According to an article published in Nature by a professor from the Université de Sherbrooke
Trophy hunting endangers the future of bighorn sheep
Sherbrooke, le 10 décembre 2003 – The hunting of male bighorn sheep in the Ram Mountain area of Alberta is endangering the future of this major herd and has already had a negative impact on the genetic characteristics of the species.”
This is the conclusion drawn by Marco Festa-Bianchet, a professor in the Department of Biology of the Université de Sherbrooke (Quebec), in an article published by the renowned scientific review Nature, which he coauthored with colleagues from the United States and the United Kingdom. The researcher claims that: “Our study is the first to demonstrate the impact of artificial selection on a wild population by taking into account data gathered since 1971 from almost every member of the herd.”
The study demonstrates that the current policy of trophy hunting runs counter to the phenomenon of natural selection, which favours bighorn sheep that have long horns and thus are more able to protect females in heat than those with shorter horns. “Hunters practise a form of artificial selection that progressively and very rapidly eliminates genes promoting the growth of long horns. Worse still, the genetic characteristics of bighorn males are also associated with other hereditary features, such as the size of the individual and possibly its strength, health, etc. This means that this species loses its best sires, and we very quickly come to appreciate the negative impact this has on the other characteristics of the population,” explains Marco Festa-Bianchet.
At the present time, any Alberta resident may purchase a permit to hunt the male bighorn sheep and harvest any ram whose horns have a greater than 4/5 curl. Because these horns are seen as a trophy, a male with long horns may be slaughtered once it reaches the age of four, whereas its horns will not allow it to successfully pursue a female before it reaches about seven years of age. This means that the bighorn sheep has a fairly short life expectancy and, thus, limited chances of passing on its genetic heritage. Since the rams with short horns are of no interest to the trophy hunter, these animals meet with little competition during the rutting season and the species is becoming more and more dominated by males with shorter, less sturdy horns.
Thirty-two years of scientific investigation have already demonstrated that the genetic component determining horn length has been modified: the males have horns that are genetically shorter than those of their forebears. “Our study stresses the importance of taking into account genetics and evolutionary ecology when dealing with wildlife management and the conservation of species,” explains Marco Festa-Bianchet, who is currently on a lecture tour in Australia.
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Gilles Pelloille, Communications Officer
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