Why researches should be using local traditional knowledge to estimate biodiversity

It is vital now, more than ever to understand the abundance of Amazonian species, as overhunting, deforestation and deliberate burning are huge threats to biodiversity. The harvest rate of wildlife is unprecedently high in tropical regions and overexploitation of the Amazon’s fauna has been particularly severe in recent years. Worryingly, there has been an expansion in subsistence hunting in the Amazon, focused on most of the medium-sized large mammals, reptiles and birds.  

Meat consumption in the Amazon is driven by species availability and local preferences for meat, which are influenced by religious and cultural taboos. Demand from urban bushmeat markets could be driving the increasing exploitation of species.  

Utilising Indigenous knowledge in species richness study

To gather estimates of populations for a wide variety of Amazonian species, including those threatened by hunting, Thais Morcatty, a Brazilian ecologist and BES member, studying at Oxford Brookes University, turned to alternative methods. 

Thais was faced with a common problem. Typically, line transect surveys are used to estimate species abundances and are based on whether you directly encounter an animal. This then allows you to extrapolate these estimates over a whole area to attain population numbers. However, research has already shown that these standard methods are insufficient and likely under-detect terrestrial mammals. Subsequently, Thais tapped into the expert knowledge of local Indigenous hunters to enhance scientific data. 

Thais aimed to collect local estimates of species richness through interviews and compare them against ten years of transect data from 16 sites in the Peruvian and Brazilian Amazon. These sites were part of a cross-organisation consortium involving British, Spanish and Brazilian research groups. Ninety-seven species were included in the analysis, included the heavily hunted howler and woolly monkeys, tapirs, paca and peccaries. 

Indigenous hunters were recruited to identify a ‘cultural consensus’ for species abundance estimates. Asking communities their opinion and utilising local knowledge is crucial as it reflects the biological and cultural diversity of the Amazon biome. This allows the fostering of stewardship by Indigenous people and recognises their voices as the true guardians of tropical forests. 

“Cultural consensus theory assumes that cultural beliefs are learned and shared across people and that there is common understanding amongst people from the same cultural background regarding a topic”, said Morcatty.

Why Indigenous knowledge is invaluable for ecology

Thais and other researchers found a good consensus amongst local people on species abundance for many of the species. Hunters agreed more on abundance estimates for medium to large species, which were easy to spot and hunted frequently. 

Thais commented that “local people are very accurate when they estimate by themselves”.  

For example, high agreement was documented for howler monkeys and tapirs – diurnal, non-elusive and frequently hunted for subsistence. On the contrary, the neotropical otter, an elusive, aquatic species which is not rarely hunted, had a low consensus for its abundance. 

Interestingly, although the researchers found that local estimates and scientific transect calculations were in close agreement with each other for many species, there were some exceptions. Some species had considerably good consensus amongst locals but were rarely detected by the transects. 

The yellow-footed tortoise is adept at camouflage, Thais said, “its carapace colours match perfectly with the litter on the forest ground, making it really difficult to detect during transect sampling.” Nocturnal species such as pacas, tapirs and armadillos are rarely spotted in diurnal surveys. What these species have in common, is that they are popular amongst hunters and are reported by local people during interviews. 

Hunting pressure can be so severe on certain species, that they disappear from transects, such as currasows and spider monkeys. Local people may be the last people to see them and hold valuable information on critically endangered and rare species. 

As a result, local knowledge may be the only way to keep tabs on certain species, so must be incorporated in management strategies otherwise we risk not detecting severely threatened species. Science is not enough. Indigenous people simply know more than researchers, as the Amazon is their home. 

These findings demonstrate that local knowledge is precise in estimating species abundance in tropical forests. Thais explains, “these findings indicate that, overall, the results we found in around 10 years of transect monitoring are very similar to those obtained through traditional ecological knowledge for the same period”. 

The future of monitoring in the amazon

Based on Thais’ findings, Indigenous citizen science can be an accurate and low-cost tool for monitoring populations in tropical forests and approximating their conservation status.  

In the future, monitoring must transcend the combined transect-cultural consensus approach to assess the abundances of rare and elusive Amazonian species. These developments will be particularly useful in unsampled areas of the Amazon, where we do not yet know the species composition and have not engaged with people who live there. 

As demonstrated by Thais, partnerships among scientists and local people are the best way to achieve wildlife conservation. Local knowledge could accelerate the establishment of protected areas and creation of critical management strategies. This is especially pertinent in the Amazon, where both species and Indigenous cultures are threatened by anthropogenic activities such as forest clearing, dams, mining and oil extraction. A holistic redirection of ecology to local knowledge may better help protect one of Earth’s biodiverse forests, such as the Amazon. 

Conservation as a discipline should be advocating for the continued incorporation of traditional ecological knowledge into research. Future researchers can follow in Thais’ footsteps and look above and beyond the science to ensure that first and foremost, the local culture of Indigenous and riverine peoples in the Amazon is preserved. 

Stay tuned to the BES journals for updates on this work!

*****

Sicily Fiennes is a PhD student in Extinction Studies at the University of Leeds.

This article first appeared in The Niche, March 2020. The Niche is the British Ecological Society’s quarterly membership magazine. If you’re not a member but would like to subscribe to The Niche, join us today.