Ecological tourism has no effect on the presence of large mammals in the Amazon, according to a study that for the first time compares the biological diversity of ecotourism（生态旅游） zones with that of protected areas. Furthermore, it can help to protect the biodiversity of areas that are not officially protected yet are vital in the ecological framework. Since the UN began to promote ecological tourism at the end of the 1980's as a way of protecting the environment without resorting to its economic exploitation, the debate as to whether ecotourism is really beneficial has remained alive.

Aiming to answer such questions, two Spanish researchers spent four months in the middle of the Amazon to assess the presence of large mammals in Bonanza, a private estate used for ecotourism within the Manu Biosphere Reserve. The results of their study show that not only is ecotourism harmless to the biological richness of the area but it could even have a positive effect on the biodiversity of surrounding areas.

The study by Salvador Salvador (University of Gerona) and Miguel Clavero, (Doñana Biological Station-CSIC), in collaboration with Renata Leite from Duke University's Center for Tropical Conservation, has been published in the Mammalian Biology journal.

In their analysis of the Bonanza estate, the researchers found 41 species of large mammal out of the 48 species that have been documented in the whole reserve. According to Salvador, "we could not find any way in which the richness of species has been affected. No species sensitive to the presence of humans was lacking and although we were unable to calculate population density, species like the tapir（貘） (Tapirus terrestris) or the huangana (a local way of referring to another type of wild boar, the Tayassu peccary) were abundant, even compared to virgin forest areas.

As the study lasted for four months, the researchers were also able to compare the presence of fauna（动物群） during the dry and wet seasons.

When we talk about ecotourism, Salvador warned that "we have to understand the difference because a [photographic] safari in Kenia is not the same as what we studied in the Amazon rainforest." The importance of the study lies in the fact that never before has the biodiversity of ecotourism zones been contrasted with that of protected areas, at least in the Amazon.

"The size of the ecotourism areas bears little significance in relation to the size of the extensive Amazon's ecosystem and yet some species had been found to be affected," said Salvador. One of them was the giant otter（水獭） (Pteronura brasiliensis), which is native to the Amazon and considered endangered by the International Union for Conservation of Nature. The expert pointed out that "these were some cases but no real comparison had been made until our study." Inadequate ecotourism practices that negatively affected the otter were mainly linked to river transport. For example, the boats used to transport tourists would come too close to the dens of the otters.

After four months of field work and interviews with the locals, the results show that Bonanza has "at least 85% of species." The expert added that "the species from pristine（原始的） areas that were not found in Bonanza are likely to appear there, given that despite their rarity they are not considered particularly sensitive to human presence."