Ornithologists point out that birds have different migration strategies, and the routes they take to get to their wintering grounds differ. Moreover, this path is not at all easy, reported the Latvian Television program "Nature Facts".
The white-tailed eagles, which have been a favourite on live webcams for many years, stay at their nesting sites all year round. The black-tailed godwit, on the other hand, generally winters in southern Europe, but if the winter is mild and the waters do not freeze, it can also stay in Latvia.
The category of long-distance migrants includes the osprey, which goes to Africa for the winter. The osprey is unique in that it is one of the first to fly away from Latvia in autumn and one of the last to fly back in spring. It winters in South Africa and is currently most likely somewhere near the Sahara. But the osprey migrates across the Mediterranean Sea and winters mainly in western Africa.
The lesser spotted eagle, as well as the white and black storks, also spend the winter in Africa. The white stork's wintering area extends all the way to southern Africa, while the black stork stays in a more concentrated area - between the Sahara and the equator. The storks are currently migrating over Bulgaria, Turkey and Israel.
Each bird species has a different flight strategy. Birds with large wingspans, such as eagles, vultures, and storks, use rising air currents. They circle more than a kilometer high and then glide downward.
Ornithologist Jānis Ķuze explained: "It has been calculated that, compared to active flight, when birds move their wings, this gliding allows for up to 20 times more energy savings."
Larger birds - geese, swans, gulls, cranes - fly in groups, while smaller birds - in flocks.
Ornithologist Dmitrijs Boiko pointed out that two-thirds of birds migrate at night: "It's safer at night, and then birds navigate by the stars and the moon. Geese and swans can migrate both during the day and at night. But there are also species - not many - that migrate only during the day [such as] for example, finches."
When covering such long distances, serious obstacles abound. Storks and eagles try not to fly across the Mediterranean Sea, but ospreys cross it to have to fly a shorter distance. Ospreys fly over the Sahara, which is a very significant obstacle on the birds' way, because there can be problems with feeding there.
Ornithologists have been using bird ringing to study bird migration routes for over 100 years. Modern transmitters provide precise information about the location of birds, but they are not always possible to use.
Boiko explained: "For the most part, we know the migration routes, especially for larger birds that can be tagged. With ringing, you can't tell exactly where the birds fly through, where they winter; especially if we're talking about those that winter in Africa. Birds don't fly to the same part of Africa along the same route."
Migration is not a romantic journey, it is a time full of challenges. Ornithologists draw attention to the fact that bird migration is directly affected by climate change. "As a result of climate change, wetlands are disappearing a lot. This means that it is becoming more difficult for bird species that are associated with wetlands - the same black stork - to find food along the migration route," Ķuze pointed out.
On their long journey, birds face dangers posed by power lines and tall buildings.
"It's no secret that in Europe alone, millions of birds crash into windows because they see a reflection there - of the moon or stars," Boiko pointed out.
In Western Europe and the Middle East, some bird species are hunted - for food, entertainment or feathers. Despite the fact that this hunting is not legal, people are simply used to doing it. This is the situation in Malta, southern France, Italy. There are even regions where owls and jays are actively hunted. In Africa, storks are hunted and eaten.
"Our green crows, which we protect as a huge treasure and each bird has known parents for several generations - they are shot in the Mediterranean region, because it is a tradition there. There are Arab countries where the green crow is considered elite game," Ķuze said.
Bird conservation is perceived differently in each country. In regions of Africa where there is human conflict, nature conservation unfortunately remains secondary, and war directly affects bird migration.
"What is happening in Ukraine is also affecting migratory birds. It is known that birds can change their migration routes to avoid war zones. There are studies that have proven this using birds equipped with satellites," explained Ķuze.
Autumn migration takes a longer period, and long-distance migrants are still on their way to their wintering grounds, but at the end of February, we can expect the first birds to fly back to Latvia and the cycle of arrival and departure to continue as it always has.