Monday, November 26, 2012

BIRD COLLISION DEATHS: POWER LINES

http://www.birdlife.org/community/wp-content/uploads/2011/05/powerlinesbird-MME-Hungary.jpg

Source: Birdlife (c) MME/ BirdLife Hungary, accompanying an article concerning the Budapest Declaration on bird protection and power lines. Adopted by the Conference “Power lines and bird mortality in Europe” (Budapest, Hungary, 13 April, 2011)  

 

In November 2011, two reports - The Review of the Conflict Between Migratory Birds and Electricity Power Grids in the African-Eurasian Region and the Guidelines on How to Avoid or Mitigate the Impact of Electricity Power Grids on Migratory Birds in the African-Eurasian Region were reviewed at a UN wildlife conference in Norway. These were some of their findings:

Power lines constitute one of the major causes of unnatural death for birds both through electrocution and fatal collisions. At end of 2010 there were 70.5 million kilometers of power lines throughout the world, constructed with minimal consideration of their environmental impact. This is expected to increase to 76.2 million kilometers by the end of 2015.

The review shows that in the African-Eurasian region alone, hundreds of thousands of birds die annually from electrocution and tens of millions of birds from collision with power lines. In general, large birds seem to be more affected.

For some large, slow reproducing bird species which migrate across this region, such as pelicans, storks, flamingos, birds of prey, cranes, bustards and owls, the death toll could possibly lead to population declines or local or regional extinction.

A Blue Crane killed after colliding with electricity power grid

In South Africa, for example, 12% of Blue Cranes, South Africa's national bird, and 11-15% of Ludwig's Bustards are dying annually in collisions with a growing number of power lines.

According to the review, hotspots for electrocution are especially found in open habitats lacking natural perches or nesting trees for the birds, such as steppes, deserts and wetlands.

"The international guidelines present a number of appropriate legislative and policy actions and some creative technical measures on how to mitigate and reduce the vast number of unnatural bird mortalities caused by electricity power grids," said CMS Executive Secretary Elizabeth Maruma Mrema.

While the scope of the study was to review the situation across Europe, parts of Asia, the Middle East and Africa, the measures highlighted in the guidelines can be applied globally.

In northern Europe, for example, all low and medium voltage distribution lines have been placed underground in the Netherlands and similar measures are also being carried out in parts of Belgium, the United Kingdom, Denmark, Germany and Norway.

"Our experience from Norway is that there are various measures that can reduce the risks of collision and electrocution, such as the use of underground cables, removal of the top line and route selection, and that they are working," said Erik Solheim, Minister of the Environment and International Development of Norway.

Other less expensive measures include the insulation of dangerous electric parts of the lines, the installation of bird-friendly perching and nesting devices as well as the installation of markers or bird flight diverters in overhead wires.

The relative lack of electrical infrastructure across the African continent to date provides an opportunity to avoid the mistakes made elsewhere when new infrastructure is constructed.’

Source: UNEP news centre

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Source: Green Guide Spain

The Spanish imperial eagle (Aquila adalberti) is a long-lived resident tree-nesting raptor endemic of the Iberian Peninsula. With an estimated population of 250 pairs (National Working Group, unpublished data 2008), it has been considered one of the most endangered raptors in the world

Electrocution on power lines has been reported to be the main known cause of death for the species, accounting for 60% of mortality cases with a strong sex-biased distribution towards female birds.

In late 80's and early 90's, several studies highlighted the risk of electrocution to population persistence of the Spanish imperial eagle  and mitigation measures were instigated accordingly. As a consequence, electrocution rates have changed from accounting for nearly 60% of total mortality events to 39.87%.   

the reduction in electrocution fatalities has been accompanied by a general increase in the population, and demonstrates that at least some large scale conservation problems can be resolved. However, the question remains as to the total cost of fixing the problem, and whether that cost is affordable.

Conservation and the preservation of biodiversity require financial investment from both the public and private sector budget. In our case, nearly €2.6 million have been spent on mitigation of bird electrocution during 1992–2009, which equals an investment of €154,352.94 per year. The Spanish imperial eagle population in Andalucía has increased from 31 to 60 pairs in the same period. Taking into account the high budgets assigned to the construction of new power lines and alternative power sources (e.g. wind farms, solar panel arrays), our results demonstrate that solving bird electrocution is an affordable problem if political interest is shown and financial investment is made.’

Extracts from: Solving Man-Induced Large-Scale Conservation Problems: The Spanish Imperial Eagle and Power Lines by Lopez-Lopez et al. (2011) Source: www.plosone.org

 

Death by electrocution is the primary cause of death of the Bonelli’s Eagle (Aquila fasciata). (Credit: Universidad de Barcelona)

A study published in the American Journal of Wildlife Management  in 2010 was produced by the University of Barcelona's Conservation Biology Group, directed by Joan Real of the Department of Animal Biology. It focused on preventing bird electrocution through the identification and correction of high-risk pylons.

‘In Catalonia, electrocution is the primary cause of death of the Bonelli's Eagle (Aquila fasciata), and across the rest of the Iberian Peninsula it affects particularly large numbers of the endangered Iberian Imperial Eagle (Aquila adalberti) and many other ecologically valuable species.

‘Electrocution occurs when a bird comes into contact with two wires or when it perches on a conductive pylon (for example, a metal structure) and comes into simultaneous contact with a wire. In Catalonia, there are more than 1000 different models of electricity pylons, which pose different levels of threat to birds.’

According to Joan Real, applying correction measures "to only 6% of the most dangerous pylons could reduce bird mortality by up to 70%."

Source: Science Daily

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The golden eagle is one of five "Birds of Prey" now depicted on U.S. postage stamps (2012). Source: Outdoors blog

‘The birds that are most affected by unshielded electrical equipment are raptors such as eagles and hawks, and these raptors tend to seek high perches on which to sit and survey the scene, searching for prey.‘

‘The data are scattered, incomplete, and in some cases old, but one study published in 1995 is suggestive: in a survey of some 4,300 cases of eagle mortality around the United States from 1960 to 1990, electrocution was the second most common cause of death, after accidental trauma and far ahead of gunshot or poisoning. Golden eagles were more susceptible than bald eagles to electrocution, precisely because they favor treeless habitats in which power lines provide the only perches.

Similar conditions obtain in the steppes and deserts of Russia, Central Asia, China, and Africa. The documentation from such places is even scarcer, but a recent German study of a nature reserve on Lake Tengiz, in Kazakhstan, reports that ‘numerous birds, including 200 Kestrels, 48 Steppe Eagles, two Spanish Imperial Eagles, one White-tailed Eagle and one Black Vulture were recorded killed by electrocution along an eleven-kilometer medium voltage overhead power line for the month of October 2000 only.’

Source: ‘Bird on a Wire: The Electrocution of Wild Birds’ by Gregory McNamee on www.advocacy.britannica.com

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Eagles nest on power poles

Eagles and power poles

Two solutions developed by conservationist Morian Nelson to protect eagles from electrocution in the US. See full story here: One More Hero by Allan Gates.

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