FRANKFURT – At the side of a railway track on the outskirts of Frankfurt, Cocker Spaniel Monte is enthusiastically sniffing the ground, his long furry ears flopping around his nose.

When he finds what he is looking for, he obediently stops, sits and is delighted to receive a treat from his trainer.

Monte is one of six dogs being trained by German rail company Deutsche Bahn to identify the presence of protected species in potential construction sites.

The dogs “can take us directly to where the animals are” and can work all year round in any weather conditions, says Jens Bergmann, director of infrastructure projects at Deutsche Bahn’s network subsidiary.

Finya, Fenna, Storm, Eskil, Monte and Whisper use their keen sense of smell to sniff out snakes, toads, bats, lizards and other creatures whose presence could hamper the progress of construction works.

“The law requires us to identify the possible presence of protected species,” explains Bergmann.

“We then either have to protect them on site or find a new habitat for them.”

Without the dogs, this process can take specialists up to a year. But having them on board reduces the timeframe to less than two months, and is much less invasive.

It also avoids “the unpleasant surprise of finding animals when the machines are already there”, says Kathleen Spittel-Schnell, one of the dog trainers.

“This can lead to additional delays in the project or, worse still, to a complete halt in construction,” says Spittel-Schnell, who is also employed by the rail group as a protected species specialist.

– Lizards and snakes –

Electric car mogul Elon Musk knows this all too well — last year, Tesla was forced to suspend construction work on its planned factory outside Berlin over concerns about protected lizards and snakes.

Deutsche Bahn has already relocated some 12,000 endangered animals since 2010.

As part of their training, the dogs are presented with a large metal container with holes in it, a bit like a bottle bank. Behind one of the holes is the scent of an endangered species.

Golden Retriever Whisper tickles the holes with his muzzle before plunging his nose into one of them.

Monte is just one year old but already knows what to do if he finds an protected animal: don’t put your paws or your muzzle on it. Just sit and wait for your treat.

While dogs have been used as a monitoring technique for decades, “it is only recently that they have garnered serious attention by ecologists from all over the world”, according to a study published in March in the British journal Methods in Ecology and Evolution.

Dogs are already being used to detect wildlife in the United States, as well as to identify endangered species or items such as ivory passing illegally through customs.