German Bird Populations Face Mixed Recovery After Harsh Winter and Avian Flu Outbreak

Germany's bird populations are recovering from a harsh winter, but kingfishers suffered a decline of 80 percent or more and roughly one in ten of the 400,000 cranes that migrated over Germany in autumn died of avian flu, according to experts. Martin Rümmler, bird protection expert at the Nature and Biodiversity Conservation Union (NABU), said most species managed the cold season reasonably well given how severe conditions were. The core problem for many birds was not low temperatures themselves but the loss of access to food caused by snow and ice cover. Frozen water bodies proved especially damaging for water birds and fish-eating species, which could not reach food through the ice. Barn swallows are currently arriving from their winter quarters south of the Sahara, and house martins are expected to follow shortly. All breeding birds are expected to be back in Germany by mid-May at the latest.

„They have mastered the winter well, considering that it was quite harsh.” — Martin Rümmler via ZEIT ONLINE

Bird populations in Germany face seasonal pressure from a combination of winter cold, food scarcity, and disease. Avian flu has been a recurring concern across Europe for several years, with outbreaks affecting wild and domestic bird populations. The kingfisher is known to be particularly vulnerable to hard winters because it depends entirely on open water to hunt fish. Crane populations have grown significantly across Germany and Europe in recent decades, making them one of the more robust migratory species on the continent.

Kingfishers hit hardest, but recovery expected within years Derk Ehlert, Berlin's wildlife expert, said the kingfisher was "really hit" by this winter's conditions, with the species recording a decline of 80 percent or more. Cormorants did not freeze to death but starved because they could not reach fish through the ice layer covering water bodies. Ehlert said kingfishers can compensate for such losses through so-called overlapping clutches, a strategy in which the birds produce multiple successive broods in a single season. He estimated that a normal kingfisher population could return within three to four years. A spokeswoman for the Brandenburg Nature Conservation Union noted that losses in the animal world are usually compensated for in later years, provided that other pressures — such as declining insect populations — do not worsen simultaneously. Rümmler added that the grey partridge may also have suffered greater losses due to snow cover restricting access to seeds and insects on the ground, though the full extent will not be known until next year at the earliest.

80% (decline) — Kingfisher population drop after frozen winter

Cranes return in smaller groups, reducing flu risk for now Avian flu remains a concern for Germany's bird world, though experts say the risk is currently lower than in autumn due to changes in crane behavior during the spring migration. Unlike the southward journey in autumn, when cranes gather in very large numbers at staging sites, they travel in relatively small groups on the return flight in order to reach their breeding grounds quickly. Rümmler said this behavioral difference significantly reduces the probability of infection spreading between birds. He noted that one possible additional factor is that the virus may have changed or that some degree of immunity has developed in the crane population. In Berlin, avian flu was detected in 100 out of 498 examined dead wild birds, according to figures from the Senate Department for Consumer Protection reflecting the situation as of March 5, 2026. Ehlert warned that by September and October, when birds again congregate closely during the southward migration, avian flu could spread more strongly once more.

100 (birds) — Avian flu cases in Berlin wild birds examined by March 5, 2026

Examined dead wild birds: 498, Positive for avian flu: 100

Spring moisture key to offsetting winter losses, experts say Storks have already arrived in Brandenburg, while greylag geese and cranes have largely returned to Berlin, Ehlert said. The nightingale is expected to follow as a summer guest by mid-April, with all Berlin birds back by mid-May. Rümmler stressed that the success of the spring breeding season depends heavily on rainfall: if conditions do not become too dry, plants and insects will thrive and provide the food base birds need for successful reproduction. He said that winter losses could be "actually canceled out or compensated for relatively quickly" if food sources remain abundant.

„Any losses from the winter would then be actually canceled out or compensated for relatively quickly.” — Martin Rümmler via ZEIT ONLINE

Ehlert echoed the cautiously positive assessment for the region overall.

„The hard time is over, the Berlin winter bird world has survived it.” — Derk Ehlert via N-tv

Both experts framed the current situation as one of normal population fluctuation rather than structural decline, while acknowledging that the full picture of winter losses will only become clear through monitoring data gathered over the coming year. The Brandenburg Nature Conservation Union noted that native species have evolved strategies to cope with cold, snow, and ice, and that resilience is built into their breeding biology — provided human-driven pressures such as habitat loss and insect decline do not compound natural setbacks.