Tourist photographs are a cheap and effective way to survey wildlife

Source: Science Daily

Tourists on safari can provide wildlife monitoring data comparable to traditional surveying methods, suggests new research. The researchers analyzed 25,000 photographs from 26 tour groups to survey the population densities of five top predators (lions, leopards, cheetahs, spotted hyenas, and wild dogs) in northern Botswana, making it one of the first studies to use tourist photographic data for this purpose.

https://www.sciencedaily.com/releases/2019/07/190722182132.htm