Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 16

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Wykorzystanie rejestratorów audio w monitoringu puchacza na Podlasiu

100%
Mirski P.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2017
|
tom 19
|
nr 4[53]
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Exceptions from dioecy and sex lability in genus Salix

100%
Mirski P.
Dendrobiology
|
2014
|
tom 71
Bisexualism (and its derivatives) is a rare exception in species which already acquired the dioecious breeding system. Although it occurs in some tree species, it is still rather uncommon, except for willows, in which bisexualism occurs in at least 18 species. In most willows such unusual individuals are subdioecious, hermaphroditic or monoecious, or produce intersexes (staminate flowers transform into pistillate flowers or the other way round). The frequency of non-dioecy can vary from a single individual to whole populations, but is in principle rare. Its possible causes are both environmental and genetic. In Salix sex lability is known to be affected by parasites and anthropogenic habitat change. In interspecific willow crosses there are numerous exceptions from dioecy that are mostly caused by polyploidization. Since sex determination in willows is genetic, environmental factors are expected to determine exclusively phenotypic sex traits.
3

Ekologiczne i ewolucyjne uwarunkowania i konsekwencje subdioecji u roślin okrytonasiennych

100%
Mirski P.
Kosmos
|
2011
|
tom 60
|
nr 3-4
4

Selection of nesting and foraging habitat by the Lesser Spotted Eagle Aquila pomarina [Brehm] in the Knyszynska Forest [NE Poland]

100%
Mirski P.
Polish Journal of Ecology
|
2009
|
tom 57
|
nr 3
581-587
To manage conservation issues, it is essential to recognize the factors determining the occurrence of endangered species. This study examined the foraging habitat and nest site preferences of the Lesser Spotted Eagle Aquila pomarina (Brehm) in the Knyszyńska Forest (NE Poland). This is a large (839 km²) protected (Landscape Park Puszcza Knyszyńska, NATURA 2000) forest complex composed mainly with coniferous and mixed wood stands with meadows in river valleys inside the complex and arable lands outside it. The research was carried out on a study plot of 440 km², in the breeding seasons of 2006 and 2007. Nest site characteristics, such as distance to open areas, settlements and watercourses were measured and compared with random points. The habitat composition of hunting territories was recorded and compared to habitat availability on the whole study plot, and the birds’ hunting effort was assessed. The eagles showed a preference for nesting close to open spaces (potential hunting grounds) and watercourses (like rivers and streams), but avoided proximity to human settlements. As hunting grounds, the birds highly preferred grasslands and avoided arable lands. Time spent hunting on grasslands comprised over 95% of the observed hunting activities and grasslands were significantly positively selected both in the whole study plot and within a 2 km-radius from nest. The results suggest that the conservation of the Lesser Spotted Eagle should focus especially on meadows and pastures adjacent to large forest complexes.
5

Liczebność i rozmieszczenie derkacza Crex crex w Białymstoku w 2011 roku

63%
Mirski P., Zbyryt A.
Ornis Polonica
|
2012
|
tom 53
|
nr 3
6

Orliki i antenki, czyli o telemetrii orlików grubodziobych

63%
Maciorowski G., Mirski P.
Ptaki Polski
|
2012
|
nr 2[26]
7
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Wykorzystanie telemetrii GPS w badaniach ekologii przestrzennej orlika krzykliwego w Dolinie Biebrzy

63%
Mirski P., Maciorowski G.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2013
|
tom 15
|
nr 3[36]
8
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Are hermaphrodites better adapted to the colonization process in trioecious populations of Salix myrsinifolia?

63%
Mirski P., Brzosko E.
Acta Societatis Botanicorum Poloniae
|
2015
|
tom 84
|
nr 2
In trioecious plant populations, the role of hermaphroditism is often uncertain. We investigated the advantages of hermaphroditism in the dioecious shrub Salix myrsinifolia. The sex ratio of 30 S. myrsinifolia populations in northeastern Poland (secondary range) and Lithuania (primary range) was investigated in 2010-2011. Measures of reproductive (number of catkins, number of flowers in catkins) and vegetative traits (height, diameter, number of shoots, vitality) were taken and compared among sexual morphs. In two populations, measurements collected 14 years prior on marked individuals were used to determine the rate of changes in height, crown diameter and survivorship rates. We found trioecy mostly in the secondary part of the range with an average share of hermaphrodites reaching 21% in the trioecious populations. The sex ratio varied between populations, but tended mostly towards female domination. Several traits differed significantly among sexes. The characteristics of hermaphrodites were often intermediate between males and females and provided no evidence for the higher competitive abilities of hermaphrodites. We concluded that the possible gain of hermaphroditism in the colonization process is restricted to reproduction. We consider hermaphroditism in S. myrsinifolia as an equilibrium between the allocation of resources for growth and reproduction in unstable conditions on the margins of the range.
9
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Pierwsze wyniki pozycjonowania GPS trzmielojadów Pernis apivorus gniazdujących na Podlasiu i wnioski z nich płynące dla monitoringu i inwentaryzacji gatunku

63%
Mirski P., Tumiel T.
Ornis Polonica
|
2020
|
tom 61
|
nr 1
10

Central-place foraging in an urban landscape: body mass of common voles (Microtus arvalis Pall.) caught by breeding Kestrels (Falco tinnunculus L.) is positively correlated with availability of hunting sites

51%
Kubacka J., Zmihorski M., Mirski P., Rejt L.
Polish Journal of Ecology
|
2010
|
tom 58
|
nr 2
In the reproduction period a male Kestrel (Falco tinnunculus) is a centralplace forager, i.e. it transports food from hunting grounds to a central location – the nest. A centralplace forager is predicted to take larger or more prey when distance to a foraging site is longer. We studied kestrels breeding in a large Central European city (population 1.7 million), whose main prey are common voles (Microtus arvalis). Kestrel nests are located in the centre and the outskirts, although common voles are scarce in the former. The aim of our study was to analyse the body mass of common voles found in pellets under kestrel nests and relate it to the availability of common vole habitats within 1 km from the nests, controlled for vole frequency in the pellets. We assumed that the greater availability of common vole habitats, the shorter the distance to a foraging site. We found that the body mass of common voles found in pellets was significantly positively correlated with the availability of their habitats, but was not affected by their frequency in pellets. Our results may indicate that, contrary to the central-place foraging rule, and irrespectively of the amount of other prey taken, the kestrels hunted smaller voles when foraging grounds were further away. This might stem from decreased selectivity caused by competition, either in the native territory (due to the high density of kestrels in the centre) or in territories of outskirt kestrels, invaded by city centre kestrels. On the other hand, due to lack of data on the body size of common voles in our study area, the results may suggest that common voles were on average smaller in the centre than in the outskirts. Although the published data do not support the second explanation, more research is needed to verify this.
11

Hybridisation dynamics between the Greater Spotted Eagles Aquila clanga and Lesser Spotted Eagles Aquila pomarina in the Biebrza River Valley (NE Poland)

51%
Maciorowski G., Mirski P., Vali U.
Acta Ornithologica
|
2015
|
tom 50
|
nr 1
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Znaczenie miejsca gniazdowego i przebieg usamodzielniania się młodych bielików z Wigierskiego Parku Narodowego

51%
Mirski P., Anderwald D., Pieczynski P., Zawadzka D.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2018
|
tom 20
|
nr 4[54]
13

Identification of the barrier to gene flow between phylogeographic lineages of the common hamster Cricetus cricetus

45%
Banaszek A., Ziomek J., Jadwiszczak K. A., Kaczynska E., Mirski P.
Acta Theriologica
|
2012
|
tom 57
|
nr 3
In anthropogenically disturbed habitats, natural barriers still exist and have to be recognized, as they are important for conservation measures. Areas of phylogeographic breaks within a species are often stabilized in inhospitable regions which act as natural barriers. An area of contact between phylogeographic lineages of the common hamster (Cricetus cricetus) was found in the Małopolska Upland in Poland. A total of 142 common hamsters were captured between 2005 and 2009. All hamsters were genotyped at 17 microsatellite loci and partial sequences of the mitochondrial (mtDNA) control region were obtained. No mixed populations with mtDNA haplotypes of both lineages were found. The distance between marginal populations was about 20 km; no hamsters were found in the area between. A principal components analysis (PCA) was performed on microsatellite data and the greatest change in PC1 scores was found between marginal samples. To define the habitat components responsible for the phylogeographic break, we compared the habitat composition of sites occupied by hamsters with those from which hamsters were absent. We found that hamsters avoided forested areas and sandy soils. The area of the potential barrier was characterized by a high proportion of woodland and unfavorable soils in comparison with neighboring areas inhabited by hamsters. They cannot settle in this area due to their high winter mortality in shallow burrows and high predation in the fields adjacent to forests.
14

Pokarm polnej populacji blotniaka lakowego Circus pygargus w okresie pisklecym na Nizinie Poludniowopodlaskiej i Mazowieckiej

45%
Mirski P., Krupinski D., Lewtak J., Lewtak M., Menderski S.
Notatki Ornitologiczne
|
2009
|
tom 50
|
nr 1
55-58
15
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Przemieszczenia juwenalnych bielików z Wigierskiego Parku Narodowego po opuszczeniu gniazd

45%
Mirski P., Anderwald D., Lewandowski S., Pieczynski P., Zawadzka D.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2017
|
tom 19
|
nr 4[53]
16

Zimowanie podgatunków kawki Corvus monedula w wybranych miastach Polski

33%
Mirski P., Polakowski M., Budka M., Krolak T., Latkowski M., Michalczuk J., Nagorski P., Rusiecki S.
Ornis Polonica
|
2011
|
tom 52
|
nr 2
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.