The annual odyssey of migratory birds is unique, spectacular, fascinating. It is also fraught with danger, not just from poachers and hunters and the new threat called climate change, but from us too – people who wouldn't want any harm to come to these creatures. The newest nemesis for these birds is our insatiable need for energy. Hundreds of thousands of birds die annually from electrocution the world over, and tens of millions of birds from collision with power lines alone.
Just as the migration of birds transcends international boundaries, so does the problem. Wind turbines in the Smöla archipelago of Norway is said to have contributed to the waning of the local breeding population of white-tailed eagles. The 5,000 turbines in the Altamont Pass in California, US, kill about 1,000 of these raptors every year. It is feared that 12 per cent of the blue cranes in the Overberg area of the Western Cape in Southern Africa die annually in power line collisions. Some 15 per cent of Ludwig’s bustards are killed annually in collision with high voltage transmission lines.
Modifications to power lines and structures can reduce the electrocution risk to birds by 50 per cent. Actions include:
- Removing redundant power lines;
- Burying power lines (effective, but expensive);
- Marking power lines or wind blades at least every 5-10 metres to make them more visible to birds i.e. with high-contrast, reflective or moving markers;
- Replacement of dangerous structures with bird-safe designs;
- Additions of safe perches and nesting platforms;
- Insulation of cables close to poles;
- Increasing the distances between electric conductors and grounded hardware.
The problem is global, and its scale would seem unending. Consider a few numbers go gauge the extent: by this year-end, there will be 76.2 million kilometres of power lines throughout the world. Over the next five years, another 5 million kilometres of new power lines would be constructed. Given the fact that power lines are often erected with minimal consideration of their environmental impact in most countries, it would not be wrong to contend that things might just worsen for migratory birds.
Power generation and energy distribution have only added to the threat that migratory birds are under. From growing human population and rapid urbanisation to climate change and unsustainable use of landscapes have resulted in the fragmentation and degradation of the natural habitats upon which migratory birds depend. Many of the places used by migratory birds to rest, feed and breed during their annual migration cycles are no longer what they were even fifty years ago.
A total of 2,274 species (roughly 23 per cent of the world’s birds) are considered migratory according to the definition of migratory species accepted by the Convention on the Conservation of Migratory Species of Wild Animals (also known as CMS, or Bonn Convention). Of these, about 800 (about 35 per cent) are currently covered by CMS and its related instruments. Almost 14 per cent (317) of the migratory bird species are considered threatened or near-threatened (17 Critically Endangered, 50 Endangered, 128 Vulnerable, and 122 Near Threatened) based on the 2010 IUCN Red List.
Birds of prey like the Egyptian vulture, Griffon vulture, eastern imperial eagle and common kestrel are all vulnerable to energy infrastructure, especially wind turbines and overhead power lines. The same goes for soaring birds like the oriental stork and Eurasian crane. Fatalities of these rators, cranes, bustards and owls expand in significance considering the fact that many are of them are slow-breeding birds. Even small losses can cause some populations to dwindle, resulting in local or regional extinction.
Efforts, of course, are under way. The theme for World Migratory Bird Day 2015 was “Energy – make it bird-friendly!” A Resolution on Renewable Energy and Migratory Species adopted by CMS Parties at their November 2014 Conference held in Quito, Ecuador, called for Strategic Environmental Assessments (SEA) and Environmental Impact Assessments (EIA) to be carried out when planning the use of renewable energy technologies, avoiding existing protected areas and other sites of importance to migratory species. With specific reference to wind energy, the resolution urged for undertaking careful physical planning with special attention to the mortality of birds (in particular of species that are long-lived and have low fecundity) resulting from collision with wind turbines. [World Migratory Bird Day, observed since 2006 during the second week of May every year, is organised by CMS and the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).]
The clue to avoiding or mitigating negative impacts on migratory birds lies in understanding specific migration routes and the importance of particular habitats. Therefore, location, design, abundance, construction, operation and maintenance of energy installations should to be carefully selected to avoid key breeding, feeding, resting, overwintering sites and migration routes for birds. This is where the SEAs and EIAs come in. There would be hardly anything “sustainable” about renewable energy production (necessary to arrest climate change), if these result in inadvertent species decline.
Many countries have understood the problem, and are already taking corrective measures. All low and medium voltage cables have been buried In the Netherlands, Belgium, Denmark, Germany, Norway and the United Kingdom. Hungarian NGO MME has developed a plastic cover for the metal struts of pylons. Since 80 per cent of white storks in Hungary perch and build their nests on electricity poles, safety platforms have been installed to prevent the birds from electrocuting themselves. Temporarily shutting down of wind turbines at specific locations during specific times such as the peak of the migration season has proven to be effective as well. In Spain, the number of Griffon vultures killed because of wind turbines have dropped by half for a loss of power generation of less than 0.1 per cent.
Migratory birds don’t belong to any country in particular; they are everyone’s responsibility.
