Search results for "Feather"
showing 10 items of 38 documents
When the seasons don't fit: Speedy molt as a routine carry-over cost of reproduction
2013
The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which wa…
Physiological stress does not increase with urbanization in European blackbirds: Evidence from hormonal, immunological and cellular indicators
2020
Urbanization changes the landscape structure and ecological processes of natural habitats. While urban areas expose animal communities to novel challenges, they may also provide more stable environments in which environmental fluctuations are buffered. Species´ ecology and physiology may determine their capacity to cope with the city life. However, the physiological mechanisms underlying organismal responses to urbanization, and whether different physiological systems are equally affected by urban environments remain poorly understood. This severely limits our capacity to predict the impact of anthropogenic habitats on wild populations. In this study, we measured indicators of physiological…
Influence of landscape composition and diversity on contaminant flux in terrestrial food webs: a case study of trace metal transfer to European black…
2012
13 pages; International audience; Although understanding the influence of the spatial arrangement of habitats and interacting communities on the processes of pollutant flux and impacts is critical for exposure and risk assessment, to date few studies have been devoted to this emergent topic. We tested the hypothesis that landscape composition and diversity affect the transfer of trace metals to vertebrates. Bioaccumulation of Cd and Pb in blood and feathers of European blackbirds Turdus merula (n=138) was studied over a smelter-impacted area (Northern France). Landscape composition (type and occurrence of the different habitats) and diversity (number of different habitat types and the propo…
Marine debris ingestion in loggerhead sea turtles, Caretta caretta, from the Western Mediterranean
2002
Marine debris represents an important threat for sea turtles, but information on this topic is scarce in some areas, such as the Mediterranean sea. This paper quantifies marine debris ingestion in 54 juvenile loggerhead sea turtles (Caretta caretta) illegally captured by fishermen in Spanish Mediterranean waters. Curved carapace length was measured, necropsies were performed and debris abundance and type was recorded. Different types of debris appeared in the gastrointestinal tract of 43 turtles (79.6%), being plastics the most frequent (75.9%). Tar, paper, Styrofoam, wood, reed, feathers, hooks, lines, and net fragments were also present. A regression analysis showed that the volume of deb…
Repeatability of Feather Mite Prevalence and Intensity in Passerine Birds
2014
Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and appro…
Different Scales of Spatial Segregation of Two Species of Feather Mites on the Wings of a Passerine Bird
2011
The "condition-specific competition hypothesis" proposes that coexistence of 2 species is possible when spatial or temporal variations in environmental conditions exist and each species responds differently to those conditions. The distribution of different species of feather mites on their hosts is known to be affected by intrinsic host factors such as structure of feathers and friction among feathers during flight, but there is also evidence that external factors such as humidity and temperature can affect mite distribution. Some feather mites have the capacity to move through the plumage rather rapidly, and within-host variation in intensity of sunlight could be one of the cues involved …
Lekking in the black grouse— a test of male viability
1991
LEKS, where males congregate to display and females attend only to mate, present one of the most remarkable outcomes of sexual selection1. It is a common but untested belief that females mate with the most vigorous males2. In leks of the black grouse Tetrao tetrix, males dominant in winter flocks were most successful in mating, as were males winning fights over female dummies placed at territory boundaries. Males tear feathers from each others' tail ornaments in combats, and attractive males always had undamaged tails. We report here that by choosing victorious males, females mate with males that are most likely to survive the following six months. There is a strong association between fema…
The methane production of poultry slaughtering residues and effects of pre‐treatments on the methane production of poultry feather
2003
The biological methane production rate and yield of different poultry slaughtering residues were studied. Poultry offal, blood, and bonemeal were rich in proteins and lipids and showed high methane yields, 0.7-0.9, 0.5, and 0.6-0.7 m3 kg(-1) volatile solids(added), respectively (270-340, 100, and 150-170 m3 ton(-1) wet weight). Blood and bonemeal produced methane rapidly, whereas the methane production of offal was more delayed probably due to long-chain fatty acid inhibition. The length of delay depended on the source and concentration of inoculum and incubation temperature, sewage sludge at 35 degrees C having the shortest delay of a few days, while granular sludge did not produce methane…
Diversity and distribution of feather lice on Greater Flamingoes (Phoenicopterus ruber roseus) in the Camargue, southern France
2002
Feather lice were collected from 2S0 chicks of the Greater Flamingo (Phoenicopterus ruber roseus Pallas) captured alive in the Camargue, southern France, in July 1997. Five louse species were identified: Colpocephalum heterosoma Piaget, Colpocephalum salimalii Clay and Trinoton femoratum Piaget of the family Menoponidae; Anaticola phoenicopteri (Coinde) and Anatoecus pygaspis (Nitzsch [in Giebel]) of the family Philopteridae. Our collecting results also show that there is body-site segregation among the several louse species inhabiting the same host individual.
The Moss Biomonitoring Method and Neutron Activation Analysis in Assessing Pollution by Trace Elements in Selected Polish National Parks
2020
The concentrations of trace elements in feather moss Pleurozium schreberi (Brid.) Mitt. were used to indicate the relative levels of air pollution by trace elements in Polish national parks. Pleurozium schreberi was collected from nine national parks. The highest concentrations were recorded in the moss samples from the southern and most industrialised part of the country; the lowest from northern and north-eastern Poland. A comparison of data obtained from Polish national parks in the 1970s and 1990s showed a significant decrease in the concentrations of heavy metals. In the linear covariability estimation, the t quantile approach was used for multi-element comparison. A number of positive…