Wind turbines offshore of Flamborough (1 Viewer)

[Andy Adcock]

Wouldn't it be possible, to design a safety guard for these turbines such as the ones we have on domestic fans?

Bird charity warns of harm from new wind farm

The giant development lies 75 miles away from England's largest sea bird colony in Yorkshire.

www.bbc.co.uk

 

[Nutcracker]

When the turbine blades are 60 metres long? Unfortunately not.

One thing that has been found to work though, is to paint ONE of the 3 blades a different colour - black, or red, or something else contrasting; that makes the turbine rotation much more conspicuous, so birds avoid it more easily.

 

[YuShan]

I have seen video of wind turbines that detect the presence of big raptors nearby and stops rotating when they get too close. Of course that won't be implemented here, because too expensive and there are simply too many birds to make that a viable option.

 

[Deb Burhinus]

When the turbine blades are 60 metres long? Unfortunately not.

One thing that has been found to work though, is to paint ONE of the 3 blades a different colour - black, or red, or something else contrasting; that makes the turbine rotation much more conspicuous, so birds avoid it more easily.

Surely using a combination of ultra violet and fluorescent paint in solid colour would make more sense given birds see in the UV spectrum so have a ‘noisy’ visual environment in which turbine blades could get ‘lost’ - also one of the reasons why glass is hard to see -( using ultra sonic emission technology to repel bats would be an idea too perhaps ). It’s doubtful, that painting one blade black etc will avoid night collision (as birds would presumably see the black blade as a ‘gap’ which is the worst time for passerines since most smaller birds migrate at night.

edit - the technology YuShan mentioned seems like an excellent idea. Although most larger raptors don’t migrate over water so using it on off-shore farms might be less impactful than say, using such technology on high mountain tops on raptor migration flyways.

Unfortunately tracking research into flight paths of migrating birds and pelagic species is still in it’s infancy but there maybe future scope for mapping specific trans water migrants and siting off-shore wind farms more appropriately. https://www.bto.org/sites/default/files/publications/bto_rr725_final.pdf

It wouldn’t be a novel approach where human activity has been moderated to account for bird flight paths eg. The Jets of RAF Lossiemouth in Scotland adopted one such measure to reduce the number of winter Geese collisions when their jets took off and landed. The Geese were noted to always come in to surrounding fields from one direction. The base changed the logistics off their runways to accommodate the geese.

The question is, are birds like proverbial lemmings throwing themselves off cliffs, so ingrained genetically to follow a pre-ordained migration path that even if a 5 mile stretch of wind turbines were clearly visible, would they not still take the risk and still try to fly right through them? Could they even conceptually anticipate the danger of doing so? If birds had a heightened sense of anticipatory risk, I have some doubts they would even migrate the first place!

 

[YuShan]

It wouldn’t be a novel approach where human activity has been moderated to account for bird flight paths eg. The Jets of RAF Lossiemouth in Scotland adopted one such measure to reduce the number of winter Geese collisions when their jets took off and landed. The Geese were noted to always come in to surrounding fields from one direction. The base changed the logistics off their runways to accommodate the geese.

Of course this is not to protect the birds but to protect the planes. A Typhoon fighter jet costs £125 million each.

 

[Deb Burhinus]

Of course this is not to protect the birds but to protect the planes. A Typhoon fighter jet costs £125 million each.

Absolutely. Agreed. But the original proposal being mooted was to shoot the geese and use gas powered bird scarers to keep them off their winter feeding fields so both ‘won’ in the end.

 

[Andrea Collins]

Part of the problem with designing safeguards to protect birds from wind turbine blades and other unnatural obstructions in open air space seems to be that we look at the problem from a human perspective rather than the bird's perspective. Most birds have a view of the world that is literally very different to the view we humans have so something that makes wind turbine blades more obvious to us won't necessarily make them more obvious to birds.

There is a lot of interesting stuff about this in "The Sensory Ecology of Birds" by Graham R Martin (OUP 2017). Admittedly some of it is a bit over my head so this is a very brief and incomplete summary.

Some birds have very limited vision directly ahead and a very limited area of binocular vision. It may be necessary for them to turn or tilt their head to achieve a good view directly ahead. This wouldn't have been so much of an issue for birds flying in open space before humans started putting solid objects into said airspace.

Highest resolution in bird vision is often to the sides, not forwards. Some birds have a narrow band of high resolution across the middle of their vision but with less acuity above and below that.

Birds may often be using their lateral vision whilst flying to locate conspecifics, foraging opportunities or predators. Much of the time in open airspace these things may be more important than what is directly ahead so birds may simply not be looking ahead. Again this would have been less of an issue before human's came along and started cluttering up the airspace.

Birds flying in open air space may not predict that the environment ahead may be cluttered so simply fail to see something that to us would be obvious. To quote the above book directly, "Perceptually they have no 'prior' for human artefacts such as buildings, power wires, or wind turbines", all of which are relatively recent additions to the airspace.

Birds also seem to have some difficulty in assessing the speed of approaching objects which are not natural predators, which may perhaps be a significant issue with wind turbine blades.

Any mitigations need to take into account the fact that birds perceive the world in a very different way to us. There are unlikely to be any one size fits all options and the differing behaviour and visual capabilities of individual species may need to be taken into account.

Not all birds can see into the UV part of the spectrum either, so putting UV markers on obstructions won't help in all cases. There is, apparently, a trade off between UV sensitivity and high resolution. The precision with which light can be brought into sharp focus is inversely related to wavelength. So, if you want high resolution, it helps to filter out the shorter wavelengths including UV, which appears to be what happens in the vision of most raptors.

Just to quote a part of the conclusion from the collisions chapter in the above mentioned book, "......comprehensive solutions to the collision and entrapment problems are not yet available and considerably more work is required. It would be hoped, however, that humans will cease to view possible solutions to these problems from the perspective of their own sensory information and will attempt to approach it from the perspective of birds". The book does suggest a number of possible solutions but most currently seem to be a work in progress covering not just man made objects in open airspace, but also other hazards such as entrapment underwater in fishing nets, and as said, a lot more work is needed yet.