Search results for "Feather"
showing 10 items of 38 documents
Iridescent structurally based coloration of eyespots correlates with mating success in the peacock.
2007
Gaudy plumage coloration is a widespread ornamental trait in birds and thought to be sexually selected. Although much attention has been devoted to structural coloration reflecting in UV, the signaling function of structural colors lacking UV reflectance and those that exhibit iridescence coloration are poorly documented. The train of the peacock (Pavo cristatus), a classical example of a sexually selected trait, is composed of iridescent structurally colored eyespots not reflecting in UV. Until today, the role played by the structural color of the eyespots in female mate choice has never been investigated using spectrometry. We measured eyespot coloration from a stationary angle (static co…
The importance of the moss layer in sustaining biological diversity of Gamasina mites in coniferous forest soil
2008
Summary The feather moss layer of boreal coniferous forests is known to buffer the underlying soil temperature and to be a major component in the nitrogen and phosphorus cycles by efficient scavenging of nutrients from throughfall and direct precipitation. Through indirect or direct effects the feather moss layer may also play a significant role in forming soil organism communities. In this 4-year experimental field study, the predatory Gamasina mite diversity was estimated in plots where the feather moss layer was removed or disturbed by turning over, in relation to that in control plots. Species richness, Shannon's diversity and equitability in spring but not autumn were decreased when th…
Seasonal changes in some thermoregulatory variables of the house sparrow (Passer domesticus L.)
1975
Abstract 1. The body weight, plumage, insulation, oxygen consumption and body lipids were studied seasonally in the house sparrow, Passer domesticus L. 2. The weights of body and plumage were greater in autumn and winter than in summer. 3. The insulative property of the plumage was better in autumn and winter birds than in summer birds. 4. The oxygen consumption of young birds was higher than that of plucked and adult birds. 5. The amount of subcutaneous depot fat tissue and its lipid content was greatest in autumn. The C18-unsaturated fatty acids were most prominent in the subcutaneous fat. Palmitic acid was the most prevalent fatty acid in the liver. The relative amount of C18-unsaturated…
A Trade-Off Between Current Reproduction and Moult in the Pied Flycatcher- an Experiment
1994
1. Mechanisms causing costs of reproduction in birds are poorly understood. Here we focus on the renewing of feathers (= moult) which may be a possible physiological link between successive breeding attempts. 2. We performed clutch size manipulations to study whether the reproductive effort of the Pied Flycatcher (Ficedula hypoleuca) has any effect on the initiation and progress of the moult in the late nesting period. 3. The absolute timing of breeding did not affect the onset of parents' moult, i.e. latebreeding individuals did not start moulting before nestlings were fledged more frequently than early ones. This indicates that moult was closely related to the breeding schedule of each in…
Wing feather moult and age determination of Snowy Owls Bubo scandiacus.
2012
Moult of primary and secondary flight feathers of Snowy Owls Bubo scandiacus was studied from 53 museum specimens retaining some juvenile feathers. There were no ringed Snowy Owls of known age in the skin material, and the moult pattern has thus been interpreted using the moult of Eagle Owls Bubo bubo as a model. The difference between juvenile and adult primaries is described. Greater coverts may facilitate age determination of single flight feathers. Snowy Owls start their first flight feather moult M1 by shedding the innermost 2-6 secondaries during their second summer (as 2C birds). A majority of the owls also shed primary P7 during this first moult, occasionally also P8. This moult pro…
Ptiliolum marginatum (Aube, 1850) (Coleoptera: Ptiliidae)– gatunek nowy dla Polski z Białowieskiego Parku Narodowego
2021
We present the first record of Ptiliolum marginatum for Poland. The specimens have been extracted from two nests of the wood warbler Phylloscopus sibilatrix in 2020, during investigations of the invertebrate fauna inhabiting bird nests. The samples were collected in the strictly protected part of the Białowieża National Park, in eastern Poland. We provide general information on the geographical distribution of Ptiliolum marginatum in Europe, the state of knowledge of the genus Ptiliolum in Poland, and further documentation including colour photographs of dorsal and ventral habitus, and characteristic features of hind femora and spermatheca of females.
An exploration of isotopic variability in feathers and claws of Lesser Kestrel Falco naumanni chicks from southern Sicily
2016
Stable isotopes are nowadays commonly used in the study of many key features of avian ecology. However, the adequate choice of what isotopic ratio to consider and what tissues to sample for assessing specific questions may be tricky. Here, we explored the variation in a suite of stable isotope ratios (δ13C, δ15N, δ34S, δ2H, δO) in the feathers and claws of chicks of Lesser Kestrels Falco naumannifrom south-eastern Sicily (Italy) sampled throughout colonies of the same population but surrounded by different habitats. Ouraimsare to provide an insight into the isotopic ecology of Lesser Kestrel and to provide methodological indications for futurestudies.Specifically,we tested whether stable is…
Body Size and Immune Defense of Nestling Blue Tits (Cyanistes caeruleus) in Response to Manipulation of Ectoparasites and Food Supply
2011
ABSTRACT. A developing organism faces a dilemma: whether to allocate available resources to building its body structures (growth) or to the development of its immune system. The outcome of this tradeoff is likely to be modified by parasites. We manipulated the abundance of ectoparasitic Hen Fleas (Ceratophyllus gallinae) on nestling Blue Tits (Cyanistes caeruleus) by microwaving nests and subsequently adding 200 Hen Fleas (15 infested nests) or not (16 reduced-infestation nests). In addition, we manipulated the host nestlings' food resources by supplementary feeding 10–15% of daily energy needs to half the nestlings in a nest during the key developmental period (days 2–12). Feather growth (…
Carry-over effects of conditions at the wintering grounds on breeding plumage signals in a migratory bird : roles of phenotypic plasticity and select…
2016
To understand the consequences of ever-changing environment on the dynamics of phenotypic traits, distinguishing between selection processes and individual plasticity is crucial. We examined individual consistency/plasticity in several male secondary sexual traits expressed during the breeding season (white wing and forehead patch size, UV reflectance of white wing patch and dorsal melanin coloration) in a migratory pied flycatcher (Ficedula hypoleuca) population over an 11-year period. Furthermore, we studied carry-over effects of three environmental variables (NAO, a climatic index; NDVI, a vegetation index; and rainfall) at the wintering grounds (during prebreeding moult) on the expressi…
Color Signals in the Black Grouse (Tetrao tetrix): Signal Properties and Their Condition Dependency
2009
Recent progress in techniques of quantifying between-individual differences of color-based ornaments has revealed undiscovered possibilities for research in sexual selection. We present how the color spectra data can be comprehensively used for studying the importance of sexual ornaments in the black grouse and how these ornaments are related to a male condition. For this, we used both correlative field and experimental data. Field data indicated that older males had more chromatic coloration than yearlings. Blue chroma of males was correlated with male mating success. We experimentally manipulated yearling birds with testosterone implants and found that testosterone-implanted males had imp…