Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 2

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  breeding density
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
Urbanization affects the ecological and behavioral traits of various species of animals, including birds.We present results concerning long-term fluctuations in breeding densities of nest-box populations of the Blue Tit Cyanistes caeruleus and the Great Tit Parus major in two, structurally and floristically contrasting types of habitat (an urban parkland and a rich deciduous forest) located 10 km apart, in central Poland. This study was conducted in 1999–2012 in the parkland site and in 2002–2012 in the forest site. We found a strong correlation of year-to-year changes in breeding densities of Great Tits between the parkland site and the forest site and a lack of such a correlation in Blue Tits. Breeding densities of Great Tits were much higher in the parkland than in the forest area every year during the study period. Annual changes in breeding densities were not correlated between the species studied. The North Atlantic Oscillation Index (NAO-winter index) tended to influence the density dynamics of the two bird species in the forest area but not in the parkland area.
EN
If two related species come into contact, it could be expected that, in order to coexist, they will either shift their niches apart from each other or one species will replace the other in the course of ever growing competition. Recently, two starling species, the indigenous Red-winged Starling and the exotic European Starling, came into contact in some places in Lesotho (southern Africa). In this paper, some breeding parameters of these species have been compared in an area of their co-occurrence. Studies were carried out in an urbanised habitat in Lesotho, in four consecutive breeding seasons (August-March) during the years 1998-2001. The average density of the Redwinged Starling was 13.8 pairs 100 ha[^-1], while that of the European Starling was 9.3 pairs 100 ha[^-1]. The proportion of the Red-winged Starling to European Starling breeding pairs (1.0:0.7) was strikingly constant over the four consecutive breeding seasons. Most Red-winged Starling breeding territories (78%, N = 56) were located within builtup areas, while most European Starling territories were located either within built-up areas (25%) or on the border of built-up areas and open areas (59%, N =41). Most Red-winged Starling nests (96%) were situated in buildings (N = 46), while European Starling nests were located both in tree holes (43%) and in buildings (57%, N = 28). Both starling species show high nest site tenacity. The Red-winged Starling daily activity pattern during the nestling phase differed considerably from that of the European Starling. Although both starling species do not overlap their feeding niches and daily and seasonal activities, their sympatric occurrence in urbanised habitats may be limited, if suitable nesting sites are lacking.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.