Eco-tourism can generate, besides employment and improved local economics, important revenue to support nature conservation. However, this kind of tourism, when uncontrolled, can also lead to habitat degradation and adverse impacts on the species we want to protect. Constant exposure of the animals to tourists and the stress thereof can lead to undesirable effects in the animals, such as impaired growth, reproduction, and immunity.
These chronic stress effects have been recognised in wild populations of a variety of species in eco-tourism areas.
Therefore, when the core business of tourism organisations is to organise close encounters between endangered primate species and tourists, much care should be taken to avoid such chronic stress. In the case of Bornean orangutans (Pongo pygmaeus morio), which are an endangered species according the IUCN Red List of Threatened Species, there are no signs of chronic stress. At least not in the Lower Kinabatangan Wildlife Sanctuary in Sabah, Malaysia, where eco-tourism trekkings are conducted by Red Ape Encounters*, a community-owned and –operated programme. This was revealed in a study led by anthropologist Michael P. Muehlenbein, and recently published in PLoS ONE. The researchers measured levels of glucocorticoid metabolite in — easily to obtain — fecal samples of the orangutans. This fecal glucocorticoid metabolite is a good indicator of the levels of cortisol, the stress hormone, in the animal’s blood after a stressful event. The study shows that fecal glucocorticoid metabolite levels were significantly elevated in samples collected the day after the tourists visited the sanctuary. This is indicative of elevated cortisol production on visitation day. As the glucocorticoid metabolite levels return to normal after the visits, and are not permanently raised, the scientists conclude that these orangutans are not chronically stressed. Mr. Muehlenbein can’t say yet what makes the wild orangutans of Borneo deal with stress differently than other species in other locations, but the effects of stress on wildlife populations are likely context dependent. So, the way Red Ape Encounters conduct their tours could be less stressful for the orangutans, than other, more frequent and intense, tours organised in other locations.
*Eco-tourism guidelines used by Red Ape Encounters include limiting visitation groups to seven people for no more than one hour; excluding sick tourists; maintaining a 10-meter minimum distance; and requiring appropriate behavior. The company hosts about 250 tourists per year, with most of the visitor activity centered on the two wild habituated orangutans used in the study: Jenny, an adult approximately 32 years old, and her 11-year-old son Etin.