Deer prudence: technologies for better wildlife protection

It’s a wretched moment for any animal lover. A wild creature runs out in front of your car. There is no time to slow down, stop or swerve.

Over one million animals and ten million birds are killed on Britain's roads every year, according to the National Deer Collisions Project. And yet, historically, almost nothing has been done to even attempt to deal with this problem, short of shooting large numbers of deer before they can get onto the roads and damage our cars. Some call this sustainable population management. Others call it conservation!

In Cannock Chase, Staffordshire, some real wildlife conservationists have been trying to do something to actually protect animals. This is a place where fast main roads cut through 26 square miles of woodland, farmland and heathland, and where large numbers of fallow deer are killed by vehicles every year. After a count in 2016 found around 170 fallow deer dead on roads around the Chase, countryside rangers working for the local authority decided to take action.

Funding was secured from local councillors, the British Deer Society and the Area of Outstanding Natural Beauty (AONB), and with it, virtual sonic fence devices were bought from Austrian company ITPE Solutions. The devices were placed along a one-km stretch of the A513 near Shugborough, 25 metres apart. This is a perilous spot where fallow deer herds regularly move from woodland on the Chase side of the road to feed on pasture land in the Shugborough Estate on the other.

“It was particularly bad last September and October when male deer crossed from the Shugborough side to the Chase for the rutting season,” says Rob Taylor, a ranger with Staffordshire County Council.

The idea was to try and install an early warning system that would give deer and other animals crossing the road longer to react to approaching vehicles. Optical and acoustic sensors, attached to posts by the roadside, pick up the sudden increase in light from a car headlight, trigger an alarm, which then emits a strobe LED light towards the woodland where the deer are coming from, and a high-pitched sonar signal between 4kHz and 8kHz. The theory is that any deer, or indeed any other animal in the vicinity of the device as a car comes past will hear the sound, see the light and be scared away from the road, returning to cross when the way is clear.

The lights are blue and yellow, colours that the deer see well. Earlier attempts to keep deer off the road in the Chase used red reflectors, which were supposed to resemble the colour of wolves’ eyes. Not that any deer in these parts has ever seen a wolf. Wolves were trapped and hunted to extinction in England by the end of the 15th century.

Initially the Cannock Chase project was a success, with a 60 per cent reduction in night-time deer casualties recorded in the first year. In particular rangers noticed that fewer male deer were being hit by vehicles during the rut.

However, when the scheme was expanded in October 2019, to run along a stretch of the Penkridge Bank Road, near to the Birches Valley Forest centre, it was with a new and improved version of the sonic fence technology – a version that is now also being used in Austria, Latvia and Italy, even as far afield as the USA, Australia and Tasmania with varying degrees of success.

Andreas Schalk, executive director of ITPE Solutions, explains that in Austria several thousand devices are already in place along highways, national roads and sections of railway. This is part of a research project being conducted by the Austrian rail, highway authorities and the Ministry for Transport Innovation and Technology “On the highways where there is a steady flow of traffic, the device will be triggered, not by the vehicle, but by the animal, through a thermal sensor,” Schalk says. “On the railways the devices emit a louder sound and have a greater range than the devices used on the roads. The latest sensors also pick up the speed of the approaching vehicle, making them useable in daylight. At some sites, more than 50 per cent of the accidents happen in the day.”

These devices have been deployed with great success near Borzano in northern Italy, and along the mountain road that runs between Italy and Austria Schalk estimates a 62-70 per cent reduction in accidents involving red and roe deer.

The Latvian government has ordered around 1000 devices for deployment next year around an 8km stretch of highway west of Riga, with another 30km stretch of highway to follow, should the initial project prove successful.

The sonic fences worked less well in Utah in the USA, on a section of road that was particularly wide, 24 metres, and fast, with a 75mph (120km/h) speed limit. “At night time, cars went even faster and there wasn’t enough time for the animals to get off the road,” Schalk says.

'We are trying to get the animal to perceive a threat when a vehicle is coming towards it.'

Things are working rather better along a 6km stretch of the C214 road in Tasmania, between the River Arthur and Marrawah settlements not far from the north-west coast. In these parts, the island’s most iconic animal, the Tasmanian devil, is not affected by the horrific contagious cancer that had decimated devil numbers over the last two decades. There is however, a problem with vehicles travelling quickly along unlit roads at night, when nocturnal devils are scouring the area for food. In some places, devil numbers are so low that just one or two breeding females killed on the roads could threaten genetic diversity and therefore the animal’s continued chances of local survival.

Conservationists from the government-backed Save the Tasmanian Devil Programme have noticed a 50 per cent decline in road deaths (wallabies and quolls as well as devils) since the virtual fences were installed in 2015, and 75 per cent in some of the most dangerous crossing areas.

The devices are now being used in eight other sites in Tasmania and also on mainland Australia to warn kangaroos of approaching danger, predominantly in Queensland, but also at one site near Lysterfield in Victoria.

This sonic fence technology is still relatively new, however, and remains a work in progress. The Cannock Chase project showed up a few issues.

“The main problem was that the original devices were attached to the posts and people just stole them, probably thinking that they were speed cameras,” Rob Taylor says. He explains that the project has since appeared in local newspapers and on TV and one hundred deer safety signs have been deployed roadside, around the Chase, to warn drivers of what is going on.

The sonic devices being used on this year’s Cannock Chase project have sensors embedded into the posts, which makes them almost impossible to steal. Both Taylor and Jochen Langbein, a UK-based wildlife and ecology consultant who worked on the project, would like to see a wider range of noises and sounds emitted, so that the deer don’t get used to just the one sound. “Deer tend to use the same tracks to cross again and again,” says Langbein. “But they might use up to 30 different places within a 1km stretch.”

Taylor adds: “When we first installed the devices, I noticed that one place, on the A513 where the deer had been crossing regularly, had so many hoof prints it looked like a bike track. I placed a device there and went back to check a few months’ later; deer were now crossing a few hundred yards away, in between the devices.”

Schalk says evidence from Austria shows that animals do not assimilate to the sound. “We are trying to get the animal to perceive a threat when a vehicle is coming, not deter them from crossing altogether,” he says, adding that the sound only needs to be loud enough and that a variety of sounds is not necessary.

There’s a simple reason for this difference of opinion. The most common species of deer in Austria, is the roe deer, which tends to move around in ones and twos, or at most, in small groups. The fallow deer in Cannock Chase are herd animals. “They tend to run blindly, herd members following the animal in front and all following the lead deer,” Langbein says.

Taylor adds: “Other than the lead few animals, the fallow deer are not reacting to the sound and light, so they’re still at risk.”

The majority of deer killed on UK roads are roe and muntjac, and Langbein would like to see the Cannock Chase sonic devices placed along roads where these two animals are at risk, and speed limits reduced in known collision hotspots. Taylor thinks roadside hedges and verges need to be maintained more regularly, as they are in Europe, so that drivers can see any animals more clearly when they emerge onto the road. Taylor also recommends more research into how the sonic device might be adapted for use with herding animals: in the UK that’s red and sika deer as well as fallow.

Schalk is currently trialling a wireless network of devices on a stretch of railways outside Graz that might solve some of these problems. The network uses a gateway, in advance of the first device, which triggers all the devices when a train passes, giving animals up ahead, more time to get to safety. “We’re currently testing to see how stable the network is with electromagnetic interference given off by trains,” he says.

Langbein thinks that more research is needed into how animals interact with the devices in the wild, and on deer behaviour in general. “At the moment we rely on limited data gathered from animals killed on the road,” he says.

The most obvious way of monitoring deer behaviour, of course, would be through tagging and following individual animals – something that is done around the world, albeit usually with endangered species. Langbein explains that this is not allowed in the UK, though, because a percentage of deer are culled every year for human consumption, and tranquilisers are banned by food standards and health and safety requirements – more economically motivated conservation policy.

In places like Austria, Latvia, Australia and Tasmania, the authorities are willing to invest in technology for conservation purposes. In the UK the authorities are reluctant to get involved.

I contacted Defra, the Environment Agency, Network Rail, the Wildlife Trusts and WWF UK for comments about the roadside devices. None were willing to offer a view. A Highways England spokesperson said: “We are always open to new technologies and innovations to help reduce the number of animals harmed on our network and to help keep road users safe, and we are interested in the potential of the devices used in other countries.”

There are signs that things could be changing, albeit very slightly and slowly. Langbein says that Highways England is trying to get innovation funding to run a project using the more advanced versions of the sonic fence technology. Last year, the same organisation unveiled a wildlife bridge over the Knutsford-Bowdon bypass in Cheshire.

There are a few more of these around the UK, but many more in the Netherlands, France Germany and increasingly in the United States and Canada. A ten-lane wildlife corridor, the world’s largest, is currently being designed on the freeway just outside Los Angeles, along which 300,000 vehicles travel every day. The corridor will connect different parts of the Santa Monica Mountain chain and will help animals travel across wider areas to find food and mates, without crossing the dangerous road.

Wildlife protection projects are expensive however, and if more of them are to appear on the UK’s roads, we’ll require a lot more political will from our leaders.