Wyniki wyszukiwania - BazTech

1

Symbol Ateny nie tylko w Atenach

Nawrot Radosław

Zieleń Miejska

|

2022

|

Nr 1

30--31

PL

Mówi się, że miasta wyciągają ze wsi jej mieszkańców – kiedyś dotyczyło to ludzi, teraz to samo możemy powiedzieć o zwierzętach. Wieloletni wieśniacy przenoszą się do miast, czego najlepszym przykładem jest mała sowa – pójdźka.

2

High population density of Little Owl (Athene noctua) in Hortobagy National Park, Hungary, Central Europe

Šálek M., Chrenková M., Kipson M.

Polish Journal of Ecology

|

2013

|

Vol. 61, nr 1

165--169

EN

Little Owl is a rapidly declining farmland species across Central Europe, however its population status is poorly known in Hungary. The main aim of this study was to determine the distribution and population density of Little Owl in Hortobagy National Park (northeastern Hungary), which is characterized by a high proportion of grassland habitats. During March and April of 2011–2012, the Little Owl occurrence was surveyed using tape-recorded stimulation in 245 sampling points in an area of 489 km2. In total, we recorded 245 calling males with relative positive occurrence of 75.5% in an individual sampling point. The average nearest neighbour distance of two calling males was 553.6 meters (min. = 70 m, max. = 3100 m). The average population density of Little Owls was 5.01 calling males/10 km2, however this could reach up to 85.97 calling males/10 km2 in 3.06 km2 locally. Residential buildings and farms were the main expected breeding places in our study area. High density of the Little Owl in the study area is probably influenced by traditional pastoral management, extensive agriculture and high proportion of grasslands. The particualar role could be atributed to presence of short-sward pastures around human settlements, considered to be crucial for the species survival in Central Europe. Further monitoring of the Little Owl is necessary to assess its current population status across various parts of its distribution range.

3

Fast method for fractionation of lipids and related non-polar substances from birds’ feathers using thermostated micro-TLC

Baran M. J., Zarzycki P. K.

Camera Separatoria

|

2011

|

Vol. 3, No. 1

221--227

EN

Planar chromatography (TLC) is known as an effective tool for separation of complex biosamples highly loaded with interfering substances. The main goal of this research communication is to demonstrate a capability of micro-TLC methodology followed by simple one-step liquid extraction as fast fractionation tool for wide range of non-polar, low-molecular mass substances extracted from birds’ feathers samples. The main analytical problem concerning birds’ feathers is the presence of interfering matrix, mainly composed of waxes-like impurities. Such substances can be strongly adsorbed on the stationary phase. Proposed simple extraction protocol and fast micro-TLC separation procedure is based on dichloromethane: methanol mixtures. We used this methodology for fractionation of non-polar compounds present in feathers of buzzard, cormorant and little owl. Described methodology can be applied for fast fractionation or screening of whole range of target substances as well as chemo-taxonomic studies and fingerprinting of complex mixtures, which are present in raw biological samples. Particularly, the micro-TLC separation combined with PMA staining and UV light detection seems to be an effective tool for fast and low-cost characterization of non-polar compounds from birds’ feathers or uropygial gland secretion products.

PL

Pióra, ze względu na powszechną obecność ptaków w różnych typach środowisk, mogą znależć zastosowane jako materiał do badań biomonitoringowych. Wymaga to opracowania ekstrakcji niepolarnych związków zawartych w upierzeniu oraz metody ich skutecznego rozdzielania z wykorzystaniem technik chromatograficznych. Zasadniczym problemem analitycznym jest obecność w piórach substancji o charakterze wosków, które bardzo silnie oddziaływują z chromatograficzną fazą stacjonarną na bazie krzemionki lub oktadecylsilanu. Adsorbenty te powszechnie stosowane jako fazy stacjonarne w technikach cienkowarstwowych kolumnowych. Głównym problemem jest to, iż naniesienie na kolumnę chromatograficzną nieodpowiednio oczyszczonych ekstraktów próbek biologicznych zawierających woski jako zanieczyszczenia, zazwyczaj prowadzi do jej zniszczenia. Zaletą chromatografii planarnej jest w tym przypadku to, że dana płytka jest wykorzystywana do rozdzielania tylko raz. Celem niniejszej pracy było opracowanie szybkiej procedury analitycznej z wykorzystaniem prostej jednoetapowej ekstrakcji cieczą oraz rozdzielania uzyskanych ekstraktów substancji niepolarnych obecnych na powierzchni piór ptaków, za pomocą mikropłytek chromatograficznych. Uzyskane wyniki wskazują na przydatność metodologii ekstrakcji cieczą oraz detekcji fluorescencyjnej w badaniach chemotaksonomicznych oraz biomonitoringu.

4

Population decline of the Little Owl (Athene noctua)in the Czech Republic

Salek M., Schropfer L.

Polish Journal of Ecology

|

2008

|

Vol. 56, nr 3

527-534

EN

A change of land use is often cited as a causal factor in the decline of many species of farmland birds. Populations of the Little Owl (Athene noctua Scop., 1769) have notably decreased throughout Europe in the last 60 years, including the Czech Republic. The aims of this study were to estimate the recent population trend of the Little Owl and to analyze the importance of altitude and grassland habitat within Little Owl territories. The population trend of the Little Owl in the Czech Republic has still decreasing tendency. The population density dropped from 0.33 breeding pairs (bps) 10 km[^-2] to 0.12 bps 10 km[^-2] in the first (1993-1995) and second (1998-1999) monitoring program, respectively. The decline is apparent also from results from last Little Owl monitoring program which were carried out in 2005.2006 on 35 study plots (4607 km[^2]). The average population density was estimated at 0.1 bps 10 km[^-2]. A distinct feature of these recent populations is that they occur in the places with relatively high local density (core areas) in comparison to the surroundings, which are unoccupied. At present, the Little Owl rarely breeds in natural tree cavities, but rather the majority of nesting sites are situated in human artifacts, especially within agricultural objects. Areas in which the Little Owl occurs have a significantly larger proportion of grasslands and are situated at lower altitudes. We suggest that the changes in agricultural landscape associated with disappearance of traditional farming management of grassland habitats, forceful pasturage and regular mowing were the main factors in this long-term population decline. The recent decrease of Little Owls could be also the consequence of the existence of small isolated populations in which mortality is not balanced by immigration from surrounding areas.

5

Long-term decline of the Little Owl (Athene noctua Scop., 1769) in Central Poland

Żmihorski Michał, Altenburg-Bacia Daria, Romanowski Jerzy, Kowalski Marek, Osojca Grzegorz

Polish Journal of Ecology

|

2006

|

Vol. 54, nr 2

321-324

EN

The population of Little Owl decreased over much of Europe including Poland, where it's status has not yet been elucidated in full. We compiled data from 13 censuses carried out from 1982-2005 at a 12 km2 study plot situated in an agricultural area in the north-western outskirts of warsaw in Central Poland. We observed a significant decline in the Little Owl population, leading to its disappearance from the study site. The population dynamics was not correlated with the weather factors analysed (snow cover and thickness, air temperature for December-March period, precipitation for March, May and June), which indicates that climate change was not a direct cause of the decline. There were no substantial changes in the land use structure at the study area. We conclude that the reduction in nesting sites and decreased food availability are the potential factors of the Little Owl decline.