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23.03.98

ULTRALIGHT VS. VOLE: 1 to 0

This charming little animal above is a vole, usually found in meadows. The ultralight, generally seen as a leisure aircraft, comes to help farmers.

Because the vole, in the permanent meadows, might simply gnaw up to 60 % of the meadow. Fighting against it is therefore a must in the regions ensuring the milk supply, such as the Doubs, the Vosges, the Lorraine, both Savoies, the Pyrénnées. In the west par of France, where meadows are usually artificial - understand: cultivated and sowed - that problem does not exist.

It can be identified by what is often confused to be molehills, lives underground and digs numerous galleries. It additionnally has the ability to reproduce itself at high speed: from one single couple, one gets 144 voles within 9 months ! The evaluation of voles' populations is hence cardinal for farmers.

This animal is relatively unknown, as well as the reasons why a population grows in a given place, whereas a neighbour field will have none.

We then met Régis Defaut, who works for the regional federation of defense groupments against the agricultural pests (FRDEC) in the Doubs department.

This company, partly working on the Ministery of Agriculture budgets, has the responsibility of evaluation, training and fighting against all mammalians, insects and bacteries attacking plants.

Originally set up to ensure and control mandatory collective fights - for instance, against the Colorado beetle -, the scope of the FRDEC was broadened to include all plants' pests. These groupments are communal, then federated by department.

Régis and his teammate are responsible for 4 departments. For the Doubs alone, this means visiting each year more than 500 communes, and some 180'000 hectares...

The usual method is to drive in each commune with a car (15 to 20'000 km), with a full time staff of 2, during 1 and 1/2 month to 2 months, to check on the ground the voles' populations, and give a 0 to 4 note to each commune. A 0 rating indicates that only a few volehills were found, a 3 that alert stage has been exceeded, with already important damages.

The sight from the ground does of course not ensure the full reliability of reports, which is important: when the results are published in the press, farmers need between 6 to 12 months to react and accordingly treat the meadows. Taking into account the vole's speed of reproduction, getting an alert in due time is a priority, before the meadow has been invaded and destroyed.

Other means of looking at the voles' populations were tested as well. For instance, aerial photography from a radio-controlled model plane: that worked, but proved to be relatively complicated and expensive. Or statistical methods based on satellite infra-red pictures: there, populations are well seen... once they invaded the meadows, and that it is therefore too late to act.

Then last year, Régis made a test with an helicopter. That allowed to certify that, seen from the sky at low altitude, the precision of evaluation was at least twice better than the one from the ground. However, with the inconvenience of very high costs.

This year, Régis decided to try with an ultralight. After one hour to test if that kind of aerial work was feasible, a contract was signed for the whole evaluation campaign at attractive financial conditions with ULM Loisirs Services. So, during a few days, Régis flew all day long the voles' populations, commune by commune, with Cédric Fornerod as pilot in a Clipper (trike).

From the pilot's point of view, that kind of flight is especially constraignant and strictly restricted to professional pilots, the flight altitude being generally between 30 and 70 meters above the ground. This implies a very high level of concentration at any time, so as to avoid electric lines and other ground obstacles. He confided that taking into account 3 to 6 hours of flight per day, that very high stress could hardly exceed 3 days a week.

But success is there: in one single day of flight, the territory that would require a whole week by car is covered. With a precision in the results at least twice better than from the ground. And, during that time, the other member of the team may attend other businesses. As a summary, a 1 to 10 ratio for the ultralight, bringing a large time gain, hence financially very interesting for the FRDEC.

Thanks to the ultralight, the FRDEC is now able to inform faster, with a far better reliability, and at lower costs. The farmers will hence be able to act faster. We bet that other federations in other departments will follow that exemple.

As a bonus, this campaign had two additional positive effects for Cédric: firstly, he now knows how to treat his landing strip, that is as well invaded by voles. And, secondly, that campaign made of Régis a new ultralight adept, as he wishes to use it as well during his leisure time.

Contacts:
FRDEC, Rue de Belfort 191, Immeuble Orion, F-25000 Besançon
ULM Services Loisirs, La Vrine, F-25520 Goux les Usiers. See as well the ultralight landing, and the school.
Phone: +33 3 81 39 26 04, fax +33 3 81 39 26 05