Friday, July 17, 2009

The Scarecrow

Whilst wandering around a pet shop up on the Gold Coast last week I stumbled across a cool repellent device: Contech's Scarecrow.

It's essentially a motion-based sprinkler system that (according to the manufacturer) detects animal movement in a 110 degree arc in front of it and then shots out a 2-3 second burst of water from an integrated sprinkler. The combined noise, movement and water spray is supposed to startle the animal and scare it away. The range is only about 10 metres, but the concept is pretty exciting.

I should probably note that I have also subsequently found that at least one other similar product from another manufacturer.

It cost $129 to buy, but I have seen it on Australian websites for between $108 and $129.

I was so interested in this because, the failure of many of the repellents and deterrents we (and others) have tried to date such as gun shot noises, flashing lights, other predator odours is partly I believe because of the co-evolution aspect where the animals learn that the repellent isn't actually a threat so quickly learn to ignore them.

I have been playing with the idea of an automated Sentry system based on a paintball gun mounted to a detection system after stumbling across The Sentry Project a few months ago, but this approach was foiled by the fact that the Patriot act prevents the export of the software out of the U.S.A. plus there was also operational problems with potential injury to animals, and technically how to get the movement recognition to work at night. Finally, with a maximum range of 50 metres (the effective range of a paintball gun) and requiring a laptop, lighting system and paintball gun for every sentry they would be quite expensive, highly prone to theft, and therefore of fairly limited application.

The sprinkler system though is a much more viable system (and less problem with potential eye injury to animals) for smaller areas requiring protection.

So, I bought one, tested my baggage limit in bringing it back to Tassie, and handed it over to Mick Statham and his team to trial in their wallaby enclosure at Mt Pleasant, Launceston.

Trial Day 1 (Thursday 16th July, 2009)

The Scarecrow was set up in the wallaby enclosure with a pile of juicy carrots placed about 2 or 3 metres in front of it. The spot had been fed with carrots the previous day, so the wallabies (both Bennetts and Rufous) already knew there was food there and had cleaned the initial carrots away. I should say the enclosure is about 0.8ha, with a I think 10-15 bennetts and rufous wallabies in it. They have plenty of other food in the enclosure (just look at the grass in the videos) and are fairly free roaming.

Initial results were very positive. Even before Mick had left the site, both a rufous and bennetts wallaby had approach the carrot pile and been promptly scared off by the Scarecrow. Have a look at the video below:

However it was only hours before the effectiveness began to dissipate :

... and ultimately the scarecrow's success was pretty short lived: by 5pm that night footage showed several bennetts wallabies happily munching on the carrot pile as the sprinkler went off over their heads. Later footage showed both rufous and bennetts wallabies demolishing the carrots as well, chasing each other and seemingly genuinely unconcerned by the scarecrow (see video below which is two x 1 minute videos spliced together)

So, day 1 wasn't the smashing success we hoped for, but all is not lost, it could be that because we'd set the sprinkler up high to maximise its range, that the wallabies learnt to run under it and then they could eat in peace. Once one wallaby did this, the others would quickly have followed. So Plan B is to lower the water so it shoots directly at the wallabies ... stay tuned ...

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