Rows of lemon trees will be trialled as a deterrent for elephants wandering into rice fields, in a bid to reduce conflict between humans and the giant mammals.

The work is in Lampung Province, Sumatra, on the border of Way Kambas National Park in Indonesia, and forms part of a broader approach by an international group of organisations to help the Sumatran rhinoceros, the Sumatran tiger, the sun bear, the Sunda pangolin and the Asian elephant.

As part of its 100th birthday celebrations, Taronga Zoo in Sydney is working with several organisations including Yayasan Badak Indonesia (the Rhino Foundation of Indonesia) and wildlife trade monitoring network TRAFFIC, raising $500,000 for conservation programs in Sumatra, Indonesia.

These species of rhino, tiger and pangolin are all listed as critically endangered on the IUCN Red List of Threatened Species, meaning they’re considered to face “an extremely high risk of extinction in the wild”.

The Asian elephant is listed as endangered, and the sun bear as vulnerable.

Aside from keeping animals out of crops, the projects will focus on veterinary support, community work (in eco-tourism), and demand reduction—one example of this is the Wildlife Witness smartphone app, created by TRAFFIC and Taronga Zoo, to encourage tourists and locals to easily report wildlife trade with a photo in the exact location it takes place.