthropogenic activity results in production of wastes, including litter in the environment. The problem of waste pollution is especially noticeable and usually discussed from the perspective of marine environments. It is significantly less addressed in terrestrial habitats, where the spatial dispersion of litter makes it difficult to assess the de...

According to previous studies using colour rings, lesser spotted eagles Clanga pomarina have established breeding territories up to 249 km from their natal site. A colour-ringed lesser spotted eagle nestling from NE Poland settled 540 km further west in NE Germany. This male was discovered at the age of six and nested there for several years. This...

Animal home‐ranges are expressions of the biology and ecology of a species and their size is often considered a proxy for habitat quality. Understanding the factors affecting variation in home‐range size may aid prediction of the impact of local or global environmental change on studied populations. To this end, we established an international coll...

Top‐predators, including birds of prey, play an important role in ecosystems and are good bioindicators (Sergio et al. 2005). Links between the presence of predators and the overall biodiversity of a particular habitat mainly focus on trophic relationships (Roth and Weber 2008, Sergio et al. 2008b, Burgas et al. 2014). However, top‐predators not on...

We studied the long-term changes in numbers and habitat structures of two sympatric species—Red Kite Milvus milvus (RK) and Black Kite Milvus migrans (BK)—in two study plots (a mosaic of various habitats and intensive farmland) in western Poland. This research, carried out in two periods (1996–2001 and 2012–2017), did not reveal any significant cha...

Abstract. Post-fledging behaviour and mortality between the place of birth and wintering sites can be crucial to populations of raptors. We studied this phenomenon during the autumn migration of immature Red Kite Milvus milvus using telemetry data on the population breeding in western Poland. In total 34 immatures from 17 nests were ringed and GPS–...

High genetic diversity and low differentiation retained in the European fragmented and declining Greater Spotted Eagle (Clanga clanga) population Ülo Väli, Valery Dobrovski, Marina Dzmitranok, Grzegorz Maciorowski & Bernd-Ulrich Meyburg Characterising genetic diversity and structure of populations is essential for effective conservation of threa...

Characterising genetic diversity and structure of populations is essential for effective conservation of threatened species. The Greater Spotted Eagle (Clanga clanga), a large and globally vulnerable raptor, is extinct or in severe decline in most of its previous range in Europe. We assessed whether the remnants of European population are genetical...

Hybridization, the interbreeding of different species, plays an important role in several evolutionary processes but can have detrimental effects on the species involved, including extinction. We documented increased levels of hybridization between two Clanga species (Lesser-spotted Eagle C. pomarina and Greater Spotted Eagle C. clanga), following...

The relative contributions of genetic and social factors in shaping the living world are a crucial question in ecology. The annual migration of birds to their wintering grounds and back provides significant knowledge in this field of research. Migratory movements are predominantly genetically determined in passerine birds, while in large soaring bi...

The Greater Spotted Eagle is an extremely rare species which is strongly associated with wetlands during the breeding period. The winter habitats of this vulnerable species have not been extensively studied so far, although eagles spend over one third of the year there, and these are therefore also crucial for the conservation of the species. We in...

We studied a sympatric and crossbreeding population of the Lesser and the Greater Spotted Eagle in the Biebrza Valley, NE Poland. In order to follow the dynamics of hybridisation and its possible causes we monitored these two species between 1996 and 2012, using visual and genetic species identification. Individuals in up to 51 territories annually...

Krajowy Progam Ochrony Orlika Grubodziobego. Projekt

Foraging sites of Aquila clanga compared to Aquila pomarina are characterized by a considerably longer duration of flooding within the year and higher mean and maximum depths of flooding. A. clanga is particularly associated with shallow (approx. 20 cm) spring flooding, lasting at least up to the beginning of May (on average up to 90 days per year)...

Wetlands in the Biebrza Valley, north-east Poland, are inhabited by two closely related Aquila species: the more numerous Lesser Spotted Eagle A. pomarina prefers human-transformed landscapes, whereas the very rare Greater Spotted Eagle A. clanga is associated with natural marshy landscapes. At least since the last decade of the 20 th century, thes...

Evidence of breeding rooks feeding on Roman snails (Helix pomatia) and grove snails (Cepaea nemoralis) is presented. Shell dimensions of food remains and intact Roman snails collected in the study area were measured in order to estimate the size and shape of the snails collected by rooks in relation to the food available in the vicinity of the rook...

GPS telemetry in studying spatial ecology of Lesser Spotted Eagle in Biebrza Valley. Spatial ecology of Lesser Spotted Eagle was studied in Biebrza Valley in 2011-2013. Three adult males were captured. Two of them was tagged with GPS GSM loger and one with satellite transmitter. Only first tagged male transmitted for the whole annual cycle. The sec...

Hybridization is a significant threat for endangered species and could potentially even lead to their extinction. This concern applies to the globally vulnerable Greater Spotted Eagle Aquila clanga, a species that co-occurs, and potentially interbreeds, with the more common Lesser Spotted Eagle Aquila pomarina in a vast area of Eastern Europe. We a...

The correct identification of hybrids is essential in avian hybridisation studies, but selection of the appropriate set of genetic markers for this purpose is at times complicated. Microsatellites and single nucleotide polymorphisms (SNPs) are currently the most commonly used markers in this field. We compare the efficiency of these two marker type...

Colour ringing of the Spotted Eagles ( Aquila pomarina, Aquila clanga and their hybrids) in Europe - a review During the years 2000-2008 1377 Spotted Eagles (SE) ( Aquila pomarina , Aquila clanga and their hybrids) have been colour ringed in Europe. Out of these, 1303 (94.6 %) were young birds and 74 (5.4 %) were adults. Out of the total, 1290 (93....

Winter and summer stocks as well as density distributions of the Common Buzzard Buteo buteo in German - Polish lowland are treated in this publication. Both summer and winter stocks were determined by means of the point counts which were adapted to respective seasons. The density per point on the visible area (indiv. / 10km2) was determined in wint...

Mizera, T., G. Maciorowski & B.-U. Meyburg 2001. Aquila clanga (Pallas, 1811) Greater Spotted Eagle. Pp. 145-148 in: Glowacinski, Z. (ed.). Polish Red Data Book of Animals - Vertebrates. Warszawa: Panstwowe Wydawnictwo Rolnicze I Lesne. (Polish, English summ.)

During the years 2000-2008 1377 Spotted Eagles (SE) (Aquila pomarina, Aquila clanga and their hybrids) have been colour ringed in Europe. Out of these, 1303 (94.6 %) were young birds and 74 (5.4 %) were adults. Out of the total, 1290 (93.7 %) were the Aquila pomarina Lesser Spotted Eagles (LSE) - 1229 (95.3 %) young and 61 (4.7 %) adults, 50 (3.6 %...