Fireworks Have Long-Lasting Impact on Wild Birds

When blasts of fireworks are lit in celebration of the New Year, wild birds often experience harmful lasting effects.

An international team of researchers tracked Arctic migratory geese as they traveled in Denmark, Germany, and the Netherlands over eight New Year periods to study the impacts of fireworks. Data from 347 geese showed that birds abruptly leave where they are sleeping on New Year’s Eve and fly farther away from where people are.

Birds whose lives were disrupted by the noise and flashes ended up resting two hours less and sometimes flying nonstop as far as 310 miles (500 kilometers) compared to the nights when there were no fireworks.

But their changed behavior didn’t end with the fireworks. The geese didn’t return to their original sleeping locations and spent more time foraging to replenish energy for days after the celebrations ended.

Study first author Andrea Kölzsch, a research scientist at the Max Planck Institute of Animal Behavior in Germany, said the team members had been working with Arctic geese in Western Europe for more than 10 years, tracking several with GPS and analyzing their movements in relation to weather, climate, and other factors.

Kölzsch spoke to Treehugger about the work. The findings were published in the journal Conservation Letters.

Treehugger: What was the impetus for your research?

Andrea Kölzsch: When looking at the tracks once in a while out of interest, several interesting individual behaviors become apparent. One of them was that some of the geese flew extreme distances during New Year’s Eve.

As it is known already from radar studies and observations that wild birds are strongly disturbed by the widespread, intensive customer fireworks activity that takes place around New Year in Western Europe, we were wondering if we could say more about the longer-term effects on individual birds by it from our tracking data.

And indeed we could. Not only did the majority of tracked geese fly long distances during New Year’s Eve—as compared to previous nights where they usually just sit on a small lake, saving energy and resting during the long dark winter night—but they also foraged up to 10% longer and more during all 12 days after New Year that we have analyzed. In more severe winters the replenishing of energy that they thereby do, might become critical.

Why was it important to study geese for an extended period before and after New Year's Eve/Day?

We could compare what geese usually do at night versus during New Year’s Eve and how their day behavior (e.g. foraging duration) changed from before New Year due to the fireworks night after New Year and if and how long such change lasted.

You found that the birds rested less and flew farther after fireworks exposure. Why are these findings important? Were you surprised that the geese had distinct behavior changes?

Geese spend their winter in Western Europe to escape extreme Arctic winters in their breeding grounds. Still, winters here are maybe not severely cold, but rather dark. As predators are around in the dark, geese can only forage in the light hours. During the night, they usually roost on small lakes or coastal areas to save energy and rest in relative safety. During New Year’s Eve, geese are heavily scared, as the fireworks sounds and flashing lights are unexpected to them and they perceive it as a threat to their life. 

Just flying off in the dark can be dangerous, as the birds might fly into obstacles, but more importantly, flying needs a lot of energy, and during winter this is limiting for them. They cannot forage as long as they want during the next day to replenish, but they are limited by the few light hours available.

What surprised me in our finding was not that the birds were scared or flew off, but for how far some of them moved, up to 311 miles (500 kilometers), which is a distance that they usually only make during migration (well prepared and fattened up). Furthermore, the fact that they had to forage up to 10% more for the complete duration of 12 days after New Year—and maybe longer, but we couldn’t look—was more than I had expected, the aftereffect of the fireworks disturbance is rather strong and long-lasting.

You had a kind of control when the pandemic reduced the amount of fireworks. Why was it important to note that even a small number of fireworks had an impact on goose behavior?

We were curious if less firework activity also had a lower impact on the birds. Did they fly shorter distances or were foraging in the days after less? This was not the case: Two out of four species showed similarly strong flight behavior during the lockdown New Year. So, even 30% of the usual fireworks activity is sufficiently frightening for the animals. This finding is especially important if one wants to discuss how to improve the situation for our wildlife at New Year. Decreasing the activity of customer fireworks by bans does not work. 

Also, understanding the importance of fireworks for people, a complete ban would probably not work. Therefore, we propose that creating quiet areas for wildlife might be a way forward to finding a compromise between people and wildlife during New Year’s. Nationwide regulations that would ban fireworks in and around bird/nature reserve areas would give the animals retreat areas. Outside of these areas, birds would still be disturbed and fly off, but not as far. Also, fireworks could be centralized somewhat in urban areas by organizing fireworks displays and inviting the public to fireworks activities around those sites.

Would you suggest that fireworks affect other bird species in a similar manner?

All pet owners know that none of their animals much favor fireworks—most of them fear it greatly. The same, and maybe even stronger so, holds for wildlife. On nights when it is usually quiet and calm, extreme sounds, flashing lights, and smoke from fireworks is disturbing the rest or nightly foraging activity of nocturnal animals.

Depending on the biology and habitat preferences, different species might react differently. Geese prefer open areas, where hiding is usually not a good idea, so they flee. Other species might hide away during New Year’s Eve, but studies parallel to ours show that they show strongly increased activity in nest boxes (songbird, for example) and/or experience increased heart rates (greylag geese), which again leads to higher energy expenditure during that disturbance night.

How do you hope these findings are used?

We hope that our findings will be used to improve fireworks legislation with actual quantitative findings of their effects on wildlife. We want to provide decision makers with real numbers to support their discussions. As already stated above, we suggest from our findings that retreat areas are necessary for wildlife to escape fireworks disturbance during New Year's Eve, e.g. nationwide regulations regarding nature/bird reserve areas and some centralization of fireworks displays, as well as public fireworks in urban areas away from natural reserves.