A large goose with grey-brown plumage. In Europe it lives in vegetated wetlands and surrounding grassland.
The upper feathers have pale edges and the belly is white. The head and neck are also grey-brown, and the bill is large and robust.
Greylag geese showed changes inside their bodies during a night of New Year’s fireworks. In a flock living in Austria’s Almtal, heart rate and body temperature rose between midnight and 02:00 as fireworks brought light and noise to the night.
The study, published in 2022, examined 20 freely flying geese from a flock that received supplementary food and was accustomed to people nearby. Recording devices measured heart rate and body temperature, allowing comparison with the same hours on the previous day and during December and January. Mean heart rate between midnight and 01:00 was approximately 96% above the December average for that hour.
The two physiological responses followed different time courses. Elevated heart rate was detected until 02:00, while elevated body temperature lasted several hours longer. By 05:00–06:00, temperature had returned to levels comparable with the other periods. The fireworks night was associated with changes extending into the hours before dawn.
An extinction-risk assessment has not been added yet.
Avoiding intense fireworks disturbance around night roosts is a conservation concern for greylag geese. The authors of the Austrian study recommend avoiding fireworks in natural areas. Physiological responses even in human-habituated geese support reducing disturbance from light and noise around resting places.