Why does human-elephant conflict (HEC) occur?
- Elephant habitats are often fragmented, and encroached upon by agricultural fields containing crops. This leads to HEC when elephants raid fields for tasty crops, and when elephants travel through the fields whilst moving on their established trails between habitats, or en-route to waterholes or feeding areas. In addition, their established trails are now impacted by roads and railways. Some researchers contend that HEC is as old as agriculture [in Africa (Bell 1987; Naughton-Treves 1999)].
- " In parts of western Uganda early in the 20th century, high elephant populations prevented agriculture altogether" (GDA 1924; Osmaston 1959)
- "Forest dwellers in pre-colonial northern Gabon lived at the“brink of starvation”, because their food supply was regularly devastated by elephants" (Barnes 1996:68)
- Today, human-elephant conflict is a major cause of death and injury for both elephants and humans. In the case of crop-raiding, as you can imagine, farmers and villagers will fight back, killing the elephants in order to prevent crop-loss, and the elephants will attempt to defend themselves. In the case of elephants traversing fields, villagers may come upon them unaware, thus startling the elephants, who will then perceive the humans as a threat and defend themselves. Elephants are also often killed by trains as they attempt to cross the railway lines that cut through their trails.
How to stop HEC?
- One way to prevent HEC is to automatically detect the elephants and alert villagers, or even train-drivers! Elephant detection systems can be positioned both at the interfaces between elephant habitats and agricultural fields - thus providing an early-warning to villagers if elephants launch crop-raids - and along known elephant paths - thus providing villagers with a warning that elephants are in the area, and reducing the likelihood of them coming upon elephants unaware and startling or scaring them.
Summary of automated elephant-detection methods:
General components of an elephant detection system utilizing vision- and acoustic-based techniques, including outcomes post-detection
1. Extracting elephant vocalizations from the local soundscape
- Elephants regularly emit low-frequency (10-30Hz) rumbles for communication; these travel several km in distance.
- Drawbacks: elephants may remain silent, or may learn to remain silent after having been detected after making noise, difficulty in extracting from a 'busy' soundscape, natural variability in elephant calls
2. Vision-based techniques
- Elephants are the largest land animal and have a easily identifiable appearance
- These, in my opinion, are the most promising methods of elephant-detection in terms of accuracy and cost. Although only thermal imaging would be useful at night! In general these techniques would rely on pole mounted camera, which would be activated when movement was detected using a PIR sensor. The real-time imagery would be sent using RF or cellular networks to village-based computers for analysis. If there was a high-probability of detection, villagers would be notified via SMS. There are several vision-based techniques available: [* motion analysis is a possibility]
- a. Multi-curve matching: "photo identification system based on the shape comparison of the nicks characterizing the elephants’ears" http://www.researchgate.net/profile/Enver_Sangineto/publication/222127859_Identifying_elephant_photos_by_multi-curve_matching/links/0c960531d9ddfd4cad000000.pdf …