Modelling key factors of nightjar avoidance behavior at

Dr. Andreas Traxler, BIOME Austria

Modelling key factors of nightjar avoidance behavior at wind farms across Europe

image © Richter

28.08.2019Dr. Andreas Traxler: Modelling key factors of nightjar avoidance behavior at wind farms across Europe

Species-specific safety rangerecommendations for windfarms

Safety range around BREEDING SITES

Verification range

Regularly frequented flight paths


Safety range recommendations encountered in Germany & Austria

„Helgoland Paper“ 2014: WORKING GROUP OF GERMAN STATE BIRD CONSERVANCIES [LAG VSW]

500 m to the nest (precautionary recommendations)

LANGEMACH & DÜRR 2019: „Information on wind-energy impacts on birds“

200 – 250 m (avoidance radius)

Case example: Nightjar safety ranges

image © Dürr


Nightjar survey and impact assessment

From where is Safety range measured?

•breeding site

• song territory, churring sites

•homerange


One-minute Nightjar excursion

• Nocturnal and hidden activity

• Flying insect hunter moths, beetles, flies,…

• Ground breeder no nest-building

• Various habitat types oceanic to steppe-climate

• General knowledge gaps

• Hard to investigate populations and reproduction ratesMain references:Schlegel 1969, Wichmann 2004, Brünner et al. 2008


Nightjar survey handicaps


One-minute Nightjar excursion

May & Augustextended feedinghabitat

June, July (& August)reduced activity range(1st & 2nd brood)

SeptemberAutumn migration toSouthern Africa

in accordance with SHARPS 2013


1. Acoustical mapping of churring sites no localisation of breeding sites

2. Tracking approaches (bird catching required)

Advantage: breeding success

a. Standard devices: UHF / VHF radio-tags

Nightjar survey principles

b. Next step: micro GPS-tagssatellite trackingfrequent signal intervals


Collision mortality

1x 2001 in Spain LANGGEMACH & DÜRR 2019 (small turbines)

1x 2015 in Bulgaria (migrating bird)

no collision reports during breeding season with modern turbines

Disturbance effects

- displacement of churring males INCONSISTENT RESULTS!

- reduction of breeding success FEW STUDIES (SHEWRING 2019)

Potential wind energy impacts on the Nightjar


Turbine & windfarm designs have changed markedly over the last decades!

Development of windfarm design & impacts

1985: Kenetech KCS 56 - 100KWø 17m, 20m hub

Altamont pass windfarm (USA)

strong barrier effects, collision20m


2005: Enercon E-70 - 2.3MWø 71m, 56m hub

max 54 db

sound pressure at windfarm center250m



2018: Vestas V 136 - 3.45MWø 136m, 149m hub

max 47 db

- 50% sound pressure!

600 - 1000m

less barrier effects



Displacement of habitat utilisation INCONSISTENT RESULTS!

Germany: > 50% displacement of churring males (at windfarm area + 150m)

KAATZ ET AL. 2007, KAATZ ET AL. 2010, KAATZ 2014


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• Construction start: autumn 2006

• 31 turbines in open heathland

• Enercon E-70– 2.3MW

• Hub height: 56m

• Ø 71m

• min turbine distance: 250m

Heidehof WFEastern Germany

250m


Churring males after 6 years

• 100% decrease in WF area

• 30% increase in 150 - 1,000m

Heidehof WFEastern Germany

Mode of windfarm Reports of churring males

windfarm 150 – 1000m

Pre-construction(2006)

10 13

1st year 1 26

5th year 4 26

6th year 0 18

250m

Suboptimal, encircling windfarm design:Small turbines and small min. distances

Significant displacement of song territories





Sweden: No effect, moderate decline (20%) and 60% increase

of churring males within windfarm areas

RYDELL ET AL. 2017


±

-


• Construction start: autumn 2010

• 6 turbines

• Nordex N90 – 2.5MW

• Hub height: 100m

• Ø 90m


Brattön WFMunkedal (Sweden)

780m


Churring males within 6 years ofoperation

• up to 60% increase in WF area

Brattön WFMunkedal (Sweden)

780m

Operation phase Reports of churringmales at windfarm

Pre-construction (2009) 6

4th year 8 – 10

5th year 4 – 5

6th year 7





Sweden: No effect, moderate decline (20%) and 60% increase

of churring males within windfarm areas

RYDELL ET AL. 2017

Wales: Constant breeding success and number of breeding territories

at three modern windfarms

SHEWRING 2019A, 2019B (long-term radio-tagging)


±

-

±


BIOME: CASE STUDY in Kaliakra (Bulgaria) (2019 IN PREP.)

no pre-construction data! (built 2008)


Kaliakra WFKavarna (Bulgaria)

• Operating since 2008

• 35 turbines in steppe-habitat

• 1MW

• Hub height: 69m

• Ø 61m


• BUT: line distance >600m !


Despite poor habitat quality at WF site:

after 11 years of operation

churring males within a 200m distance

flight movements towards

turbines at < 100m distance

Kaliakra WFKavarna (Bulgaria)


Minimum distances to wind turbines

< 60m

< 100m

Radio-tagging results:regular surveillance of hunting flights between turbinesTHERKILDSEN 2017

multiple reports of nesting sites within a 60 m rangeSHEWRING 2019B

churring siteswithin a 100 m range

RYDELL ET AL. 2017, BIOME REPORT IN PREP.


Disturbance model scheme

linear windfarm design

minimised disturbance

encircling windfarm design

Accumulatingmulti-directional effects!


Operating windfarm impacts on nightjarspermanent displacement (churring & nesting)permanent displacemet (churring) displacement at high noise level (churring)precautionary zoneConcentration of displaced individuals

Nightjar disturbance model

Input:

aerial images of wind farms and spatial data from acoustic and telemetric observations

Output:

Spatial pattern of disturbancepotential

600m

200m


Conclusio

200 - 250m (500m) safety range recommendations are based on

dense/noisy windfarm designs

Data from modern windfarms indicates a

100m safety range to be sufficient for churring males!


Conclusio

Displacement effects on flight movements and breeding sites seem to beinsignificant!


Recommendations

Avoid noisy turbine types and dense windfarm designs!

Apply minimised disturbance windfarm designs at critical sites!

Keep a precautionary distance of 100m to churring sites!


Thank you for listening!

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Modelling key factors of nightjar avoidance behavior at