Trace element analysis of turkey vulture (Cathartes aura) feathers

Ten feather samples, including primary and secondary flight and tail feathers, were analysed for the trace element composition of vane and rachis structures using instrumental neutron activation analysis (INAA), inductively coupled plasma-mass spectrometry (ICP-MS), and cold vapour atomic absorption spectroscopy (CVAAS). Five environmentally significant elements, Cr, As, Se, Sb and Hg, were analysed by INAA and ICP-MS/CVAAS. A further seventeen elements were analysed by ICP-MS. The majority data obtained by INAA and ICP-MS/CVAAS were not statistically significantly different (p = 0.05), although the removal of isobaric interferences using dynamic reaction cell technology was essential to produce ICP-MS data that were consistent with INAA for Cr, As and Se. Significantly higher trace element concentrations were observed for vane relative to rachis for all elements, except Cu and Hg. These elements displayed vane/rachis ratios of 0.7 ± 0.2 and 1.0 ± 0.2, respectively. In general, vane and rachis subgroups afforded data that were consistent with a normal distribution, with RSDs in the range (12–83) % for INAA analyses. A total of 18 outliers were noted amongst the various feather, structure, element combinations, with 14 outliers being observed in the vane and/or rachis structures of the same tail feather. Given the significant differences in vane and rachis concentrations observed for many elements, the large RSDs reported for elements and the potential for outliers, the determination of environmental trace element burden using feathers is significantly enhanced by the analysis of multiple feathers using INAA.     

Black and white – does melanin change the bulk carbon and nitrogen isotope values of feathers?

Bird feathers are employed in a wide range of carbon and nitrogen isotope studies relating to diet and migration. Feathers are chemically inert with respect to carbon and nitrogen, after synthesis. It has always been assumed that feathers show isotope values characteristic of keratin, a fibrous structural protein from which they are formed. Little attention has been paid to other components of feathers such as melanin or carotenoids. Melanin is synthesized from tyrosine, which is depleted in both ¹³C and ¹⁵N. We compared isotope values of coeval black and white feathers in four different species. Black feather parts were in all cases significantly depleted in ¹³C relative to white feather parts but in most species no clear trend was discernable for ¹⁵N. We suggest that additional evaluation may be required to characterize the carbon and nitrogen isotope contribution of feather pigments like carotenoids. Care should be taken in future stable isotope studies when comparing differently coloured feathers. Copyright © 2010 John Wiley & Sons, Ltd.     

Stable-hydrogen isotope heterogeneity in keratinous materials: mass spectrometry and migratory wildlife tissue subsampling strategies

Stable-hydrogen isotope measurements (deltaD) of biological tissues have gained widespread acceptance in wildlife and forensic studies, especially in tracking geographical movements of birds and other species. Continuous-flow isotope-ratio mass spectrometry enables high-throughput deltaD analyses to be conducted on tissue samples as small as 0.15 mg, compared with conventional offline analyses that require 7-10 mg. This reduction in sample size has raised concerns regarding intra-sample hydrogen isotopic variance due to potential biological heterogeneities that could exceed interpretations of geospatial origin. To help resolve this, feathers were obtained from captive birds to examine isotopic variance expected due to sample size, location, and heterogeneity factors, and from selected wild birds to examine isotopic variance due to these and to additional dietary or location changes during feather growth. Captive bird feathers were sub-sampled along the vane on either side of a single feather at masses of 0.25, 0.35, 0.45, 0.6, 1.0 and 2.0 mg, and along the rachis. The results showed consistency of feather deltaD measurements across a wide range of sample masses. Within-feather deltaD isotopic variance for captive and some wild birds was as low as +/-3 per thousand for vane material, which corresponds to a geospatial resolution of about 1 degree of latitude in central North America. Intra-sample variance for the rachis was +/-5 per thousand, with lower deltaD values for both wild and captive birds. However, given the extraordinary intra-feather deltaD variance observed in some wild species, we recommend researchers first carefully assess the degree of intra- and inter-sample hydrogen isotopic variation in the selected tissue growth period for the species of interest before geospatial interpretations of origin are attempted.     

Biological Pretreatment of Chicken Feather and Biogas Production from Total Broth

Chicken feathers are available in large quantities around the world causing environmental challenges. The feathers are composed of keratin that is a recalcitrant protein and is hard to degrade. In this work, chicken feathers were aerobically pretreated for 2–8 days at total solid concentrations of 5, 10, and 20 % by Bacillus sp. C₄, a bacterium that produces both α- and β-keratinases. Then, the liquid fraction (feather hydrolysate) as well as the total broth (liquid and solid fraction of pretreated feathers) was used as substrates for biogas production using anaerobic sludge or bacteria granules as inoculum. The biological pretreatment of feather waste was productive; about 75 % of feather was converted to soluble crude protein after 8 days of degradation at initial feather concentration of 5 %. Bacteria granules performed better during anaerobic digestion of untreated feathers, resulting in approximately two times more methane yield (i.e., 199 mlCH₄/gVS compared to 105 mlCH₄/gVS when sludge was used). Pretreatment improved methane yield by 292 and 105 % when sludge and granules were used on the hydrolysate. Bacteria granules worked effectively on the total broth, yielded 445 mlCH₄/gVS methane, which is 124 % more than that obtained with the same type of inoculum from untreated feather.     

Pretreatment of Chicken Feather Waste for Improved Biogas Production

This study deals with the utilization of chicken feather waste as a substrate for anaerobic digestion and improving biogas production by degradation of the compact structure of the feather keratin. In order to increase the digestibility of the feather, different pretreatments were investigated, including thermal pretreatment at 120 °C for 10 min, enzymatic hydrolysis with an alkaline endopeptidase [0.53–2.66 mL/g volatile solids (VS) feathers] for 0, 2, or 24 h at 55 °C, as well as a combination of these pretreatments. The effects of the treatments were then evaluated by anaerobic batch digestion assays at 55 °C. The enzymatic pretreatment increased the methane yield to 0.40 Nm³/kg VS_added, which is 122 % improvement compared to the yield of the untreated feathers. The other treatment conditions were less effective, increasing the methane yield by 11–50 %. The long-term effects of anaerobic digestion of feathers were examined by co-digestion of the feather with organic fraction of municipal solid waste performed with and without the addition of enzyme. When enzyme was added together with the feed, CH₄ yield of 0.485 Nm³/kg VS^?1 d^?1 was achieved together with a stable reactor performance, while in the control reactor, a decrease in methane production, together with accumulation of undegraded feather, was observed.     

Variability in the chemical contamination effects of gun shot

This is a contribution to a larger study aimed at development of a technique to determine the origins of waterfowl from their feather chemistry, using automated X-ray fluorescence spectrometry. Since feather samples commonly come from shot birds, an effort was made to measure the contamination effects of shot using cotton cloth to simulate feathers. At pointblank ranges contamination can include the elements Ba, Sb, Pb, Cu, S and likely others depending on the exact composition of both gun powder and shot. At greater ranges (12.5 to 50 yards – 14.4 to 45 m) significant contamination resulting from 12 gauge No. 2 shot came only from lead, with some zinc contamination probable at the extreme range used. Lead contamination increased with increasing range, and apparently has a curvelinear relationship with pellet velocity. This knowledge might permit prediction, after the fact, of ranges from which shot has been fired.     

Backtracking the movements of a migratory bird: a case study of a white-fronted goose (Anser albifrons)

The occurrence of avian influenza has brought attention to migrating birds and their migratory routes as possible carriers and gates, respectively, of the pathogenic influenza virus. There is a need to verify migration routes and to back-track the migration routes of infected animals. Stable isotope analysis of bird feathers is a valuable tool for studying the migratory pattern of birds, by gaining information about the environmental conditions during the growth of the feathers. Ideally, if different feathers that have grown during different periods are investigated, not only can information about the molting region be extracted, but also some clues can be obtained about stop-overs during the migration of individual animals, enabling the reconstruction of the pathway. In the presented case study the hydrogen, carbon nitrogen and sulfur stable isotope ratios of different types of feathers (primaries, down feathers and blood pinfeathers) from one white-fronted goose specimen have been determined. These ratios differ significantly for some elements. By taking into account the different time of growth of the respective feathers, the isotope data can be interpreted with respect to the animal migration route from the summer (and molting) to the wintering region. This is the first paper to attempt to map the migration pathway using different types of feather from a single individual.     

Effect of acids on the determination of lead and cadmium by atomic absorption spectrometry

The effect of different mineral acids on the absorption signals of lead and cadmium in atomic absorption spectrometry is reported. The behaviour of the signals was studied with respect to variations in metal concentration, acid concentration, flame stoichiometry and burner height. For the determination of lead and cadmium the most suitable concentrations of hydrochloric, nitric, sulphuric and perchloric acids were 5, 5, 2.5 and 5%, respectively. Similar absorption behaviour was observed in oxidizing and reducing flames for lead and cadmium in all the acids studied.     

Determination of Heavy Metals and Other Water Quality Parameters from the South China Sea

This study investigated the distribution and concentrations of chromium, copper, arsenic, zinc, cadmium, and lead in seawater and suspended particles in the South China Sea by collection of samples from different depths at sixteen stations. The salinity, temperature, pH, dissolved organic carbon, dissolved oxygen, and silicon concentration were also measured in seawater. The results showed that the concentration levels in seawater from 0 m to 4000 m followed this pattern: zinc > arsenic > copper > lead > chromium > cadmium. Significant correlations were observed between lead and chromium and between arsenic, cadmium, and lead at r > 0.728. Very weak correlations were observed between copper and arsenic and between copper and cadmium. The concentrations of dissolved metals and particulate metals had negative correlations except for zinc. The metal concentrations in seawater and suspended particles showed different correlation behavior with salinity, temperature, pH, dissolved oxygen, dissolved organic carbon, and silicon.     

Microsporum fulvum IBRL SD3: As Novel Isolate for Chicken Feathers Degradation

Keratinous wastes have increasingly become a problem and accumulate in the environment mainly in the form of feathers, generated mainly from a large number of poultry industries. As keratins are very difficult to degrade by general proteases, they pose a major environmental problem. Therefore, microorganisms which would effectively degrade keratins are needed for recycling such wastes. A geophilic dermatophyte, Microsporum fulvum IBRL SD3 which was isolated from a soil sample collected from a chicken feather dumping site using a baiting technique, was capable to produce keratinase significantly. The crude keratinase was able to degrade whole chicken feathers effectively. The end product of the degradation was protein that contained essential amino acids and may have potential application in animal feed production. Thus, M. fulvum could be a novel organism to produce keratinase for chicken feathers degradation.