Modern muskkrat and coypu control

Survey spring 2005

In order to break the extermination cycle, we actually need to be able to catch and exterminate the 10,000 female rats that survive the winter. This would save a great deal of animal suffering and money.

We explored several methods in order to achieve this objective, namely:

• Chasing and catching rats acoustically using ultrasound, for example.

• Attracting rats using various bait and scents.

• Driving the rats out of their nests using a strong jet of water.

In the end, three practical approaches remained:

1) Geophysical detection of the burrows.

2) Thermographic detection of rats.

3) The neutralisation (filling) of the excavated burrows.

Ad 1 The use of a so-called ground radar enables us to detect all the passages and tunnels with a diameter of 10 centimetres or more. The radar can penetrate metres deep into the ground and is especially effective for higher and larger quays and terrain. This method is used primarily where there is a risk to the water defences or a danger of subsidence.

Ad 2 Here we work using an advanced infrared camera, which can localise the nest by means of the heat that they emit. This is possible owing to the high sensitivity of the latest generation of detectors, which can express temperature differences of only 1/10 of one degree Celsius.

Ad 3 Where excavated passages pose a risk to the environment, we have the equipment and material to seal them off from water and rats. By controlling muskrats and coypu using the more effective methods described above, we will not have to kill as many rats in the future. Other animals will not be caught by mistake and the catchersÕ working conditions for the catchers will also improve as a result.