scholarly journals Disentangling causes of the dieback of littoral stands in an overloaded water-bird reserve: roles of eutrophication, fish and geese

2021 ◽  
Author(s):  
Richard Svidenský ◽  
Andrea Kučerová ◽  
Hana Čížková
Keyword(s):  
Sediment Quality ◽  
Bird Species ◽  
Ecological Factors ◽  
Shoot Density ◽  
Field Investigation ◽  
Mineral Nutrient ◽  
Fish Stocks ◽  
Water Bird ◽  
Physico Chemical ◽  
Negative Effect

Abstract European fishponds used for semi-intensive fish production can serve for refuges of water birds if the fish stocks are limited but the effects of other ecological factors on the ecosystem stability are seldom considered. The aim of this study is to elucidate causes of a marked decline of littoral stands dominated with Typha angustifolia in a hypertrophic fishpond forming a part of a valuable water-bird reserve. Field investigation and two experiments were conducted in order to separate the effects of mineral nutrient availability, redox condition, fish and geese. The physico-chemical characteristics of water and sediments confirmed hypertrophic conditions in the fishpond but a follow-up mesocosm experiment did not prove a negative effect of the sediment quality on the plant growth. On the other hand, a field enclosure experiment showed a significant negative effect on shoot density, which was attributed to grazing by geese. An additional damage to plant belowground parts was ascribed to large carp individuals, albeit in small numbers. The study points to a conservation dilemma caused by large numbers of geese destroying littoral stands in a fishpond nature reserve, which then looses its nesting function for other water-bird species.

scholarly journals Causes of the dieback of littoral stands in an overpopulated water-bird reserve: Role of eutrophication, fish and geese

2021 ◽  
Vol 11 (2) ◽  
pp. 79-90
Author(s):  
Richard Svidenský ◽  
Andrea Kučerová ◽  
Hana Čížková
Keyword(s):  
Ecological Factors ◽  
Shoot Density ◽  
Mineral Nutrient ◽  
Ecological Stability ◽  
Anser Anser ◽  
Water Bird ◽  
Nesting Sites ◽  
Negative Effect ◽  
Water Birds ◽  
Greylag Geese

European fishponds can serve as refuges for water birds if the fish stocks are limited, but the effects of other ecological factors on their ecological stability are rarely considered. The aim of this study is to determine the causes of marked dieback of littoral stands dominated by Typha angustifolia L. in a hypertrophic fishpond that is also a valuable water bird reserve. A field study and two experiments were conducted in order to separate the effects of mineral nutrient availability, redox conditions, fish and water birds. The physico-chemical characteristics of the water and sediments confirmed hypertrophic conditions in the fishpond, but a mesocosm experiment did not indicate it had a negative effect on plant growth. On the other hand, a field enclosure experiment showed that in sparse stands, unfenced parts had a significantly smaller shoot density than fenced parts. This was attributed to grazing by greylag geese (Anser anser L.). In addition, damage to belowground parts of plants were ascribed to large individuals of albeit a few large common carp (Cyprinus carpio L.). This study highlights a conservation dilemma as large numbers of geese destroy littoral stands in fishpond nature reserves, which then become unsuitable nesting sites for other species of water birds.

scholarly journals Status and Speciation of Silicon and Its Interaction with Physico-Chemical Properties

2021 ◽  
pp. 1-11
Author(s):  
Isaiah Ufuoma Efenudu ◽  
Ehi Robert Orhue ◽  
Ogochukwu Jennifer Ikeh ◽  
Michael Aimiesomon Erhayimwen ◽  
Blessing James
Keyword(s):  
Organic Matter ◽  
Acidic Medium ◽  
Soil Depth ◽  
Chemical Properties ◽  
Water Soluble ◽  
Sequential Fractionation ◽  
Soil Redox ◽  
Parent Materials ◽  
Physico Chemical ◽  
Negative Effect

The effectiveness of three different extractants soil mixtures—HCl, HCl + H2S04, and DTPA-TEA, in order to determine Si from soil and the forms of Silicon as influenced by different parent materials under acidic medium. Seven forms of Silicon; namely water soluble, specifically adsorbed, oxides bound, organic matter bound, exchangeable, residual, total viz sequential fractionation. Extractable Si value established in this study was (50.0 mg kg-1), indicating negative effect on plant physiology. The physico-chemical properties decreased significantly with increase in soil depth vs soil parent materials. In addition, the forms of Si in the parent materials decreased in the pattern RES, bound residual fractions > EXC, soluble & exchangeable fractions > OM, organic matter fraction. Among the properties the silt fraction, pH & OM significantly and positively correlated with the forms of silicon, with negative correlation vs clay which maybe due to silicon adsorption by clayey fraction of the soil (redox). Therefore the soil maybe be maintained and conserved for farming activities.

scholarly journals Water Birds as Indicators of Ecological Conditions in a Ramsar Wetland (Sebkhet Bazer, East of Algeria)

2021 ◽  
Author(s):  
Sabrina Djerboua ◽  
Sofia Djerdali ◽  
José Guerrero-Casado ◽  
Abdelkrim Si Bachir ◽  
Ali Guendouz
Keyword(s):  
Water Body ◽  
Linear Models ◽  
Abiotic Factors ◽  
Bird Community ◽  
Ecological Indicator ◽  
Bird Abundance ◽  
Seasonal Differences ◽  
Water Bird ◽  
Physico Chemical ◽  
Water Birds

Background: Wetlands are the highly complex ecosystems due to various interactions between the components, where, the most iconic of ecological changes are the water birds. The current study was aimed to examine the interactions between the water birds diversity, abundance and the abiotic factors in Sebkhet Bazer. Methods: The investigation was conducted between March 2013 and December 2014 in Sebkhet Bazer (Sétif, Algeria, 36°05'N and 5°45'E), by monitoring water birds abundance (grouped into 4: Anatidae, Rallidae, Phoenicopteridae and Shorebirds) and measuring the physico-chemical water parameters (depth, temperature, pH, salinity and vegetation cover). All statistical analysis was performed using the InfoStat software (2017), it was carried out in two steps, by testing of fixed linear models; first of the seasonal differences in water body variables and second of the seasonal differences in bird abundance for the 4 water bird groups. Result: The results showed that the physico-chemical parameters of water varied considerably from season to season. The four groups of birds reached their lowest abundance in summer, with Rallidae and Phonicopteridae being more abundant in spring, Anatidae in winter and Shorebirds in autumn, suggesting that this variation is attributed to changes in water body characteristics between the four seasons. Therefore, the abundance of the different water bird group could be used as an ecological indicator of this wetland’s characteristics. If these features are altered by climate change, the water bird community would be also affected.

scholarly journals Is it safe to nest near bold neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nest

2016 ◽  
Author(s):  
Marie-Andrée Giroux ◽  
Myriam Trottier-Paquet ◽  
Joël Bêty ◽  
Vincent Lamarre ◽  
Nicolas Lecomte
Keyword(s):  
Predation Risk ◽  
Spatial Patterns ◽  
Bird Species ◽  
Artificial Nests ◽  
Species Of Conservation Concern ◽  
Composition And Structure ◽  
Negative Effect ◽  
Conservation Concern ◽  
Golden Plover ◽  
Mobbing Behaviour

Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, and nesting in association with protective species. Plovers actively defend their territory by displaying early warning and aggressive/mobbing behaviour, potentially benefiting the neighbouring nests by decreasing their predation risk. To test for the existence of such a protective effect, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests increases and decreases with the distance to and the density of plover nests, respectively. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200 and 500 m from seven of those plover nests. Surprisingly, we showed that predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represent a key step to better understand the importance of these species of conservation concern in tundra food webs.

scholarly journals Nest Survival Patterns in Willow Ptarmigan: Influence of Time, Nesting Stage, and Female Characteristics

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 377-388 ◽  
Author(s):  
Scott Wilson ◽  
Kathy Martin ◽  
Susan J. Hannon
Keyword(s):  
British Columbia ◽  
Annual Variation ◽  
Nest Survival ◽  
Bird Species ◽  
Ecological Factors ◽  
Individual Characteristics ◽  
Willow Ptarmigan ◽  
Female Age ◽  
Daily Nest Survival ◽  
Survival Patterns

Abstract Nest predation is the most important factor limiting reproductive success of Willow Ptarmigan (Lagopus lagopus), as it is for many bird species. Using program MARK, we examined patterns of daily nest survival in two widely separated populations of Willow Ptarmigan in Manitoba and British Columbia, Canada, by examining variation among years, over the course of the breeding season or in relation to the age of the nest, or age and condition of the female. At La Pérouse Bay, Manitoba, daily nest survival increased linearly throughout the season, with moderate annual variation. Nests also had higher daily survival during laying and late in incubation, and lower survival early in incubation. At Chilkat Pass, British Columbia, daily nest survival varied strongly by year and nests had higher survival early and late in the season, but survival was not affected by the age of the nest. At both sites, but especially at Chilkat Pass, periods of lower nest survival tended to coincide with peak breeding periods, suggesting predators may adjust their search effort based on the likelihood of locating nests. Neither female age nor condition were included in the best models. Thus, in both ptarmigan populations, nest survival patterns appeared to be influenced more by ecological factors than by individual characteristics of breeding females. The extent of annual variation and seasonal patterns may have differed between sites due to the different predator and alternative prey communities.

scholarly journals Integrating behaviour and ecology into global biodiversity conservation strategies

2019 ◽  
Vol 374 (1781) ◽  
pp. 20190012 ◽  
Author(s):  
Joseph A. Tobias ◽  
Alex L. Pigot
Keyword(s):  
Extinction Risk ◽  
Spatial Scales ◽  
Bird Species ◽  
Ecological Factors ◽  
Population Pressure ◽  
Conservation Strategies ◽  
Conservation Practice ◽  
Latent Extinction ◽  
Conservation Assessments ◽  
And Migration

Insights into animal behaviour play an increasingly central role in species-focused conservation practice. However, progress towards incorporating behaviour into regional or global conservation strategies has been more limited, not least because standardized datasets of behavioural traits are generally lacking at wider taxonomic or spatial scales. Here we make use of the recent expansion of global datasets for birds to assess the prospects for including behavioural traits in systematic conservation priority-setting and monitoring programmes. Using International Union for Conservation of Nature Red List classifications for more than 9500 bird species, we show that the incidence of threat can vary substantially across different behavioural categories, and that some types of behaviour—including particular foraging, mating and migration strategies—are significantly more threatened than others. The link between behavioural traits and extinction risk is partly driven by correlations with well-established geographical and ecological factors (e.g. range size, body mass, human population pressure), but our models also reveal that behaviour modifies the effect of these factors, helping to explain broad-scale patterns of extinction risk. Overall, these results suggest that a multi-species approach at the scale of communities, continents and ecosystems can be used to identify and monitor threatened behaviours, and to flag up cases of latent extinction risk, where threatened status may currently be underestimated. Our findings also highlight the importance of comprehensive standardized descriptive data for ecological and behavioural traits, and point the way towards deeper integration of behaviour into quantitative conservation assessments. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.

scholarly journals Avian species–area relationships indicate that towns are not different from natural areas

2018 ◽  
Vol 45 (4) ◽  
pp. 419-424 ◽  
Author(s):  
SIMONE FATTORINI ◽  
GIULIA LIN ◽  
CRISTINA MANTONI
Keyword(s):  
Species Richness ◽  
Urban Areas ◽  
Bird Species ◽  
Avian Species ◽  
Conservation Priorities ◽  
Natural Areas ◽  
Bird Richness ◽  
Negative Effect ◽  
Species Area ◽  
Human Density

SUMMARYUrban areas host many bird species, and urban species richness can be compared with that in natural areas using species–area relationships (SARs). We used a multimodel selection approach to investigate the influence of area, human population, elevation and climatic variables on species richness of breeding birds from 34 towns and 54 nature reserves in Italy. Using the linearized power function, area was identified as the most important correlate of avian species richness in both urban and natural areas. The SARs did not differ significantly between towns and reserves, although human density had a negative effect on bird richness. These findings underline the possible importance of urban areas in biodiversity conservation, but also stress that human density is a factor reducing species richness. However, species richness alone cannot inform conservation priorities because it does not take into account the different conservation values of species.

scholarly journals Habitat Selection by the European Nightjar Caprimulgus europaeus in North-Eastern Poland: Implications for Forest Management

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 291
Author(s):  
Michał Polakowski ◽  
Monika Broniszewska ◽  
Lucyna Kirczuk ◽  
Zbigniew Kasprzykowski
Keyword(s):  
Forest Management ◽  
Habitat Selection ◽  
Management Practices ◽  
Bird Species ◽  
Environmental Parameters ◽  
Timber Harvesting ◽  
Forest Edge ◽  
Negative Effect ◽  
Caprimulgus Europaeus ◽  
Management Recommendations

Research Highlights: Intensive forest management practices generally have a negative effect on biodiversity. However, the creation of new, open habitats as a consequence of timber harvesting within large areas of woodland may be favorable to some bird species. Background and Objectives: Habitat selection of the European Nightjar Caprimulgus europaeus in a coniferous woodland area in northeastern Poland was studied in order to specify management recommendations. Materials and Methods: To define the influence of various environmental parameters on territory occupation, 11 micro- and 3 macrohabitat factors were analyzed. Results: Denser vegetation in the ground layer deterred birds from nesting in clearings with such characteristics. Moreover, Nightjars preferentially inhabited sites adjacent to young stands of trees. Birds preferred plots with a higher number of clearings in the neighborhood, as this enabled them to enlarge their foraging area. Other microhabitat factors (e.g., the type, age and area of clearings), as well as macroscale factors like distances to the forest edge, nearest roads and human settlements, were of no importance. Conclusions: Knowledge of the Nightjar preferences may be useful in working out a compromise between an appropriate level of clear-felling and conservation of other bird species requiring preservation of old tree stands.

Effect of hyperthermia in growing broiler chickens on meat quality

2005 ◽  
Vol 2005 ◽  
pp. 170-170 ◽  
Author(s):  
K. Połtowicz ◽  
E. Sosnówka-Czajka
Keyword(s):  
Meat Quality ◽  
Broiler Chickens ◽  
Growth Period ◽  
Poultry Meat ◽  
Technological Parameters ◽  
Broiler Meat ◽  
Physico Chemical ◽  
Negative Effect ◽  
Chemical Traits ◽  
Induced Changes

During growth period of 6 to 7 weeks, broiler chickens are exposed to different stressors, the effects of which are dependent on the type, duration and intensity of stress that affects the bird. Stress-induced changes in muscular metabolism alter the physico-chemical traits of meat, thus affecting its quality (Ali et al., 1999). The negative effect of ante-mortem thermal stress on the quality of broiler meat has been the object of many studies and is relatively well documented (Warriss et al., 1999). There is a scarcity of data on whether and to what degree hyperthermia in growing chickens affects the technological parameters of poultry meat. Therefore we carried out an experiment to determine the effect of 5-day heat stress in 4-week-old broiler chickens on their later meat quality.

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