As we transition towards renewable energy solutions, due to the climate crisis, wind power stands out as the leading alternative to fossil fuels. However, there is a growing concern regarding the negative impacts that windfarms can have both on wildlife and landscape. Collision with electric infrastructures and electrocution are one of the leading causes of mortality for birds, especially raptors. Luckily, several strategies to reduce bird mortality have been studied. Balancing renewable energy development with wildlife conservation is not only possible, but crucial for a future where both clean energy and biodiversity can coexist and thrive.
The global transition to renewable energy is vital for mitigating climate change and addressing the increasing energy demand. Wind power nowadays plays a key role in this transition with the production of approximately 25% of renewable energy globally. Nevertheless, as we build a greener future, we must consider the impact of these technologies on wildlife. Wind turbines and powerlines constitute a leading cause of mortality for birds and bats. Vultures, as large soaring raptors, are one of the most impacted groups.
According to our data, based on thousands of records of vulture mortality we hold in our European Vulture mortality database, electrocution on medium-tension electricity pylons is the second most important cause of vulture mortality at continent scale, and in some countries has become the main threat. Collision on windfarms can also locally be a significant cause of mortality, and it has been proved that in some populations (e.g. Egyptian vulture in Andalusia) have population level impacts.
We are now facing a pivotal moment. Can we harness wind energy and taking care of vulnerable species at the same time? Scientists, energy providers, governments and NGOs are working together towards several strategies to ensure that the green transition does not come at the cost of biodiversity.
Why are vultures so impacted by wind turbines?
Vultures are built for soaring. The giant wingspan that makes them so majestic and allows them to glide on thermal updrafts, makes them also particularly vulnerable to wind turbines. Their large bodies and long wings are very hard to manoeuvre, making them less capable of avoiding unexpected obstacles, especially if they are moving fast.
In addition to their flight style, they have a unique vision field tailored to scanning the ground for carcasses. When they fly, they have a great visual coverage below themselves, and significant blind spots ahead and above them. This makes it difficult for them to spot and avoid wind turbines placed in their line of flight.
Lastly, the same currents that are ideal for vultures to gain height and fly large distance without too much effort, are the most efficient for wind turbines to make energy. The overlap between ideal habitats for vultures and turbine sites increases the likelihood of collisions.
Vultures are long lived species characterized by late sexual maturity and low reproductive rates. They mature around three to four years old and lay one or two eggs per year. Most vultures are also endangered all over the world. Taking these factors into account helps us understand how impactful the loss of even one individual can be on the survival of the entire populations.
Collisions and electrocution: a combined impact
Europe counts 23.400 onshore windfarms, with over 113.000 wind turbines. These numbers are destined to increase in the next years, therefore we need to consider which factors influence the impact of windfarms on vultures’ populations.
- Windfarms positioning – vultures and wind turbines use the same thermal currents, so windfarms are often positioned in areas highly frequented by vultures
- Turbine size and rotor speed – higher and faster turbines are associated with an increased risk of collision
- Turbine location and distribution – wind farms arranged perpendicular to the main flight paths are associated with more collisions. The same happens for isolated turbines. Groups of turbines located next to each other might be easier to identify and avoid for birds than those positioned at the end of a row or isolated.
In addition to collisions with energy infrastructures, vultures are also prone to electrocution in electric pylons. When they perch, their large wingspan increases the probability for them to touch two electric lines at the same time, leading to electrocution. Only in France, there are 1.4 million km of medium tension power lines (equivalent to 35 times the Earth’s circumference!) which could potentially become an electrocution hazard for vultures.
A less visible impact, of powerlines and wind farms is how they act as barriers for vultures. They fragment and degrade important habitats and disrupt flight paths between roosts, breeding sites and foraging grounds. Combined with other threats such as poisoning and food shortage Energy infrastructure contribute significantly to cumulative pressures on vulture populations, hindering their recovery and exacerbating population declines.
A blueprint for coexistence
Despite the grim reality, there is still hope. The conservation community, policy makers, and energy companies are not blind to the problem. The key lies in combining innovative technologies with thoughtful planning, an adequate regulatory framework, and detailed knowledge of the species.
Avoidance
The most effective approach is placing energy infrastructures strategically., avoiding key areas where vultures commonly fly, roost or forage. Sensitivity mapping and habitat modelling using data on vultures’ movements can help identify high-risk areas that must be avoided. Ideally, electric infrastructures should also be positioned near areas that present already elements of disturbance for vultures in order to minimize further habitat fragmentation. In the case of wind turbines, they also should be oriented parallel to the main direction of flight rather than intercepting it.
Regulation
An adequate regulatory approach, either on planning windfarm developments, or on mitigating existing infrastructure, should also be introduced, so that biodiversity impacts are considered as a normal part of the operation of the energy, and factored in the budgets, costs and results. In some countries in Europe utility companies are already obliged to act following any electrocution mortality, as part of their environmental liability, and this has helped expand mitigation work.
Mitigation
If building these infrastructures in key areas for vultures is unavoidable, implementing effective mitigation measures becomes crucial.
A promising solution for existing wind farms is the use of real-time detection systems. Radar and camera systems supported by observers can detect approaching birds and temporarily shut down turbines on demand. This method has been successfully implemented in southern Spain and Portugal After 13 years, vulture mortality rates dropped over 70% without significantly impacting the productivity of the wind farm.
Habitat management is also a good mitigation tool. For eample, actively reducing food availability in these area whlie creating new artificial feeding stations, vultures can be driven to safer areas.
Compensation
Compensation is the least desirable option. It implies that energy companies pay a fee or finance conservation actions somewhere else to counterbalance the impact of their infrastructure on local vulture populations.
A way forward
As renewable energy becomes increasingly central to our fight against climate change, it’s essential that we find ways to take care of biodiversity at the same time. Vultures are vital for the health of ecosystems. Feeding on carrion they reduce the amount of carbon dioxide released in the atmosphere by decomposition or incineration. By eating dead animals, they also help reducing potential diseases from the environment. Their decline could have cascading consequences on ecosystems and humans.
The good news is that we don’t have to choose between renewable energy and vulture conservation. With smart planning, good regulations, innovative technologies, and a commitment to protecting biodiversity, we can find ways for wind energy and wildlife to coexist.
In this new era of renewable energy, we must ensure that the solutions we implement today not only power our future but also preserve the rich diversity of life on which we all depend. Scientists, conservation organizations, energy developers, and policymakers must work together to promote solutions that protect vultures while supporting the expansion of renewable energy. The future of both green energy and wildlife conservation depends on our ability to balance these two goals in a sustainable way.
