Full Moon Nights: Why Wildlife Collision Risk Rises

Late-night drivers tend to think about tiredness, poor visibility and drink drivers. Far fewer realise that the moon itself can add to the danger. A wide-ranging review of collision data now indicates that, on nights with a full moon, the likelihood of hitting an animal rises sharply - by almost half on average.

Why the moon greatly increases the risk of wildlife collisions

More light ought to mean less danger - that is the impression created when a full moon casts its silvery light across the road. However, the figures suggest otherwise. Reviews of police and insurance statistics from several countries reach the same clear conclusion: the number of wildlife collisions rises noticeably on full-moon nights, in some cases by around 46 per cent compared with nights without moonlight.

“On bright full-moon nights, the risk of colliding with an animal is almost half as high again on average.”

The key issue is not that the moon directly causes crashes. Rather, moonlight changes the behaviour of both people and animals. Wildlife including roe deer, deer, wild boar and foxes makes greater use of bright nights to search for food. The animals stay active for longer, cross roads more often and can behave unpredictably.

How a full moon changes wildlife behaviour

Wildlife biologists have observed for years that many species adjust their daily and nocturnal routines to moonlight. Particularly cautious animals benefit from the extra brightness: they can spot predators more easily, find their way faster and venture further from cover.

• Roe deer and deer are more likely to cross open ground and farm tracks on full-moon nights, where roads often cut across their routes.
• Wild boar use the light to look for food in fields and meadows, including areas close to roads.
• Foxes and smaller predators hunt more actively and may follow prey right to the roadside.
• Nocturnal birds, such as owls, are also more active and can contribute to braking or swerving incidents.

The more animals that are moving about, the greater the chance that one will suddenly enter the path of a car. Bright conditions also create a false sense of security. Many motorists feel more alert and underestimate the real level of risk.

Why drivers face particular risks on full-moon nights

Collision research identifies several factors that combine unfavourably during full-moon nights:

• Misleading brightness
  Eyes adapt to the soft moonlight, reducing the contrast between distant and nearby areas. Animals at the roadside can blend into the background until they suddenly “appear” in the headlight beam.

• Slightly higher average speeds
  Studies using driving data show that, on bright nights, many people unconsciously drive a few km/h faster than they would in complete darkness. Those few km/h can often determine both braking distance and the force of an impact.

• Late hours and reduced concentration
  Full moon or otherwise, most people’s ability to react declines between 22:00 and 04:00. A tired driver responds more slowly, especially to sudden obstacles such as wildlife.

• Reflections and shadows
  Roads, roadside marker posts, traffic signs and even wet surfaces reflect moonlight. The eyes must continually adjust between bright surfaces and dark areas. Animals emerging from shadow can easily be missed.

Routes that are especially risky during a full moon

The increased risk is not equally strong everywhere. Certain stretches of road stand out:

• Narrow rural roads running through woodland or alongside fields
• Roads with wildlife-crossing warning signs or known crossing routes
• Areas with rapidly growing wild boar or roe deer populations
• Winding sections where the reach of the main-beam headlights is limited

On these routes, insurers and hunting associations sometimes record considerably more collisions on full-moon nights than on new-moon nights. Anyone who regularly commutes through such areas should at least keep moon phases broadly in mind.

What drivers should do on full-moon nights

The risk may rise, but there is no need to leave the car at home whenever there is a full moon. What matters is how you drive. Road-safety experts recommend several measures that can make a difference.

Adjust your speed and drive ahead

On known wildlife routes during full-moon nights, deliberately reduce your speed - even 10 to 20 km/h less can significantly shorten braking distance. Drive at a pace that allows you to stop at any time within the distance you can see.

As soon as you spot an animal at the roadside, ease off the accelerator, brake in a controlled way if necessary and remain ready to brake. Where there is one animal, others often follow, especially with roe deer and wild boar.

Use main-beam headlights sensibly

Outside built-up areas, use main-beam headlights whenever possible without dazzling approaching drivers. This will usually help you spot wildlife earlier, either through shining eyes or silhouettes at the edge of the road.

Dip the headlights in good time when another vehicle approaches. Dazzled drivers see animals even less well and react later.

React correctly in an emergency

The most important rule is not to make a risky evasive manoeuvre. Many serious crashes happen because drivers swerve to avoid an animal, lose control, and end up hitting a tree or entering oncoming traffic.

Brake firmly, keep a secure grip on the steering wheel and hold your lane. This is usually the safest option, even when impact with the animal cannot be avoided. Modern vehicles are designed to absorb such collisions better than a head-on crash with a tree.

What to do after hitting an animal

If a wildlife collision happens despite all precautions, calm action is essential:

• Switch on the hazard warning lights and put on a high-visibility vest.
• Secure the scene and place a warning triangle at least 100 metres away, and considerably further away on fast roads.
• Inform the police and wait for their instructions.
• Attend to injured people and provide first aid.
• Do not touch dead or injured animals, as there is a risk of injury and infection.

For an insurance claim, you will need collision confirmation, usually issued by the police or a local wildlife manager. Photographs of the vehicle, the surroundings and, where possible, the animal can help when the claim is assessed.

Why the full-moon effect also matters in cities

Few people associate large cities with wild boar or deer. Yet many urban areas are now crossed by foxes, raccoons and, on the outskirts, even wild boar. On bright nights, these animals are bolder, using grass verges, railway embankments and parks as corridors before eventually reaching busy roads.

There is also a psychological factor: many people sleep less well on full-moon nights. Anyone driving to work the next morning after too little sleep reacts more slowly and is more likely to overlook suddenly appearing animals, cyclists or pedestrians.

Preparing for potentially dangerous nights

There is no need to memorise moon phases. A quick check of a weather app or calendar is enough to find out when the next full moon is due. People who regularly travel at night for work - such as care workers, shift workers or long-distance lorry drivers - can use this information deliberately.

Allow a few extra minutes for journeys on these nights, check the headlights before longer trips and clean the windscreen thoroughly. Even a light layer of dirt increases glare and reduces visibility at night.

What research says about the moon and people

Experts have debated for decades how strongly the moon genuinely affects people. Most myths - such as higher crime levels or more births during a full moon - are difficult to support statistically. Wildlife-related road collisions, however, present a fairly clear pattern: more light makes wildlife more active, and greater activity leads to more road crossings.

Importantly, the effect varies according to the region and the local animal population. In heavily wooded areas with large numbers of roe deer, collision figures rise markedly. In open agricultural landscapes with little wildlife, the difference between full moon and new moon is much smaller.

One thing is certain: people who view the moon not as a mystical force but as a straightforward road-safety factor can noticeably reduce their own collision risk. A glance at the sky and a slight lift of the foot from the accelerator can sometimes turn a dangerous full-moon night into nothing more than a quiet journey home.