Donna's death highlights power line dangers

09-03-2005

The longest continuous satellite tracking of an individual bird came to an end on March 5, when a White Stork Ciconia ciconia known as Donna was electrocuted by power lines. First tagged in 1999 by the Storks Without Borders project run by Natuurpunt (part of Birdlife in Belgium), Donna was tracked for 2,033 days.

Donna left Seville in Southern Spain on the 11 February 2005, stopped off near Madrid for ten days, and reached Calvados in Northern France (the site of her unsuccessful 2004 breeding attempt) on March 4. The next day local stork specialist Alain Chartier found her dead under power lines near the estuary of the river Seine. She was in prime breeding condition.

According to Wim Van den Bossche, project leader of Storks Without Borders, electrocution and collision with power lines are the main known causes of mortality in storks. Research along the intensively-used stork migration route in Israel revealed that 59 percent of dead storks had hit wires.

BirdLife Belgium

Donna as a chick at her nest (top bird), with one of her parents
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"No other bird has been tracked on a daily basis for such a long period. Donna provided us with a mass of unique scientific data." —Wim Van den Bossche, Storks Without Borders

Electrocution and collision have been implicated in decline, or range abandonment, among other large birds, including Great Bustards Otis tarda and Eagle Owls Bubo bubo. At least 30 percent of newly fledged Spanish Imperial Eagles Aquila adalberti are electrocuted each year, an unsustainable level of mortality for a bird with a tiny population (fewer than 200 pairs) which takes 4-5 years to reach breeding maturity.

When power lines around Spain’s Donana National Park were buried, survival rates among radio-tagged Spanish Imperial Eagles in the first six months of their lives rose from 17.6 percent to 80 percent.

"Bird-friendly" alterations to power lines can reduce mortality among storks, eagles and other large birds. Plastic caps and tubes can be fitted quickly and cheaply to existing pylons, poles and cables to prevent or reduce electrocution, and guidelines are available to ensure that new power lines present the minimum risk to birds.