Tuesday, April 05, 2005

A 'Biological' Fence?

An 'old wive's tale' still practised in many country gardens uses a variation of biological scent marking to deter intruders. While the shelves of up-market garden centres may contain 'lion's dung' pellets, the carrot patches of rural gardens were given of dose of a home grown deterrent. The men of the family, (we're told it doesn't work with females) would urinate around the perimeter, to stop badgers digging up the carrots.

We have been given permission by its author to quote a BSc pilot study which used this principle, to determine if ' non-kin' badger scent, could be used in a similar way, i.e to deter other badgers not of the same social group.

Badgers are territorial, scent marking 'their' patch with a latrine or urine spray. They will fiercely defend this area and sometimes kill other badgers who try to enter. The trigger appears from the study to be the communal 'scent' from their excretions.

The researcher introduced faecal material to a badger latrine from a non-kin sett latrine several miles away. Adult badgers refused to use it and created a new latrine area. Only the 3 small cubs ventured near. Similar experiences with sett bedding, had been seen by researcher in a previous study. When a ball of new grass bedding was artificially scented, the badgers ignored it for 24 hours but if scented with non-kin badger scent they ignored it for at least 7 days, with the dominant male eventualy kicking it away from the sett entrance.

The researcher's conclusion was that non-kin badger scent was a powerful deterrent to incoming badgers not of the same social group.

"The scent of non-kin faeces is sufficient to deter a badger from entering its own latrine area, even if only temporarily, suggests it may be possible to exclude badgers from a particular area by using scent" .

The author saw possibilities for the use of their own scent in the translocation of badgers away from construction sites, and from undermining buildings. But the primary interest of this site is the transmission of tuberculosis, and on that subject the researcher concluded:

"As badgers have been very strongly linked with the spread of Bovine tuberculosis, the implications for this (research) are obvious. If this effect could be reproduced chemically and commercially, it may be possible to segregate cows and badgers thus minimising the spread of Tb between the species. Goman et al's research (1984 - Distinctive badger social group scent) could be expanded in the hope of isolating the particular chemical(s) which, in sufficient quantities could be used by farmers as a deterrent."

The weak link in all strategies concerning the eradication of Tb from badgers is their ancestral home. The sett has acquired a Grade 1 listing, and is allowed to remain intact - a time bomb to reinfect incoming badgers. Artificial scent marking may have a place here, as it may in the protection of farm buildings.

Our grateful thanks for the paper.

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