Study

Evaluating the effectiveness of human–orangutan conflict mitigation strategies in Sumatra

  • Published source details Campbell-Smith G., Sembiring R. & Linkie M. (2012) Evaluating the effectiveness of human–orangutan conflict mitigation strategies in Sumatra. Journal of Applied Ecology, 49, 367-375

Actions

This study is summarised as evidence for the following.

Action Category

Use nets to keep primates out of fruit trees

Action Link
Primate Conservation

Humans chase primates using random loud noise

Action Link
Primate Conservation
  1. Use nets to keep primates out of fruit trees

    A controlled, replicated, before-and-after trial in 2007-2009 in an agro-forest system in Batang Serangan region, north Sumatra, Indonesia found that in areas where farmers used tree nets, crop-raiding by orangutans Pongo abelii was reduced. In areas where farmers used no mitigation technique, the frequency of crop-raiding events did not change. Crop yield increased from 69 kg to 176 kg (61% increase) after trials on farms where farmers used tree nets (n=10 farms) and decreased from 64 kg to 47 kg (27% decrease) on farms where no mitigation technique was trialled (n=15 farms). In addition, interviews with 50 farmers (of which 50% participated in the trials) showed that attitudes towards orangutan management had changed after the study. The proportion of farmers who wanted orangutans removed from their farms decreased from 58% before the study to 28% after the study. However, all farmers stopped using nets as a mitigation technique five months after the study. Barrier nets of 5 x 5 cm2 mesh stitching nylon rope were placed to partially or entirely cover the canopy of 14 separate jengkol Archidendron pauciflorum trees.

  2. Humans chase primates using random loud noise

    A controlled, replicated, before-and-after trial in 2007-2009 in an agro-forest system in Batang Serangan region, north Sumatra, Indonesia found that in areas where farmers used noise deterrents and tree nets, crop-raiding by orangutans Pongo abelii was reduced, compared to areas where no mitigation was used. Orangutan feeding time on crops was lower on farms that used noise deterrents and tree nets (69 min, n=25) than on farms that did not (81 min, n=25). In addition, interviews with 50 farmers (of which 50% participated in the trials) showed that attitudes towards orangutan management had changed after the study. The proportion of farmers who wanted orangutans removed from their farms decreased from 58% before the study to 28% after the study. Forty per cent of farmers continued to use noise deterrents as a mitigation technique five months after the study. Hand-held firecracker cannons made out of bamboo and tin filled with calcium carbide to produce noise, and hand-held bamboo drums were used on 25 farms.

Output references

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