Amsterdam’s water board is about to try a dirty, or at least stinky, trick on deer that have been wandering into city roads and gardens from the dune areas that are their normal realm.
The plan is to mount small dispensers that look and work much like household air fresheners on posts along the paths they’ve been following off the reservation. The devices emit a smell that resembles lion manure and fire. It’s apparently already been used successfully to keep rabbits, foxes and wild boars off railway lines.
The key ingredient in the smell is tupoleum, developed by a German chemist to keep deer away from farms growing Christmas trees. It appears that the fact that Dutch deer haven’t any experience of lions is not important: a Dutch university professor told newspapers “All animals fear predators and fire. Even if they smell them for the first time, the message is ‘Get out of here!'”