Costa, J Fagundes, I.;Gouveia,C. · wetlands, with high bird densities are most important for...

Costa, J[1], Rochinha, CA[2]; Costa, L. [1]; Infante, S.[3]; Fagundes, I. [1]; Veríssimo, C. [1]

Inter-Institutional CooperationAn overall study of 3 years started in 2003

thanks to protocols between 2 NGO’s (SPEA

and Quercus), the Governamental

Conservation Institute (ICNB) and two

Electrical Companies: REN -. Very High

Tension Distribution (>110 kV) and EDP

Distribuição – Medium and High Tension

Distribution (1-110 kV)

As a result of this cooperation, there were

established internal norms for the study

and application of mitigation measures

both for REN (2005), EDP Distribuição

(2010), and public guidelines for the study

and mitigation of power lines impact (ICN,

2005).

Later, this cooperation has been shaped into

a Technical Commission for Birds and

Power Lines Surveillance (CTALEA), with

the presence of EDP Distribuição , ICNB,

SPEA and Quercus, which has a consultive

role for projects and works with Medium and

High Voltage

Projects in inland Portugal, Azores and Madeira islandsThe average calculated mortality in

continental Portugal is 3.27 birds/km/year

by collision and 0.17 birds/pylon/year

through electrocution. The total number of

deaths counted in the impact study being

above two thousand birds, for 1109 km of

Medium and High Tension electrical lines

and 7171 pylons prospection.

In Madeira Island, SPEA is evaluating the

collision impact for three sensitive and

globally threatened species, the Eurasian

Woodcock Scolopax rusticola, The Madeira

Storm-petrel Oceanodroma castro and the

Bulwer's Petrel, Bulweria bulwerii.

In the Azores, we are evaluating

electrocution impact, specially on the

Buzzard, Buteo buteo, being the maximum

observed mortality about 0,26 birds/pylon/yr,

in Santa Maria Island.

Main species affected

The most frequently species found is the

white stork, Ciconia ciconia mainly victim to

electrocution around nesting sites, but also

to collision.

While Passerines are mainly affected by

collision, birds of prey account for 40% of

total electrocutions: the Common Buzzard

(Buteo buteo), reaches the highest mortality

found for a single species. Other common

species found are the Common Kestrel,

Falco tinnunculus, the Short-toed Eagle,

Circaetus gallicus, and the Northern

Goshawk, Accipiter gentilis

Costa, J (1), Infante, S. (2); Rochinha, C.A. (3) ; Veríssimo, C. (1), Fagundes, I.;Gouveia,C. (1),

Habitat and SeasonDifferences between bird collision and

electrocution are apparent in the

analysis by habitat type: coastal

wetlands, with high bird densities are

most important for collision whereas

agricultural patchy land together with

dry cereal fields (pseudo-steppe)

accounts for most deaths by

electrocution.

Mortality is higher in the Autumn

migratory season, both for collision

and electrocution, being lowest in

Winter.

Line and pylon configurationMortality depends also on the pylon and line

configuration. cross-arms in triangular

configuration (angle support) for 15 kV is the

most dangerous for electrocution (3.29

ind./pylon/yr), followed by triangular

configuration (alignment), upper horizontal

disconnectors, vertical disconnectors,

horizontal configuration, and finally delta

configuration (N=5869).

For collision, 3-level lines (Delta

configuration) cause more deaths than 2-

level lines (triangular configuration) (4.2

ind./km per yr vs 2.6 ind./km per yr).

Mitigation and Monitoring

Until now, 243,6 km of medium and

high voltage lines have been subject

to mitigation measures, either for

Collision or Electrocution, in

continental Portugal. There were

employed different kinds of mitigation

devices and they are being monitored

to evaluate their efficiency

Correction Measures Efficiency

The conclusions, shown in the tables below,

are still preliminary for it was not applied a

statistical analysis, due to small sample-sizes,

in some categories. The study is in course and

will be continued. The results of the monitoring

project are being integrated in the Official

guidelines for mitigation of power line impacts

and in the Electrical Company internal Norm.

Some common power line bird mortality mitigation devices:Anti-electrocution

High: 70%-93% reduction in

triangular configuration

Tension clamp Cover

and pin insulator Cover

not evaluated

Avoidance of nesting and

perching

Anti-collision

under study

FBF rotator type

FBF ribbon type

under studyBFD Double spiral red &

white

Low: 4-27% in Delta and

triangular lines

Low: 33 % in triangular lines

BFD simple spiral grey

color

BFD simple spiral red &

white

Triangular configuration

Horizontal disconnector

Vertical disconnectors with

tappings

Delta Configuration

BFD-Bird Flight Diverter; FBF-.Firefly Bird Flapper

Pseudo-steppe Scrubland Agricultural Land Inland Waters

(1)SPEA (2)EDP D (3)Quercus

Threatened species

However, the main concern goes to the

threatened species. rare or endangered

populations such as the Great Bustard,

Otis tarda, The Little Bustard,Tetrax tetrax

die by coliding with power lines. The

spanish imperial eagle, Aquila adalberti,

Golden Eagle, Aquila chrysaetus the

Bonelli’s Eagle, Aquila fasciatus, the Red

Kite, Milvus milvus and the Osprey,

Pandion haliaetus eagles are especially

vulnerable to electrocution in power lines,

and others, such as the Roller, Coracias

garrulus, or the Griffon, Gyps fulvus die

from both causes.

Electrocution (ind./pylon/yr) Collision (ind./km/yr)

Azores Is.

Madeira Is.

Portugal