Wintering of cranes – record numbers along the Vistula River

Until recently, the wintering of cranes (Grus grus) in Poland was a marginal phenomenon, with most of these majestic birds migrating to southern Europe, mainly to Spain and France. However, in recent years, their presence in the country during the winter months has become increasingly common. The Vistula River, especially its sandy bars, now attracts hundreds, even thousands, of cranes that choose to remain in Poland.

Why is wintering of cranes becoming more common?

The increasing trend of cranes wintering in Poland can be attributed to several key factors. Primarily, climate change plays a significant role – milder winters mean that birds do not need to undertake exhausting migrations to western and southern Europe. The absence of prolonged frosts and minimal snow cover allow them to find food more easily. Cranes are omnivorous birds, feeding on both vegetation and small invertebrates. In the Vistula River valley, they find ample food on agricultural fields, near wetlands, and on exposed riverbanks.

Habitat conditions are also crucial. The Vistula River, being a large watercourse, has preserved its natural character in many places. As a result, it offers cranes ideal spots for rest and roosting. Sandy bars, especially during prolonged low water levels, provide safe havens from predators, encouraging the birds to winter in these areas.

A decade ago, a year ago, and now…

An analysis of data from the winter of 2015/2016 from the ornitho.pl platform clearly shows how dynamically the situation of wintering cranes in Poland has changed. A decade ago, observations of these birds were much rarer, limited to a few locations, mainly in the western part of the country. At that time, the Vistula played a marginal role as a wintering site, with most of the population continuing traditional migrations to southern Europe. In the 2015/2016 season, only 60 crane observations were recorded.

Comparing this data with last winter, there is a significant increase – the number of reported observations reached over 1,800. In the current season, the number of reported observations so far is approximately 2,500. This year, cranes have particularly favored the Vistula River valley.

Low water levels in the Vistula River have exposed numerous sandy bars, providing optimal conditions for foraging and rest. As seen, changing climatic conditions and food availability are making the Vistula one of the most important crane wintering sites in the region.

Is it good that cranes stay for the winter?

In an interview on the “Czysta Polska” program, Łukasz Wardecki, Coordinator of Bird Monitoring at OTOP, noted that the wintering of cranes in Poland can be a beneficial phenomenon. Birds migrate because, over millions of years, they were forced to – it’s how they evolved, and migration was a survival strategy. However, each migration involves enormous effort and high mortality within the population. By staying in Poland, more cranes avoid the exhausting journey and the numerous migration-related threats, such as food shortages, predators, or collisions with infrastructure. The closer the birds remain to their breeding grounds, the greater the chance they will safely return to these areas in the spring.

On the other hand, staying for the winter can also be risky. Sudden weather changes, severe frosts, or prolonged snowfall can make it difficult for birds to find food, leading to their weakening or death. Therefore, the trend of cranes wintering in Poland carries both benefits and potential risks.

The future of wintering cranes in Poland

All indications are that if current weather conditions persist, more cranes will choose to winter in Poland. Ornithologists will closely monitor further changes in their migrations, and the protection of bird habitats along the Vistula will become even more significant in the context of nature conservation strategies. For crane enthusiasts, this is an excellent opportunity to observe these beautiful birds in their natural environment, even in the middle of winter.