Hill et al. Collision mitigation and avoidance behaviour Migrating birds and offshore wind turbines: How to reduce collisions and avoidance behaviour?

Avitec Research Reinhold Hill, Katrin Hill, Ralf Aumüller, Karin Boos & Sabine Freienstein

Hill et al. Collision mitigation and avoidance behaviour

Projected offshore wind farms in the German EEZ

2003

2009

Hill et al. Collision mitigation and avoidance behaviour

ca. 120 m Ø

Hill et al. Collision mitigation and avoidance behaviour

Photo: K. F. Jachmann

Bird migration at FINO-platforms

• When, where, who and under which conditions?

When: annual and diurnal migration patterns

Where: flight altitudes, heading, regional differences

Who: species spectra, migration intensity, abundances

Which conditions: local weather parameters

Effects of wind turbines on migrating birds ?

Hill et al. Collision mitigation and avoidance behaviour

Methods of detection

Radar systems: vertical & horizontal

Visual observation: Seawatch

Intensity, time of day, flight-

height profiles, phenology

Acoustic systems: Microphone

Species spectra (at night +

limited), phenology

Intensity, heading, flight-height

profiles, (time of night)

(heading), species spectra

Species spectra (at day),

phenology, intensity, time of

day, heading, height

Height profile > 200 m

Hill et al. Collision mitigation and avoidance behaviour

Licht

www.fino-offshore.de

Hill et al. Collision mitigation and avoidance behaviour

Effects I – Risk of collision?

When and under which conditions do

(mass-) collisions take place and

what are the causes?

Hill et al. Collision mitigation and avoidance behaviour

Effects I: casualties of collision

Since 2003 (FINO1):

• 4 mass-collision events with 88-199 casualties

• Predominantly affected: Thrushes

• Risk of collision mainly during night

• The number of casualties blown away by the wind or eaten by gulls is unknown

Photo: F.K. Jachmann

Hill et al. Collision mitigation and avoidance behaviour

Effects I: casualties of collision

Since 2003 (FINO1 and FINO3):

• 1067 dead birds in total found (at 423 helicopter flights)

Hill et al. Collision mitigation and avoidance behaviour

• Collisions at FINO3 are significantly rarer (even without mass collisions

at FINO1)!

Effects I: casualties of collision

Hill et al. Collision mitigation and avoidance behaviour

Ho

url

y s

um

s [

call

s/h

]

1./2.11.2010 CET

Cause I: Collision & region ?

• Mainly Thrushes collide at both platforms

• at FINO3 there are almost no Finshes and Pipits, which

can be found regularly at FINO1

Hill et al. Collision mitigation and avoidance behaviour

Blackbird Redwing Starling Others

Ind

ex

of

ca

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cti

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y p

er

sp

ec

ies

an

d h

ou

r

Blackbird Redwing Starling Others

Ind

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of

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sp

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Cause I: Collision & region ?

Hill et al. Collision mitigation and avoidance behaviour

Cause II: Collision & weather ?

Adverse migration conditions

Upcoming bad weather front

modified after Aumüller et al. 2011

Hill et al. Collision mitigation and avoidance behaviour

Cause II: Collision & weather ? W

ind

ve

loc

ity (

m/s

) W

ind

ve

loc

ity (

m/s

)

Win

d d

irec

tio

n (

°)

Win

d d

irec

tio

n (

°) a

nd

vis

ibil

ity (

km

)

Headwind

Tailwind

Headwind

Tailwind

NE

NE

Hill et al. Collision mitigation and avoidance behaviour

Illumination of the

name and Jacket with

broadbanded

Halogen-Spotlights

Narrowbanded

Spotlights

No illumination

of the name

Stronger phototaxis? Less phototaxis?

Cause III: Collision & lights ?

Hill et al. Collision mitigation and avoidance behaviour

Offshore bird migration

Predisposition:

genetic determination for times of migratory restlessness (species or population specific)

Weather:

Weather conditions affect diurnal and annual migration behaviour, as well as migratory routes.

Result:

There is enormous variability in daily and annual intensities and species composition of migrating birds - within and between years

Non-continuous studies therefore face special difficulties.

Before-after-comparisons are hardly explicable in a causal way.

Hill et al. Collision mitigation and avoidance behaviour

Windfarm „alpha ventus“

N

Hill et al. Collision mitigation and avoidance behaviour

Seawatch

74 Cormorants

10 Brent Geese

6 Greylag Geese

5 Cormorants

5 Curlew Sandpiper

• So far recorded: migration intensity

(Ind./h) and behavioural deviations

• Result: high interannual variabilty,

limited data for avoidance behaviour

• New: standardised methods for

viewing direction :

4 sectors á 90 viewed per hour

• Advantage: differences in species

numbers, -frequencies and heading in

wind farm affected and unaffected

sectors, respectively.

Hill et al. Collision mitigation and avoidance behaviour

Directions of observation

Hill et al. Collision mitigation and avoidance behaviour

Directions of observation

Hill et al. Collision mitigation and avoidance behaviour

Avian diversity differs strongly depending on

observational direction

(ANOVA, F3,60 = 11,84; p < 0.001)

Wind farm affected areas are clearly avoided

by migrating birds

(wind farm affected areas = low shares of diversity

Wind farm un-affected areas = high shares of diversity)

Effects II: avoidance behaviour

Hill et al. Collision mitigation and avoidance behaviour

Taxa-specific avoidance behaviour

Gannet – Morus bassanus

Hill et al. Collision mitigation and avoidance behaviour

Taxa-specific avoidance behaviour

Terns – Sternidae

Hill et al. Collision mitigation and avoidance behaviour

Taxa-specific avoidance behaviour Auks - Alcidae

Hill et al. Collision mitigation and avoidance behaviour

Taxa-specific avoidance behaviour

Passerines – Passeriformes

Hill et al. Collision mitigation and avoidance behaviour

Avoidance behaviour

Abundance (%) per direction in sectors

< 3 km > 3 -10 km

Hill et al. Collision mitigation and avoidance behaviour

• most migrating birds seem to avoid wind farms at

daylight and good visibility – very few collisions are to

be expected

• but we have to be careful during the planning process in

order to prevent dead ends with possible higher collision

rates

• it seems to be possible to calculate detours for the birds

and therefore to get a measure for cumulative effects

Avoidance behaviour

Hill et al. Collision mitigation and avoidance behaviour

• there are still open questions and a lack of

knowledge and therefore we have to collect

more data and improve the methods

• we have to use fewer lights and less light

intensity in order to prevent phototaxis and

collisions

• there is a need to develop lights with

minimized attraction to birds (AVILUX)

• we have to develop an early warning system

in order to shut down the turbines in nights of

mass migration in low altitudes

Conclusions

Hill et al. Collision mitigation and avoidance behaviour Thank you

for your attention and

to all supporting partners !

Hill et al. Collision mitigation and avoidance behaviour

Ongoing research project AVILUX aims to

find “bird friendly“ colours for safety lights

Contact: reinhold.hill@avitec-research.de