The dog on your walk as a detector for nature: in Germany, owners and their pets learned to find invasive plants with 75% accuracy

What happened

On 4 November 2026 the journal PLOS One published a study that science news services reported on 6 November. German researchers showed that ordinary dog owners and their pets can learn to find invasive plants in the wild. The trained teams' average detection rate was 75%. The work was led by Annegret Grimm-Seyfarth of the Helmholtz Centre for Environmental Research (UFZ).

What invasive species are

Invasive, or non-native, species are plants and animals that humans have brought to new areas, where they push out native species. They are considered one of the main causes of biodiversity loss worldwide. In Europe examples include giant hogweed, Japanese knotweed, common ragweed and Himalayan balsam.

Why finding them early matters

Controlling invasive plants is expensive and slow. Once a species has spread over a wide area, it is almost impossible to get rid of. It is far cheaper to find the first plants in a new place and remove them before they spread. But early detection is the weakest link: individual young plants are easy to miss in the grass.

A dog's nose instead of human eyes

Dogs can tell smells apart far better than people. They are already used to search for explosives, drugs and people under rubble, and in conservation to find rare animals, their droppings and plants. These are usually professional dogs working with specialists. The German researchers wanted to know whether ordinary pet dogs with volunteer owners could do the job.

The IGAMon-Dog project

The study was part of the IGAMon-Dog pilot project, in which private dog owners are trained alongside their dogs to become volunteer wildlife detection teams. The partners are the UFZ, the Independent Institute for Environmental Issues (UfU) and the association Wildlife Detection Dogs. The project has already won second place in the Saxony-Anhalt environmental awards.

How the training worked

Between 2021 and 2023 the researchers trained 31 dogs and their owners. The dogs learned to recognise the scent of three invasive plant species. Training ended with a field test: each team had to find the target plants in a real landscape rather than on a training ground.

The test results

Twelve teams reached the field test and 11 passed it. The average detection success was 75%. Not every team made it to the end: some dropped out during the long training for various reasons. The researchers analysed in detail what success depended on and drew up recommendations for future projects.

Himalayan balsam

One of the target plants was Himalayan balsam, a tall plant with pink flowers that comes from the Himalayas. In Europe it quickly takes over river and stream banks, crowding out native plants. In autumn it dies back, leaving bare banks that are more easily washed away. Its seeds are flung several metres, so one plant soon produces new stands.

A rare project

The authors stress how unusual their work is. They say it seems to be one of the rare volunteer-based wildlife detection dog projects aimed specifically at finding invasive species in the field rather than in experiments. “The results show that it is generally possible to train volunteer teams to detect invasive alien plants,” they write.

A walk as a contribution to science

The researchers particularly like the idea itself. It is a chance, they say, to turn something people already love doing, spending time outdoors with their dogs, into a meaningful contribution to protecting biodiversity. With the right training, everyday walks could become an additional resource for detecting invasive plants early.

More than a good nose

At the same time, the researchers warn that enthusiasm is not enough. “Enthusiasm is a great starting point, but reliable monitoring requires more than a good nose,” they say. Teams need carefully designed training and continuing support from experts. Otherwise the results will be unreliable and the effort wasted.

The researchers' recommendations

From the project the researchers drew up recommendations for similar programmes. The main points:

1. Select volunteers carefully, choosing people ready for long training.
2. Make sure teams are coordinated and supported by specialists.
3. Build up training gradually and check skills regularly.
4. Carry out first field deployments under expert supervision.
5. Keep volunteers and dogs motivated throughout the project.

Dogs versus people

The idea is not new. In a 2010 study in the US, dogs found an invasive knapweed more accurately than people: 81% against 59%. Dogs are especially good where plants are still small or hidden in dense grass. People search with their eyes, dogs with their noses, and a plant's scent gives it away even when it cannot be seen.

How a dog learns a scent

Training a detection dog is a lot like a game. First the dog sniffs a sample and gets a treat or a toy when it goes to it. Then the sample is hidden in harder and harder places, and later the dog moves on to living plants outdoors. It learns to indicate a find with a signal, such as sitting or lying down next to it.

Which dogs are suitable

Dogs of many breeds and crossbreeds are suited to scent work. What matters is an interest in searching, motivation from food or play and the ability to concentrate. Many spaniels, retrievers, shepherd dogs and terriers take to it quickly. Age and health count too: fieldwork takes stamina.

Benefits for the dogs

Searching is good for dogs too. It works the brain, relieves boredom and stress, and strengthens the bond with the owner. Many trainers recommend scent work for dogs that are restless at home or struggle to be left alone. Even simple games of finding treats around the house bring a dog real benefits.

Plants that are dangerous to dogs

Some invasive plants are dangerous for dogs too. Giant hogweed sap causes severe skin burns in sunlight in both people and animals. Ragweed triggers allergies. So in detection work it is important that the dog indicates a find without touching the plant and that owners know which species are dangerous.

Avoiding hogweed burns

Dog owners who walk along rivers and on wasteland should know some simple rules:

1. Learn what giant hogweed looks like.
2. Do not let your dog run into stands of tall umbel-flowered plants.
3. If your dog touches the sap, wash its coat and skin with soap and water.
4. Keep your dog in the shade for the next day.
5. Take it to the vet if redness or blisters appear.

Getting started with scent work

You can try scent work without joining a research project. Many towns have clubs and trainers offering scent work, where dogs find smells simply for the fun of it. Classes suit dogs of any age, including older dogs and those for whom active dog sports are too demanding. It is best to start with simple tasks and short sessions.

Why dogs smell so well

Dogs have many times more scent receptors in their noses than people, and the part of the brain that processes smells is far more developed. A dog can also split the air it breathes in: part goes to the lungs and part to the olfactory area. That is why it can pick out the scent of a single plant among many others.

Citizen science

The study is an example of citizen science, in which members of the public help researchers gather data. Volunteers already count birds and butterflies, photograph plants and report sightings through apps. Detection dogs could become a new tool, particularly for early detection of species that are hard to spot.

How the results could help

If such teams worked in different regions, conservation agencies could learn more quickly when invasive plants appear in new places. They could then be removed before they spread. The authors believe this would save money and help protect native plants and animals.

What comes next

The researchers hope their recommendations will help similar projects start in other regions and countries. The key conditions are professional support and good training for the teams. The project showed that ordinary dog owners are willing to spend time on this work if they can see the point.

What this means for Europe

Invasive plants are a shared European problem, and the EU requires countries to monitor their spread. The German experience shows that millions of dog owners could become helpers for conservation agencies. If training programmes became more widely available, owner-and-dog teams could appear in other countries too, including in the UK.

When to see a vet

Take your dog to the vet if, after a walk through undergrowth, redness, swelling, blisters or sores appear on its skin, especially on the muzzle and belly. Get urgent help if your dog has chewed an unknown plant and starts vomiting, drooling, becomes weak or has fits. Before starting detection work it is worth having its joints and eyes checked.