Category: Cars and roads

Koalas, cars and the urban setting

Koalas are often killed by cars in towns where the speed limits are much lower as well as out of town on higher speed roads.

One issue for koalas coping with roads in an urban area, is that there is more happening to distract the koala and the person driving the car.  The koala has to process a variety of stimuli such as electric lights, dogs barking, children noises, other machinery or traffic, humans and animals walking about and probably an extremely fragmented home range.  A car approaching, even at only 60kph is probably just a part of the cacophony around them.

In these situations koalas often simply step onto the road directly in front of a car apparently without seeing it was there at all.  This is not because of poor eyesight, but because they cannot separate and deal with all the stimuli.  Think of it like very young children playing and how unsafe that is near the road because we know a young child is likely to become so focused on play they will not see a car approaching.  In a similar fashion koalas just focus on where the tree they need to get to is, rather than what may be in between them and this destination.

Koalas spend most of their time sleeping and digesting. When they move they are focused on where they are going, not on what is around them.
Koalas spend most of their time sleeping and digesting. When they move they are focused on where they are going, not on what is around them.

Koalas are often seen walking along a road (rather than across), or they are reported to simply stop and sit in the middle of a road and watch a car approach and stop in front of them.  Observing koalas, it would appear that their flight response is often very low as they don’t have a ‘sense of danger’.  This is discussed in the article on dealing with cars in more detail.

When the flight response is elicited in a koala they commonly give a leap in the opposite direction or any random direction and begin to run without checking to see if they have chosen a safe direction.  They will then attempt to run to anything that looks like a ‘tree’ structure.  In other words, something they can climb.  This makes sense because their brain tells them that getting up high is the safe response.  Once a koala rushes up a structure in fright it tends to then determine to stay there until well after dark.

Hence we see koalas sitting high up telegraph poles, on fences, or even veranda posts seemingly unwilling to move.  The more stressed that koala becomes, the less likely it is to come down.

This is the typical koala response:

  1. ignore everything
  2. react without thinking and get up high
  3. stay very still until late at night when all is very quiet

Roundabouts provide another level of complexity that is nearly impossible for a koala to cope with.  All the koala sees is their food tree on the other side and they attempt to move towards it.

It is up to us as drivers to take more notice of wildlife on the roads, as the wildlife are not going to learn our rules.

Koala dealing with cars

Koalas need to do fast calculations when going near our roads, as they try adapt to the modern world.
Koalas need to do fast calculations when going near our roads.

Once a koala is down on the ground and encounters a road, things really become seriously dangerous and complicated for them.  What is a road to a koala?

A bitumen road (or even a gravel road) is a foreign surface for an animal that was already not doing so well on the ground. The koala may hear a car approaching, but what does the koala brain do with this information?

I will talk about their hearing and mechanical noises in another post, but for the purpose of this post it is fair to say that hearing a car and knowing you are in its path becomes a more complex calculation than you might think.  As humans we know that a road means the path a car will travel along, the rules it will travel by (eg speed limits and which side of the road, depending on the direction being travelled), and we know what a collision with a car will mean.

Because of these facts, we can use executive thinking skills to quite quickly decide if it safe to cross a particular road.  We know it takes some mathematical calculation ability, and we know that a person affected by alcohol is unlikely to calculate this correctly either as a pedestrian crossing a road, or as a driver encountering a pedestrian suddenly.

We also know that many scientific studies have assisted governments to determine safe driving speeds on different roads by calculating the time it would take to stop a vehicle in an urgent situation according to the environment and the road conditions.

The only safe place for the koala is high in a tree as we see Enigma in this image.
The only safe place for the koala is high in a tree.

Let’s get back to the koala who is down on the ground, with their front-facing eyes and their mind on getting to the next safe food tree.  That koala does not have the kind of sense of danger a prey animal is wired to use when moving about, and so they focus on where they are going.

To the koala, a car approaching, when it is say 50 metres away, even if they can see and hear it, is unlikely to register as a threat to them.  They are unlikely at this point to even consider that it is on a course that will cross their path, even though they are on a road.  If we consider the speed the car is moving at, then a car moving at 100kph that is 50 metres away will be on top of the koala in less than 2 seconds.  There is no chance for the koala to calculate this and be out of the way in time.

Typical NSW country road - dual carriage with soft edges and lots of vegetation.
Typical NSW country road – dual carriage with soft edges and lots of vegetation.

Let’s add another layer of complexity.  The image above shows an intersection literally on a boundary of Koala Gardens. I want to examine a few important features as they are common roadside features our koalas deal with all over the NSW East Coast.

Firstly the amount of vegetation very close to the roadside is typical and an important consideration for the koala.  If a koala was in the vegetation on either the front right or on the opposite side of the road the driver would not see it as the vegetation is far taller than a koala.  This will also mean that the koala cannot see any car until it emerges from the vegetation at which time the koala is literally on the road.  The speed limit here is 80kph, so if the koala emerges and a car is 50 metres away, there is 2.25 seconds for the koala to get out of the way.

To the brain of a koala, an approaching car that went right past when it was sitting beside the road is no different, in terms of danger, than the approaching car when the koala has moved forward slightly and is now on the road.

Vandalised sign alerting drivers to be on the lookout for koalas.
Vandalised sign alerting drivers to be on the lookout for koalas.

There are no lights on country roads, so at night, unless the koala looks directly at an oncoming car, they are very difficult for the driver to see.  There are often thick fogs at night on these country roads which reduces vision for both the driver and the koala.  This is why we have road signs advising of known native wildlife, asking drivers to take extra care.

We have seen no evidence to suggest that koalas learn about road safety, or that they teach it to their young.

Finally we are not seeing enough evidence that people truly care about our wildlife.  This roadside sign is typical of the kind of vandalism we often see here, but shows a lack of empathy and understanding of how desperate the koala situation is.