Often called a ‘natural miracle’, ‘awe-inspiring’, and ‘one of the wonders of the natural world’, the regular migration of birds across huge distances has fascinated observers around the world for centuries. Involving intricate migration patterns, unerring navigation skills and astonishing stamina, global flight patterns reveal not only the natural obstacles on journeys that can span thousands of kilometres, but the real – and growing – threats posed by humans.
“Dim the lights for birds at night”
Saturday 14 May marks World Migratory Bird Day (WMBD), which this year will focus on one such man-made threat: light pollution. Surrounded by artificial light, from mobile and TV screens to lampposts and electric billboards, it is easy to become desensitised to the fact that artificial light is increasing globally by at least 2% per year. The WMBD Strategy 2022 reveals that today, more than 80% of the world’s population lives under a “lit sky”, a figure closer to 99% in Europe and North America; as do the species we share the skies with.
Studies have shown that light is a key factor in migration patterns. Migratory birds navigate by the sun during the day and the stars at night, and are even able to detect polarized light; precise calibrations that are disrupted by artificial light. Many migratory bird species fly at night, when artificial light poses a serious threat. As the WMBD Strategy details, light pollution disorients nocturnally migrating birds and attracts them to circle in illuminated areas, depleting their energy reserves and putting them at risk of exhaustion, predation and lethal collision with illuminated buildings and other brightly lit structures. Light pollution also risks seriously altering migratory birds’ behaviours, from migration and foraging to vocal communication, and disturbing their precise internal clocks.
Possible solutions to the threat of light pollution have inspired the slogan of WMBD 2022: “dim the lights for birds at night”. More and more cities in the world are taking measures to dim building lights during migration phases in spring and autumn, while new international guidelines focusing on migratory landbirds are currently being developed under the Convention on Migratory Species to draw up a global plan of action.
Connecting countries, continents and cultures: BirdLife International
To mark this year’s WMBD, UNRIC spoke to Barend van Gemerden, Global Flyways Programme Coordinator at BirdLife International, an organisation which this year marks its 100th anniversary as a global leader in avian conservation.
Why do birds migrate?
Many millions of birds travel each year from their breeding grounds to their wintering grounds, and back. Many undertake epic journeys of over 10,000 kilometres, others fly over the highest mountains of the Himalaya.
In general birds migrate to benefit from more food and avoid too harsh conditions. For instance, winter visitors to the UK, from field fares to geese, enjoy the abundance of berries and grass and the relative mild weather during the winter. In the spring they return to the much more northerly breeding grounds. They time their departure to coincide with the melting of the snow and ice to quickly build a nest and lay eggs.
What are the greatest obstacles currently facing migratory birds today?
Migration has evolved over millennia. It is a perfect system to maximally benefit from the diversity of conditions in different places. However, it is also a delicate system because changes in one place can impact the fate of the whole population. Connectivity is what makes bird migration so fascinating, but is also the biggest challenge for nature conservation. Especially now that changes are taking place in sites and landscapes throughout the flyway, the cumulative effect is enormous. And despite the good efforts of many to make migratory birds feel welcome, the overall picture is not looking good.
Agricultural intensification is a threat to many breeding birds. The rise of monocultures and heavy use of pesticides and other agrochemicals is bad news for insects and other sources of food for birds. In many parts of the World, migratory birds have traditionally been a rich source of protein and hunting is still widespread despite more rigorous laws. Many birds breeding in the UK and Ireland face an untimely death while trying to cross the Mediterranean region. A BirdLife-led survey estimated that some 25 million birds are killed illegally each year in this region alone.
Other threats to migratory birds are the loss and degradation of key sites. In particular, coastal wetlands, often located near to cities, are rapidly being transformed into industrial estates, housing complexes, harbours and airports. Migratory birds, especially the bigger ones such as pelicans, storks and eagles, risk colliding with wind farms and power lines. Development of new structures need to be carefully chosen to avoid areas where many birds pass. Old energy infrastructure needs to be made as bird-friendly as possible.
Brightly lit cities also disturb migratory birds, especially those that migrate at night. A massive number of birds die each year as a result of hitting sky-scrapers. And then there is climate change – the threat that makes all of the others even worse – from sea level rise that flood coastal areas, to the drying out of wetlands, to increased storm events that make migration even harder.
How important are the UK and Ireland as stopping points for migratory birds?
Of about 11,000 species of bird worldwide, some 2000 are migratory. Many birds follow distinct pathways when migrating, called Flyways. The UK and Ireland lie on the East Atlantic Flyway, which stretches from Russia, Greenland and Canada all the way to Southern Africa.
Some birds migrate slowly, stopping underway, while others make long haul flights. Crucial for all is that there are places to recover from the hard work of flying over large distances, where they can feed and rest and prepare for the next leg of their journey. The UK and Ireland are important for a wide range of species. For migratory breeding birds, these countries are the starting point of their journeys. For water birds such as ducks, swans, geese and waders, the UK and Ireland are often the wintering grounds, although quite a few only make a short stop in the UK and Ireland and continue their journeys to warmer places.
What are some of the projects that BirdLife International is currently involved in, in the UK and Ireland as well as globally?
BirdLife International is a global partnership of 117 national organisations, and all of the work for migratory birds by the BirdLife Partnership comes together in the BirdLife Global Flyways Programme. Within the Flyways Programme, we focus on four priority themes: conservation of coastal wetlands, stopping illegal killing of migratory birds, reducing the risk of collision and electrocution with energy infrastructure, and sustainable land use.
In the UK, our national partner is the Royal Society for the Protection of Birds (RSPB) and in Ireland, Birdwatch Ireland is representing BirdLife International. Both organisations are doing amazing work to protect migratory birds while they are in their territories through research, education and outreach, engaging communities in bird surveys, maintaining nature reserves, and advocating and campaigning for birds.
What can people do to get involved in supporting BirdLife International and migratory birds?
Birdwatching and recording the species that you see and hear can help scientists to keep track of bird numbers and how they are changing around the world. This shows which species and habitats are under threat, allowing conservationists to act to help them. Young people can get involved through our Spring Alive project, but there are many other projects around the world and apps such as eBird where you can log your sightings from anywhere in the world.
You can support BirdLife by becoming a member of the World Bird Club, which will help us to save birds from extinction, support disadvantaged communities in key wildlife spots and help protect vital habitats from the many threats they face today.
Taking action to help support migratory birds can even be as simple as going into the garden and getting your hands dirty. The RSPB has recently appealed to the public to create mud pies in order to give returning migratory birds a head-start on collecting materials to build their nests following the recent mini-heatwave. They also recommend leaving out dishes of fresh water, putting up artificial nests and boxes, and creating insect-friendly gardens, tips for which can be found in our previous UNRIC article on butterflies and biodiversity.
Whether by switching off a light, putting out supplies or picking up a pair of binoculars, WMBD 2022 is an opportunity to protect a natural phenomenon that is as important as it is beautiful.
Click here for more ways to support BirdLife International’s work, and sign up to their newsletter or follow them on Twitter, Facebook and YouTube to keep up with the latest bird and conservation news.