New Year's Eve is particularly stressful for birds

Welcoming the new year with a large, loud fireworks display – this is a long-standing tradition.

But for Wildlife , this means pure stress. A study shows that the consequences for wild geese, for example, still reverberate days later.

GPS data reveal dramatic flight responses

Fireworks may look beautiful, but the whistling rockets and the fine particulate matter they produce mean stress, particularly for wildlife. Researchers from the Max Planck Institute for Animal Behaviour in Konstanz and the Netherlands Institute of Ecology observed how New Year's Eve affects wild geese over eight consecutive years. For this purpose, birds were fitted with GPS transmitters. The results show that the fireworks affect the animals for longer than just one night.

According to the study, movement data from 347 geese in northern Germany, Denmark and the Netherlands were analysed – each time covering the period from 19 December to 12 January. The findings show that on New Year's Eve, the geese fled their roosting waters precisely at midnight and flew to areas with fewer people. The animals' night-time rest was shortened by two hours. Fine particulate pollution over their resting zones increased by up to 650 percent.

According to the researchers, the geese flew up to 16 kilometres further and up to 150 metres higher than usual. In individual cases, extreme distances of more than 500 kilometres were also covered. According to the analyses, the animals recovered from this exertion only slowly.

«Shocking to see»

«It is shocking to see how much further the birds flew on New Year's Eve,» says study author Andrea Kölzsch of the Max Planck Institute for Animal Behaviour. «Some animals covered hundreds of kilometres in a single winter night – distances they would normally only cover during migration,» the scientist explained.

Four goose species were observed: the greater white-fronted goose, the barnacle goose, the pink-footed goose and the bean goose. These are arctic Migratory birds, which spend their winter in northern Germany, Denmark and the Netherlands. Normally, the animals feed or rest all day in order to use as little energy as possible.

Energy loss and long recovery time

However, fleeing on New Year's Eve costs the geese a great deal of energy. To recover it, they subsequently rested noticeably more afterwards. They ate ten percent more and moved significantly less during the day. «In harsh winters, where not enough additional food can be found or cannot be consumed quickly enough during the short days, this may lead to problems,» explained Kölzsch. The study was published in the journal «Conservation Letters» at the end of November, around a month before the start of firecracker sales on 29 December.

Other animals also suffer on New Year's Eve. «However, the reactions to this disturbance differ from species to species,» said Kölzsch. A songbird in a nesting box will press itself into a corner and compensate for the shock with an elevated heart rate or a lot of hopping back and forth, a wild boar might hide in the undergrowth, and wild geese, which naturally flee into the air when in danger, would simply fly away.

Even smaller explosions on New Year's Eve would be enough to enormously frighten the animals. This was shown by analyses from the Covid years, when setting off firecrackers was only possible to a limited extent in many countries.

Addendum from 7 October 2026: On 29 November 2026, Switzerland will vote on the fireworks initiative, which aims to ban the sale and use of noise-generating fireworks. You can read what this means for wild animals in our article Fireworks initiative on 29 November: what's at stake for wild animals.