It is surprising how widely distributed humans are. Even supposedly remote, untouched locations are, on closer inspection, influenced directly or indirectly by human presence. I first realised this during my time in the Peruvian Amazon, when we would occasionally encounter fishermen and travellers travelling downstream from deep within the forest, however distant from human civilisation I thought we were. This isn’t without consequence on wildlife. It is practically impossible to find un-hunted areas, and this has probably been the case for several millennia, as shown by a growing body of palaeoecological evidence from Africa, Asia and South America.

As such, I was not entirely surprised when Sarah Papworth, who led the seminar, told us that prey animals react in an analogous way to humans as they do to predators, in the distance they keep between themselves and the intruder and the reaction time. Of these prey animals, monkeys are a culturally important one to Amazonian peoples. They are hunted for food, kept as pets and in more recent time valued for science and tourism by individuals seeking to observe natural behaviour. Consequently it is important to be able to distinguish natural behaviour from behaviours induced by human presence, in order to better conserve species and avoid systematic bias during observational studies.

Sarah recorded woolly monkey behaviour and noted that although they reliably took action to decrease their visibility, they displayed a threat-sensitive response to hunters, gatherers and researchers. Some researchers have attributed this to the possibility that primates haven’t yet had the time to fully evolve a response to humans as predators, but given the time-scale of human presence in tropical forests, this is unlikely. It is more probable that given, the density of humans in forests and their variety of activities, it would be costly to respond to every sighting, so primates have evolved to recognise behaviours and evaluate threats.

An interesting point was made regarding threat evaluation. How would primates in natural parks distinguish hunters and poachers from park rangers carrying weapons? Are they able to learn and respond accordingly? How do you minimise stress generated from the conservation effort itself? These are just some of the questions raised during the seminar, which will certainly lead to more interesting research in this field.

Such research finds direct application in understanding how primates respond to predation risk, but also in designing better observational studies which account for modified behaviour.