Approximately 10,000 species of birds are known on Earth. Just under half are migratory. A total of about 4,000 species of birds migrate back and forth between their breeding and wintering grounds. About two-thirds of them travel long distances, flying up to 20,000 kilometers a year.
Frequent flyer: the cuckoo.
And there are even more impressive figures. The cuckoo, for example, moves about eight months a year. Swallows fly up to 1,000 kilometers a day, and storks save up to 90 percent of their energy in gliding flight.
More and more migratory birds in danger of extinction
Many dangers lie in wait for the flight of migratory birds over the sea and the desert. But his worst enemy is the human being, because of his way of life, because of the consequences of climate change or because of his activity as a hunter. According to the Red List, 43 percent of bird species that breed in Germany alone are threatened with extinction, including many migratory birds.
Millions and millions of birds die each year in collisions with glass.
After the loss of their habitat, the collision with glass is the main cause of death of birds. An estimated one billion birds are killed in this way each year in the United States alone. The birds do not recognize the reflections of the trees or the sky in the glass, they fly towards them and crash. Just as weaker migratory birds can die on the journey from the effort, glass also kills strong animals with better chances of having offspring.
Swans are also migratory birds attracted to city lights.
The good news is that these types of accidents can be easily prevented, for example by applying a special sheet to reduce reflection. In contrast, silhouettes of birds of prey have been shown in studies to be completely ineffective as a deterrent.
Although wind turbines can be dangerous to birds, there are ways to reduce the risk.
A recent British study shows how migratory birds are especially likely to be killed by wind turbines located along their routes, such as the German Baltic coast, the western Mediterranean coast of France and the southern coast of Spain. However, the study also shows that there are many locations for new wind turbines where the risk to animals is significantly lower.
Power lines are more dangerous than wind turbines
There are also direct ways to avoid bird collisions with wind turbines, such as sensors that automatically turn off the turbines when birds approach. Norwegian researchers found in a random sample that painting rotor blades black makes birds better able to recognize wind turbines and avoid them.
More birds die on power lines than on wind turbines.
According to the study, many more birds die from collisions with power lines than with wind turbines. Especially for low-flying animals, they pose a great danger. In this case, it might also be useful to mark the power cables more conspicuously.
Songbirds get caught in the nets on many Mediterranean beaches.
But people sometimes kill migratory birds on purpose. In the Mediterranean alone, some 20 million wild birds are illegally hunted every year, illegally shooting them.
Illegal hunting of wild birds
Whether in Egypt, Italy, Cyprus, France, Malta or Lebanon, wild birds are considered a delicacy in many Mediterranean countries. Most are sold on the black market to restaurants or private individuals.
Catching birds using the glue technique is prohibited throughout the EU.
Caught in nets, with various traps or with sticks smeared with glue, the birds often die in terrible agony. Bird hunting with glue is prohibited throughout the European Union. In 2021, France, the last country to allow this practice, also declared this technique illegal.
How climate change affects migratory birds
Climate change also influences the behavior of migratory birds. Due to the milder winters, more and more birds are deciding to give up their journey and remain in their breeding grounds throughout the year. Most are partial migrants, that is, bird species such as the robin, in which some individuals tend to migrate and others do not.
Birds that skip the trip can secure the best spring breeding sites.
But short- and medium-distance fliers, such as starlings, increasingly remain in their summer roosts throughout the year. The advantage is that those who stay in the breeding area during the winter are the first to arrive at the nesting site in the spring and can find the best habitats and reproduce better. A disadvantage for those birds that move away during the winter.
The nightingale will face more trips in the future.
For long-distance migratory birds, climate change is causing big problems. According to the Royal Society for the Protection of Birds, more than 80 percent of Europe’s long-distance migratory birds already have to fly longer and farther to find wintering grounds with enough food. According to the researchers, it is likely that the nightingale will have to travel about 800 kilometers further in 2070 than it does now.
The black warbler benefits from the milder winters.
Instead of moving to Spain and North Africa, as was the case a few years ago, a large proportion of Blackcaps now migrate from Central Europe to Great Britain in winter. The increasingly temperate climate makes hibernation possible. Another clear advantage: the flight distance is much shorter and there are no dangerous glue sticks or booby traps lying in wait.