Local News(Taitung District Agricultural Research and Extension Station)

Eco-Friendly Monkey Prevention for Orchards—Tree Armor

2016-05-03

So as to reduce fruit damage and profit losses caused by Formosan macaques in way that is ecologically friendly, the Taitung District Agricultural Research and Extension Station (TTDARES) of the Council of Agriculture, Executive Yuan has developed a weapon that neither harms wild animals nor negatively impacts the environment—a mesh tree cover, which basically serves as full-body armor for trees. This technology was developed after studies were done on macaque behavior and habits, and it has proven to prevent the serious damage caused by macaques. The tree cover protects tree fruit well, and it only takes two people to easily put the covers in place. Here is how it works: 1) For the first year, only trees along the edge of the orchard where macaques enter need to be covered. 2) During the second year, if the macaques seem to not be dismayed by the covers, gradually add covers to trees beginning from the edges toward the center of the orchard. 3) During and after the third year, when the macaques become familiar with the covers again and go further into the orchard, be sure to cover all trees that produce the most and best fruit. This method has the following five features/merits: a) The covers are easily fastened in place, durable, and safe; b) they work well at keeping macaques and other invaders out; c) by using the gradual, year-by-year method of introducing the covers to the orchard, the annual costs are low and the return on investment is good; d) the covers protect the trees and fruit in a number of ways; and e) there are no negative effects on the trees, fruit, or environment. These covers reduce grower losses caused by macaques and also have a number of other benefits, currently making them one of the most feasible and best forms of macaque prevention in Taiwan. However, since macaques are clever, observant, and quick to learn, the best way to control them is through a diversity of means. Thus, a combination of obstruction, deterrence, and even hunting/catching must be considered while taking season, geography, and observed habits into consideration.

Mesh tree covers do not harm wild animals or the ecology. 　　 How Formosan macaques react to mesh tree covers (images taken via sensor-activated infrared cameras). ～ Macaques are able to loiter in orchards and eat at their leisure when mesh tree covers are not in use.

　 Once the macaques are no longer afraid of the covers, a few will try to get at fruit inside the covers. They are only able to get at fruit hanging low and right next to the cover (images taken via sensor-activated infrared cameras), and they leave small holes in the covers as a result of biting. Thus, they are unable to severely damage the covers or get inside, in turn protecting the fruit well. 　 Once the macaques are no longer afraid of the covers, a few will try to get at fruit inside the covers. They are only able to get at fruit hanging low and right next to the cover (images taken via sensor-activated infrared cameras), and they leave small holes in the covers as a result of biting. Thus, they are unable to severely damage the covers or get inside, in turn protecting the fruit well.

During the first year. only trees located at the edges of the orchard, where monkeys enter, are covered. This offers a high degree of damage prevention. 　 Tree mesh covers being used on orange trees such as the one on the left offer significant protection, maintaining a high level of yield and fruit quality. In contrast, all of the fruit on the uncovered tree to the right has been damaged.