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Weather and climatic conditions may impact on many aspects of bird populations, including population size, the timing of breeding and synchrony between these variables in local populations. We examined synchrony in population size and the laying date of two starling Sturnus vulgaris populations 25 km apart, at Ohau and Belmont, in New Zealand. Data were collected in nest-boxes in both study plots from 1970 to 2003. Additionally we investigated possible relationships with a large geographical climate index, the El Niño Southern Oscillation (ENSO). Starlings at Ohau bred significantly earlier than at Belmont. The difference in the median of year median date of laying the first egg was 3 days. Simultaneously, the percent of nest boxes used by birds was much higher in Ohau (86%, SE = 4.1) than in Belmont (52%, SE = 2.9). However, we did not find a significant relationship between median dates of laying and the percent of nest boxes used by birds in each breeding season in the two populations. Furthermore, we found no influence of ENSO on (potential) synchrony in starlings’ breeding parameters. We suggest that lack of synchrony between two close local populations, both in percentage of occupied nest boxes and time of laying, is due to starlings responding to very local conditions, like food availability. We urge future studies to take advantage of spatially close populations.
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.
Three new quill mite species of the genus Aulonastus Kethley, 1970 (Acari, Syringophilidae) from passerine birds are described: A. buczekae sp. nov. from the common starling Sturnus vulgaris (Passeriformes, Sturnidae); A. lusciniae sp. nov. from the thrush nightingale Luscinia luscinia (Passeriformes, Turdidae) and A. albus sp. nov. from the pied wagtail Motacilla alba (Passeriformes, Motacillidae). Key to all know species of the genus Aulonastus is given.
The influence of coccidia on starling nestlings was analyzed. Isospora sp. was found in 67% of starling broods. Although some broods were heavily infected with Isospora sp., nestlings from most infected nests were on average heavier and had longer wings than nestlings from low infection and non-infected nests. Apparently, nestlings that were better fed, had also greater chance of being infected with Isospora sp. These results suggest that coccidia affect the growth of starling nestlings - and, although not pathogenic, may affect the reproductive success of starlings, especially when the parental feeding effort could not be sustained.
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