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  • Author: Krzysztof Kaczmarek x
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Fifteen years of the Common Snipe (Gallinago gallinago) study at the Jeziorsko reservoir with some notes about weight and moult

The Students's Section from University of Łódź organises ringing camp at the dam reservoir every year. The aim of the camp is wader and duck ringing. One of the most numerous species of bird ringed is the Common Snipe. During 15 years (1989-2003) of studies 4142 individuals of this species were ringed. Age ratio differed among years, but every year young birds represented more that 80% of all ringed individuals. Snipes caught in September caused problems with age identification and that impeded to obtain correct age ratio each year. Analysis of weight of caught birds revealed between-years variation in juvenile birds, adults were excluded from analysis due to small sample size. Throughout the autumn months the increase in mean body mass in young birds was observed. Data about moult suggest that adult birds show two main strategies of primary moult: traditional moult and suspended moult. Both of them are of the same frequency. Tail feathers are moulted by juveniles as well as by adults simultaneously.

Sexing Common Snipe (Gallinago gallinago) in the Field - is there any Simple Method?

There are a few methods used for sex determination in the Common Snipe. However, all proposed methods are based on data obtained from dead birds. The most important feature is the total length of the outermost tail feather. The performed analysis showed that the vane length was strongly correlated with the total length of this feather. It allowed to predict this measurement having only the vane length. Because the measurement procedure influences the vane length, new ranges of vane length typical for each sex are proposed. However, the analysis of the vane length distribution suggested that there were no two homogenous groups that would represent the two sexes. This supports the prediction that the total feather length should be used rather cautiously as a simple sex trait in the Common Snipe. Also the second trait based on the tail feather colour resulted in overestimation of the proportion of females.

Pattern of Post-Juvenile Moult in Common Snipe (Gallinago Gallinago) and Its Implications for Ageing of the Species

External ageing of Common Snipe (Gallinago gallinago) still engenders considerable problems. To improve precision of age determination on the basis of plumage characteristics a scheme of post-juvenile moult was investigated in approximately 1200 first-year Common Snipes caught during autumn migration in central Poland. Post-juvenile moult was commenced from body feathers followed by moult of rectrices, lesser/median wing coverts and tertials. Moult sequence showed high inter-individual variability and was started in rectrices (36.9%), wing coverts (25.3%), tertials (8.4%) or simultaneously in several of these tracts of feathers (29.4%). Moult of rectrices was finished before completion of moult of wing coverts and tertials. Moult of tertials finished as the last from all age-indicative tracts of feathers. Consequently, tertials were suggested as the most useful for ageing of first-year Common Snipes in an advanced stage of moult. There was no case of moult of the outermost tertial in first-year birds. The second tertial from distal side of wing was moulted as the last one within this tract of feathers and thereby should be of special interest during plumage examination.

Abstract

The experiment was performed on 60 crossbred weaners with average initial body weight (BW) of 22 kg. The animals were divided into 4 groups, with 15 animals (10 males and 5 females) per group, based on the percentage content of the following components in complete diets: soybean meal, toasted full-fat soybeans, cold-pressed rapeseed cake with increased oil content, extruded rapeseed cake with increased oil content. The growth performance of pigs, carcass characteristics, meat quality and the fatty acid profile of depot fat were determined. The pigs fed complete diets containing toasted soybeans had higher average daily gain (ADG). The animals receiving cold-pressed rapeseed cake were characterised by lower ADG and higher FCR. The carcasses of pigs fed diets containing cold-pressed rapeseed cake and extruded rapeseed cake had lower lean content than the carcasses of pigs administered toasted soybeans. The analysed feedstuffs had no effect on back-fat thickness or meat quality. Cold-pressed and extruded rapeseed cake contributed to changes in the fatty acid profile of backfat, including an increase in the concentrations of monounsaturated fatty acids (MUFAs) and a more desirable n-6/n-3 PUFA ratio. The extrusion processing of rapeseed cake decreased the content of lysine and methionine with cystine by approximately 4%, and reduced total glucosinolate content by approximately 17%. The inclusion of toasted soybeans in pig diets contributed to higher BW gain and carcass dressing percentage. Rapeseed cake with increased oil content led to desirable changes in the fatty acid profile of backfat.

Abstract

The aim of this paper is to check whether mathematical competences influence some manifestations of bounded rationality. A special example of bounded rationality called “framing effect” is dealt with to analyze empirically the thesis that mathematical competences and cognitive effort may reduce the framing effect. Two kinds of cognitive effort: probabilistic and deductive are analysed. Experiments were conducted using samples of Polish students, both mathematically and business oriented. As an example of a framing situation an example called “Asian disease”, (the first analyzed and the most popular example of the framing effect), is considered. The thesis that a mathematical background may diminish the occurrence of the framing effect was partly confirmed.

Abstract

River bank filtration (RBF) is a system that enriches groundwater resources by induced infiltration of river water to an aquifer. Problematic during operation of RBF systems is the deterioration of infiltration effectiveness caused by river bed clogging. This situation was observed in the Krajkowo well field which supplies fresh water to the city of Poznań (Poland) during and after the long hydrological drought between the years 1989 and 1992. The present note discusses results of specific hydrogeological research which included drilling of a net of boreholes to a depth of 10 m below river bottom (for sediment sampling as well as for hydrogeological measurements), analyses of grain size distribution and relative density studies. The results obtained have allowed the recognition of the origin of the clogging processes, as well as the documentation of the clogged parts of the river bottom designated for unclogging activities.

Fieldwork results of wader research stations working in Poland in 2002-2003

Abstract

The aim of this study was to evaluate the fruit quality of 13 Asian pear cultivars grown in climatic conditions of central Poland. The following cultivars were tested: ‘Chojuro’, ‘Hayatama’, ‘Hosui’, ‘Kosui’, ‘Yuan Huang’, ‘Nijisseiki’, ‘Dżin Li’, ‘Er Shi Shinge’, ‘Er Jang Li’, ‘Golden 20th’, ‘Min Czi Li’, ‘San Li’, and ‘Shinseiki’. Pears were harvested in Experimental Orchard of Research Institute of Horticulture in Dąbrowice (near Skierniewice). Fruits were stored for 10 weeks at 0 °C in regular atmospheric conditions. Flesh firmness (FF), total soluble solids (TSS), and titratable acidity (TA) were measured at harvest and after the storage followed with 1 and 7 days of shelf life (SL) at 18 °C. After the storage, the sensory evaluation was also performed. Among the tested cultivars, ‘Min Czi Li’ and ‘San Li’ were the most firm (above 45 N) and ‘Kosui’ was the least firm (below 28 N) at harvest time. High amount of TSS (above 11% in both seasons and harvest dates) was observed in ‘Chojuro’, ‘Hayatama’, ‘Kosui’, ‘Yuan Huang’, and ‘Er Jang Li’ pears. Low TSS (not more than 10.6% at harvest) was observed in ‘Nijisseiki’, ‘Dżin Li’, and ‘Er Shi Shinge’ cultivars. The large differences among cultivars were observed in TA. High TA was observed in ‘Nijisseiki’ (above 0.32% in all terms of analyses) and low TA in ‘Hayatama’ and ‘Kosui’ (below 0.14%). All of the evaluated cultivars can be stored for 10 weeks at 0 °C in regular atmosphere without major negative impact on their quality characteristics. Fruits showed a slight (sometimes significant) decrease in FF after storage and a slight or no changes in TSS and TA. In sensory evaluations, ‘Chojuro’, ‘Hayatama’, ‘Hosui’, ‘Kosui’, ‘Yuan Huang’, ‘Er Jang Li’, ‘Er Shi Shinge’, and ‘Shinseiki’ (mostly cultivars characterized by high TSS) obtained highest scores for the overall quality (above 5.0 points in 10 points scale).

Abstract

The aim of the study was to compare the sensory quality of scab resistant ‘Topaz’ apples grown in certified organic orchards (ECO) with those grown in orchards managed within integrated method (IP), and to determine their potential processing suitability. Fruits were harvested in five certificated IP and ECO orchards at the optimum ripeness stage and stored for two months in normal atmosphere at 1 ºC. Apple quality was assessed one day after cold storage and after 7 days of storage at the temperature 18 ºC to simulate shelf life. The results of taste and flavour sensory assessment did not explicitly demonstrate the effect of the orchard management system on the overall eating quality. Although the fruits from the organic orchards were perceived as less sweet and sourer, the management system did not influence the overall eating quality. There was no effect of the growing technology on quality traits connected with aroma and overall texture assessment. Regarding appearance evaluation, fruits from organic orchards were characterized by a higher variation in shape and size, and more frequently than in the case of IP apples had blemishes, scars and rust, which negatively affected their attractiveness. Analysis of the chemical composition of fruits indicates that apples from organic orchards are characterized on average by higher titratable acidity and higher soluble solids content than apples from IP orchards, which could favour their potential application as the additive regulating acidity and shaping the desirable sensory traits of processed organic products.