A large-scale experiment demonstrates that line marking reduces power line collision mortality for large terrestrial birds, but not bustards, in the Karoo, South Africa

The Condor ◽  
2021 ◽  
Vol 123 (1) ◽  
Author(s):  
Jessica M Shaw ◽  
Tim A Reid ◽  
Bradley K Gibbons ◽  
Matt Pretorius ◽  
Andrew R Jenkins ◽  
...  
Keyword(s):  
South Africa ◽  
Large Scale ◽  
Bird Species ◽  
Population Level ◽  
Power Line ◽  
Power Lines ◽  
Bird Flight ◽  
Species Of Conservation Concern ◽  
Scale Experiment ◽  
Set Up

Abstract Line markers are widely used to mitigate bird collisions with power lines, but few studies have robustly tested their efficacy. Power line collisions are an escalating problem for several threatened bird species endemic to southern Africa, so it is critical to know whether or not marking works to adequately manage this problem. Over 8 yr, a large-scale experiment was set up on 72 of 117 km of monitored transmission power lines in the eastern Karoo, South Africa, to assess whether line markers reduce bird collision mortality, particularly for Blue Cranes (Grus paradisea) and Ludwig’s Bustards (Neotis ludwigii). We tested the 2 marking devices commonly used in South Africa: bird flappers and static bird flight diverters. Using a before-after-control-impact design, we show that line marking reduced collision rates for Blue Cranes by 92% (95% confidence interval [CI]: 77–97%) and all large birds by 51% (95% CI: 23–68%), but had no effect on bustards. Both marker types appeared similarly effective. Given that monitoring at this site also confirmed high levels of mortality of a range of species of conservation concern, we recommend that marking be widely installed on new power lines. However, other options need to be explored urgently to reduce collision mortality of bustards. Five bustard species were in the top 10 list of most frequently found carcasses, and high collision rates of Ludwig’s Bustards (0.68 birds km–1 yr–1 uncorrected for survey biases) add to wider concerns about population-level effects for this range-restricted and Endangered species.

scholarly journals Monitoring of effectiveness of bird flight diverters in preventing bird mortality from powerline collisions in Slovakia

2019 ◽  
Vol 13 (1) ◽  
pp. 45-59
Author(s):  
Marek Gális ◽  
Michal Ševčík
Keyword(s):  
Bird Species ◽  
Power Line ◽  
Power Lines ◽  
Flight Distance ◽  
Bird Flight ◽  
Before And After ◽  
Bird Mortality ◽  
Positive Effect

Abstract Flight observations and carcass searches were carried out along distribution power lines in Slovakia. 77 km of 22 kV and 110 kV lines were marked on a total of 108 sections to evaluate the effectiveness of three types of bird flight diverters (FireFly Bird Diverter, RIBE Bird Flight Diverter and SWAN-FLIGHT Diverter) designed to increase power line visibility. Numbers of carcasses were compared before and after installation of the devices and reaction distances on marked power lines were surveyed. We observed a 93.5% reduction (93 vs. 6) in the number of fatalities under the marked power lines after line marking (06/2016–06/2019) compared to the period before installation (12/2014–02/2016). 2,296 flight reactions were observed and an estimated total of 41,885 individuals (57 bird species belonging to 13 orders) were recorded with their reactions to marked lines in the period 06/2016–06/2019. After installation of bird diverters, there was a low proportion of flight distance observations at the closest distance, i.e. up to 5 m, indicating that birds reacted further away from marked lines. Although we lack flight observations for the period before the installation of diverters, the reactions of birds at greater distances and reduced number of bird victims under marked lines indicate that all tested diverters have a positive effect on reducing the number of avian collisions with power lines.

scholarly journals Power line routing and configuration as major drivers of collision risk in two bustard species

Oryx ◽  
2020 ◽  
pp. 1-10 ◽  
Author(s):  
Ana Teresa Marques ◽  
Ricardo C. Martins ◽  
João Paulo Silva ◽  
Jorge M. Palmeirim ◽  
Francisco Moreira
Keyword(s):  
Abiotic Factors ◽  
Bird Species ◽  
Power Line ◽  
Power Lines ◽  
Mitigation Measures ◽  
Suitable Habitat ◽  
Collision Risk ◽  
Great Bustard ◽  
Line Configuration ◽  
Tetrax Tetrax

Abstract Collision with power lines is a major cause of mortality for many bird species. Understanding the biotic and abiotic factors that increase collision risk is therefore important for implementing mitigation measures to minimize mortality, such as power line rerouting or wire marking. Here, we used collision events registered during 2003–2015 along 280 km of transmission power lines in southern Portugal to analyse spatio-temporal patterns and collision risk factors in two sympatric, threatened, and collision-prone species: the great bustard Otis tarda and the little bustard Tetrax tetrax. The occurrence of collisions was not uniform across space and time, and variations could be explained by the species' ecological requirements, distribution patterns and behaviour. Although both species fly considerable distances between areas of suitable habitat, collisions were far more likely in power line sections with > 20% (for the little bustard) or > 50% (for the great bustard) of open farmland habitat in the surroundings. Power line configuration was also important: taller pylons and those with a higher number of wire levels posed a higher risk for both species. Wire marking had a small but significant effect for the little bustard, reducing collisions risk. There was, however, no similar effect for the great bustard, possibly a result of limited data. Mitigation measures should be implemented to prevent bustard collisions, including adequate route planning, ideally avoiding areas with > 20% of open habitat. Line configuration and wire marking are particularly important where such localities cannot be avoided and power lines cross areas with a high proportion of bustard habitat, including outside protected areas.

scholarly journals Modelling the risk of collision with power lines in Bonelli’s Eagle Hieraaetus fasciatus and its conservation implications

2010 ◽  
Vol 20 (3) ◽  
pp. 279-294 ◽  
Author(s):  
ÀLEX ROLLAN ◽  
JOAN REAL ◽  
RAFEL BOSCH ◽  
ALBERT TINTÓ ◽  
ANTONIO HERNÁNDEZ-MATÍAS
Keyword(s):  
Urban Areas ◽  
Spatial Scales ◽  
Population Level ◽  
Power Line ◽  
Power Lines ◽  
Turnover Rates ◽  
Distribution Lines ◽  
Bonelli’S Eagle ◽  
Hieraaetus Fasciatus ◽  
Earth Wires

SummaryPower line casualties are considered one of the main causes of mortality in the endangered Bonelli’s Eagle Hieraaetus fasciatus, although little is known about factors involved in collisions with wires and their consequences at population level. We studied 18 radio-tracked individuals to determine the risk of collision with power lines at two spatial scales (flight height and span crossings). Through logistic regression modelling we found that the risk of collision was mainly determined by eagles’ home range use, being reduced in kernel 80%, kernel 95% and MCP respectively to 0.421, 0.114 and 0.032 times in comparison to risk associated to the 50% kernel area. In addition, the risk of collision increased in open habitats (around 1.5 times higher than in forested habitats) far from urban areas (2.345 times higher than near urban areas) that were good for hunting, and in cliff areas used for breeding and roosting, where eagles fly at a lower height (the probability of eagles flying at a low height was 1.470 times higher than in forested habitats). A significant positive correlation was found between territorial turnover rates and the risk ascribed to transmission lines with earth wires in 15 breeding territories. Moreover, this correlation had a higher significance for the 50% kernel area when transmission without earth wires and double circuit distribution lines were added, although no correlations were encountered for distribution lines. These results suggested that power line collisions might be more important than previously reported as a cause of mortality for the species and thus conservation actions should be applied in order to minimise their effects on population dynamics. Predictive models may be a useful tool in careful planning of new power line routes and the wire-marking of the existing ones. Kernel areas should be used rather than fixed radii given that distances from nests may not adequately match the risk of collision.

scholarly journals Effects of Power Lines on Area Use and Behaviour of Semi-Domestic Reindeer in Enclosures

2009 ◽  
Vol 2009 ◽  
pp. 1-14 ◽  
Author(s):  
K. Flydal ◽  
L. Korslund ◽  
E. Reimers ◽  
F. Johansen ◽  
J. E. Colman
Keyword(s):  
Large Scale ◽  
Power Line ◽  
Power Lines ◽  
Disturbing Factor ◽  
Reindeer Husbandry ◽  
Stable Level ◽  
Area Use ◽  
Line Construction ◽  
A Minor ◽  
Wild Reindeer

We conducted large-scale, replicated experiments to test the effects of two parallel power lines on area use, behaviour, and activity of semidomestic reindeer in enclosures. Yearling female reindeer were released into four50×400 m enclosures; two treatment enclosures with power lines and two control enclosures. Reindeer from two herds, one from Kautokeino (domestic tame) and one from Vågå, (domestic wild) were tested separately and compared. Individual location within the enclosures was not affected by the power lines. Effects on restless behaviour were ambiguous, with slightly more restless behaviour in the treatment enclosures for the domestic tame reindeer, while the domestic wild reindeer maintained a stable level in the treatment enclosures, increasing with time in the control enclosures. Activity changes were slightly more common among animals within treatment enclosures for both herds, with no indication of habituation during the experiment. The domestic wild reindeer had more than three times the amount of restless behaviour than the domestic tame reindeer. Our study indicates that for reindeer in enclosures, the disturbance from a power line construction is negligible. This suggests that power lines are a minor disturbing factor compared to human handling when using fenced in areas like grazing gardens in reindeer husbandry.

scholarly journals The Value of Utilizing the Complete Temporal Distribution of Phenological Data

2019 ◽  
Vol 3 ◽  
Author(s):  
Maria Hällfors ◽  
Laura Antão ◽  
Malcolm Itter ◽  
Aleksi Lehikoinen ◽  
Tanja Lindholm ◽  
...  
Keyword(s):  
Large Scale ◽  
Bird Species ◽  
Temporal Distribution ◽  
Population Level ◽  
Holistic Approach ◽  
Rate Of Change ◽  
Large Variability ◽  
Phenological Data ◽  
Bird Breeding ◽  
Underlying Mechanisms

Numerous studies over the past decades have shown that species phenologies are shifting. Behind the large-scale patterns of shifting phenologies lies, however, large variability across species and space in terms of both the sign of the shifts (advance or delay) and their magnitude (rate of change). The shifts in the timing of seasonal events are usually studied by measuring change in one part of the phenological distribution over the season, such as the mean or first appearance of the event. This, however, gives us a mere glimpse of how (part of) a population is changing, thus limiting our ability to understand the underlying mechanisms. We demonstrate the benefits of taking a holistic approach to describing phenological change by considering shifts in the complete phenological distribution and interrelationships within it. As a case study, we make use of a database on bird chick banding events to understand the shifts in breeding phenology for 74 bird species across 43 years and 4 bioclimatic zones distributed across Finland. We find that bird breeding is stacking up towards earlier and more compressed peak periods. The majority of change can be attributed to a faster advance of the tail of the distribution, alongside minor advancement of the beginning of the season. We conclude that the observed shifts potentially intensify intraspecific competition by increasing the temporal co-occurrence of broods across large geographical areas. Nevertheless, these patterns would likely have not been recognized through summarizing the data by species mean dates alone. We therefore urge scientists and data managers to compile and utilize phenological data at higher resolution, retaining the original detail. This will allow us to capture multiple modes of population-level change, thereby providing deeper insights into how species are responding to ongoing climate warming.

scholarly journals Methodology of risk assessment for electricity distribution lines in Slovakia with regard to potential bird mortality due to collisions with power lines

2019 ◽  
Vol 13 (1) ◽  
pp. 61-73
Author(s):  
Ján Šmídt ◽  
Ervín Hapl ◽  
Marek Gális
Keyword(s):  
Bird Community ◽  
Cost Effective ◽  
Power Line ◽  
Power Lines ◽  
Mitigation Measures ◽  
Migration Routes ◽  
Bird Flight ◽  
Line System ◽  
Bird Mortality ◽  
Landscape Information

Abstract Power lines represent an important and increasing worldwide cause of avian mortality due to collisions involving flying birds. One positive and very important fact is that only some parts of potentially dangerous lines are responsible for the majority of killed birds. These sections need to be identified and treated with proper mitigation measures. In this article we present a specially-prepared methodology aimed at classifying power lines according to the risk they present. The identification of power lines with the highest risk of possible bird collision requires easily-accessed biological, technical and landscape information. In addition to analyses of these main inputs, our methodology also evaluates the influence of power line orientation relative to the important migration routes of birds, the effect of nearby tree growth higher than the evaluated power lines, and the complexity of landscape relief. Based on these three additional inputs, it is possible to produce a digitalized map showing with one-meter accuracy the location of power line sections with the high/middle/low mortality risk due to collision for any existing or newly-planned grid. Sections with highest risk should be considered as priority for the implementation of mitigation measures including e.g. installation of bird flight diverters. Our methodology was prepared for 22 kV and 110 kV distribution power lines in Slovakia. It is flexible enough to be applied equally to any geographic conditions and/or bird community, different voltage levels and construction designs of power lines. Our methodology can be applied by ornithologists, nature conservancy organization and power line system operators to implement environmental and cost-effective mitigation measures.

Steam Condensation Experiments by the MISTRA Facility for Field Containment Code Validation

2002 ◽  
Author(s):  
M. Caron-Charles ◽  
J. J. Quillico ◽  
J. Brinster
Keyword(s):  
Large Scale ◽  
Short Description ◽  
Steam Condensation ◽  
Transfer Coefficients ◽  
Test Program ◽  
Heat Transfer Coefficients ◽  
Mass And Heat Transfer ◽  
Scale Experiment ◽  
Set Up ◽  
Dimensionless Correlations

The MISTRA facility is a large scale experiment, designed for the validation of thermal-hydraulics multi-D codes. A short description of the facility, the set up of the instrumentation and the test program are presented. Then, experimental results, studying axisymmetric flows of steam injected in the containment and condensed on temperature regulated walls are detailed. Experimental evaluation of the mass and heat transfer coefficients is proposed, then they are compared with the prediction of usual models for condensation, such as Tagami Uchida (0D codes) and the dimensionless correlations (multi-D codes).

History of South Africa’s Bantustans

2017 ◽  
Author(s):  
Laura Phillips
Keyword(s):  
South Africa ◽  
Middle Class ◽  
Ethnic Group ◽  
Large Scale ◽  
Black Middle Class ◽  
South Africans ◽  
Democratic State ◽  
Black South Africans ◽  
History Of ◽  
Set Up

With the passing of the Bantu Authorities Act in 1951, the apartheid set in motion the creation of ten bantustans, one of South Africa’s most infamous projects of racial ordering. Also known as “homelands” in official parlance, the bantustans were set up in an attempt to legitimize the apartheid project and to deprive black South Africans of their citizenship by creating ten parallel “countries”, corresponding to state designated ethnic group. The bantustan project was controversial and developed slowly, first by consolidating “native” reserve land and later by giving these territories increasing power for self-governance. By the 1980s there were four “independent” bantustans (Transkei, Ciskei, Venda, and Bophuthatswana) and six “self-governing” ones (Lebowa, Gazankulu, KwaNdebele, Qwaqwa, KaNgwane, and KwaZulu). While a few bantustan leaders worked with the anti-apartheid liberation movements, the bantustans were largely rejected as political frauds governed by illegitimately installed chiefs. They acted as dumping grounds for surplus cheap African labor and allowed the apartheid government to justify large-scale forced removals from “white” farmlands and cities. But the bantustans were also incubators of a black middle class and bureaucratic elite. Despite the formal dissolution of the bantustans in 1994 and their reincorporation into a unitary democratic state, the rule of chiefs and the growth of this black middle class have a deep-rooted legacy in the post-1994 era. As several contemporary commentators have noted, South Africa has witnessed the “bantustan-ificaton” of the post-apartheid landscape.

scholarly journals Simultaneous immobilization of arsenic and cadmium in paddy soil by Fe-Mn binary oxide

Elem Sci Anth ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Longyong Lin ◽  
Junchun Li ◽  
Xiao Yang ◽  
Xiulan Yan ◽  
Tongtong Feng ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Large Scale ◽  
Root Surface ◽  
High Accumulation ◽  
Rhizosphere Soils ◽  
Binary Oxides ◽  
Theory To Practice ◽  
Scale Experiment ◽  
Set Up ◽  
Simultaneous Immobilization

Paddy soil in south China has long been haunted by the co-contamination of arsenic (As) and cadmium (Cd), resulting in the relatively high accumulation of As and Cd in rice, which puts humanity into a food safety dilemma. Therefore, it is paramount to restrain the migration of contaminants from soil to rice grains to cushion their impact on human health. However, the opposite biogeochemical behaviors of As and Cd in paddy soils under flooding condition make it a great challenge to simultaneously immobilize both As and Cd, particularly for the large-scale remediation. In this work, lime, Fe2O3, and Fe-Mn binary oxides (FM) were performed for immobilizing As and Cd in paddy soil at a field-scale experiment, and their associated mechanisms were discussed. Results showed that 0.10 wt% of Lime reduced Cd in grain (36.68%), 0.60 wt% of Fe2O3 decreased the accumulation of As and Cd (28.32% and 26.91%, respectively), and 0.60 wt% of FM significantly decreased As and Cd (42.42% and 36.49%, respectively). Analytical results of As speciation in rhizosphere soils demonstrated that FM played a dual role in oxidation and adsorption toward As immobilization. The DGT-measured As and Cd concentrations in rhizosphere soils showed that 0.60 wt% of FM significantly reduced the bioavailability of As and Cd in the paddy soil by 65.63% and 52.98%, respectively. Moreover, 0.60 wt% of FM promoted the formation of Fe/Mn-plaque on root surface, which significantly enhanced the adsorption of As and Cd upon Fe/Mn-plaque (44.06% and 32.14%, respectively) and further inhibited the uptake of As and Cd by rice. Hence, the mechanism for As and Cd immobilization by FM can be summarized: (1) oxidation of As(III) to As(V) and transformation and immobilization of As and Cd in rhizosphere soil and (2) promotion of Fe/Mn-plaque formation on root surface to retard the uptake of As and Cd by rice. These efforts attempt to set up a theory-to-practice solution for remediating As and Cd co-contamination in paddy soil.

Platelet Anti-Aggregating Activity and Tolerance of Clopidogrel in Atherosclerotic Patients

1996 ◽  
Vol 76 (06) ◽  
pp. 0939-0943 ◽  
Author(s):  
B Boneu ◽  
G Destelle ◽  
Keyword(s):  
Platelet Aggregation ◽  
Large Scale ◽  
Bleeding Time ◽  
Antithrombotic Activity ◽  
Ambulatory Patients ◽  
Patients At Risk ◽  
Set Up ◽  
Ischemic Events ◽  
Large Scale Clinical Trial ◽  
Selection Of

SummaryThe anti-aggregating activity of five rising doses of clopidogrel has been compared to that of ticlopidine in atherosclerotic patients. The aim of this study was to determine the dose of clopidogrel which should be tested in a large scale clinical trial of secondary prevention of ischemic events in patients suffering from vascular manifestations of atherosclerosis [CAPRIE (Clopidogrel vs Aspirin in Patients at Risk of Ischemic Events) trial]. A multicenter study involving 9 haematological laboratories and 29 clinical centers was set up. One hundred and fifty ambulatory patients were randomized into one of the seven following groups: clopidogrel at doses of 10, 25, 50,75 or 100 mg OD, ticlopidine 250 mg BID or placebo. ADP and collagen-induced platelet aggregation tests were performed before starting treatment and after 7 and 28 days. Bleeding time was performed on days 0 and 28. Patients were seen on days 0, 7 and 28 to check the clinical and biological tolerability of the treatment. Clopidogrel exerted a dose-related inhibition of ADP-induced platelet aggregation and bleeding time prolongation. In the presence of ADP (5 \lM) this inhibition ranged between 29% and 44% in comparison to pretreatment values. The bleeding times were prolonged by 1.5 to 1.7 times. These effects were non significantly different from those produced by ticlopidine. The clinical tolerability was good or fair in 97.5% of the patients. No haematological adverse events were recorded. These results allowed the selection of 75 mg once a day to evaluate and compare the antithrombotic activity of clopidogrel to that of aspirin in the CAPRIE trial.

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