DOI: 10.5061/dryad.905qfttms
title: Congruence of local ecological knowledge (LEK)-based methods and line-transect surveys in estimating wildlife abundance in Amazonian forests

description: 1) Effective estimation of wildlife population abundance is an important
 component of population monitoring, and ultimately essential for the
 development of conservation actions. Diurnal line transect surveys are one
 of the most applied methods for abundance estimations. Local ecological
 knowledge (LEK) is empirically acquired through the observation of
 ecological processes by local people. LEK-based methods have only been
 recognized as valid scientific methods for surveying fauna abundance in
 the last three decades. However, the agreement between both methods has
 not been extensively analysed. 2) We compared concomitant abundance data
 for 91 wild species (mammals, birds and tortoises) from diurnal line
 transects (9,221 km of trails) and a LEK-based method (291 structured
 interviews) at 18 sites in Central and Western Amazonia. We used
 biological and socioecological factors to assess the agreements and
 divergences between abundance indices obtained from both methods. 3) We
 found a significant agreement of population abundance indices for diurnal
 and game species. This relationship was also positive regardless of
 species sociality (solitary or social), body size and locomotion mode
 (terrestrial and arboreal); and of sampled forest type (upland and flooded
 forests). Conversely, we did not find significant abundance covariances
 for nocturnal and non-game species. Despite the general agreement between
 methods, line transects were not effective at surveying many species
 occurring in the area, with 40.2% and 39.8% of all species being rarely
 and never detected in at least one of the survey sites. On the other hand,
 these species were widely reported by local informants to occur at
 intermediate to high abundances. 4) Although LEK-based methods have been
 long neglected by ecologists, our comparative study demonstrated their
 effectiveness for estimating vertebrate abundance of a wide diversity of
 taxa and forest environments. This can be used simultaneously with line
 transects surveys to calibrate abundance estimates and record species that
 are rarely sighted during surveys on foot, but that are often observed by
 local people during their daily extractive activities. Thus, the
 combination of local and scientific knowledge is a potential tool to
 improve our knowledge of tropical forest species and foster the
 development of effective strategies to meet biodiversity conservation
 goals. --
description: This study
 was conducted in 18 sites located in the Brazilian (n=9) and the Peruvian
 (n=9) Amazon. These include eight specific sites in upland forest, four in
 flooded forest and six in both upland forest and flooded (Fig. 1). Eight
 locations are within indigenous villages, nine are in non-indigenous
 riverine villages, and one site has no human settlement (Supplementary
 Material, Table 1). The non-indigenous riverine villages are located in
 Sustainable Use Protected Areas, which are a legally recognized category
 of protected area in which traditional people partake in decision-making
 on natural resource use and management. Hunting remains an important
 subsistence activity for the residents living within these
 areas. <i>Data
 collection</i> Between 2011 and 2017, we surveyed
 the abundance of a set of species through line transects, and through
 interviews with local people from 17 different indigenous and
 non-indigenous riverine villages. All villages were settled in or near the
 sites where transects were surveyed, and local people use these sites for
 different purposes (hunting, harvesting of forest products, etc.);
 therefore, each village offered information about at least one
 correspondent site. Sixteen villages informed LEK about a single
 correspondent site, and 1 village informed LEK for 2 correspondent sites.
 Interviews and line transects within each study area were conducted in a
 mean lapse time of 8.6 months, ranging from 0 to 24 months.
 <i>Line transects</i> We estimated
 the population abundance of each species from direct diurnal sightings
 conducted on 31 line transects, with a total surveyed distance of 9,221 km
 (ranging from 42 km to 2,687 km surveyed per site; mean= 512 Km, SD= 707)
 (Supplementary material, Table 1). Each transect was randomly positioned
 in all study areas and transects were opened prior to the surveys. Two
 observers (at least one of them was a local monitor) walked the trails
 between 6:00 h and 15:00 h at an average speed of 1.5 km/h. When a group
 of animals was encountered, the number of individuals and species was
 recorded. From the collected data, we calculated the sighting rates
 (individuals/km, calculated as the total number of individuals observed
 divided by the total effort in km travelled on any given transect during
 all seasons), which were used as our abundance index since higher
 abundance increases species detections (e.g. Paim et al., 2019). The value
 of zero was assigned to species whose occurrence is confirmed in the area
 but that were not detected on any transect sampled near that
 village. <i>Local Ecological
 Knowledge</i> We interviewed 291
 local people from the sampled villages (average interviewees per village
 =16.16, SD=6.62) using a snowball sampling technique (Bailey, 1994)
 through the indication by each interviewee of another local expert on
 fauna. The interviewees' ages ranged between 16 to 75 years old
 (average = 37.75; SD=13.29). We conducted interviews individually to
 collect the interviewee perception of the abundance through LEK-based
 methods of each species that occur in the area in which the interviewee
 lives. Interviews did not require local translators as both the
 interviewers and the interviewee, including those from indigenous
 territories, were fluent in Portuguese or Spanish. All researchers
 conducting the interviews were already working in each site and had built
 relationships of trust in the communities.  Data were collected through
 structured interviews with an illustrated checklist, which provided colour
 plates of species expected in each study area. During each interview we
 asked the local vernacular name for each species illustration, often
 corresponding to the species common nomenclature in Portuguese or Spanish.
 For each species, we asked the interviewee to estimate their abundance on
 a Likert scale; 0 (when the species was “absent”), 1 (low abundance), 2
 (medium abundance) and 3 (high abundance) (Van Holt et al., 2010; Van Holt
 et al., 2016). The value assigned by each interviewee for each species was
 considered as our abundance index for the LEK-based method. The value of
 zero was assigned only to species whose occurrence is expected for the
 area by previous studies but was mentioned as absent by a specific
 interviewee. We validated the consistency of the responses through a
 cultural consensus analysis (Borgatti and Halgin 2011), which consists in
 a multivariate test based on the degree of similarity between respondents’
 answers. In this case, respondents showed a personal consensus higher than
 0.6 (indicating a high consensus) regarding the abundance indices of each
 species population.
description: Article title associated with this data: <b>Congruence of
 local ecological knowledge (LEK)-based methods and line-transect surveys
 in estimating wildlife abundance in Amazonian forests. In Methods in
 Ecology and Evolution journal.</b> The
 bioecological characteristics of the species can be found in the
 supplementary material of the article.<br> The abundance information
 database presented here is complete.