Using spatial patterns in illegal wildlife uses to reveal connections between subsistence hunting and trade

Abstract

Although most often considered independently, subsistence hunting, domestic trade, and international trade as components of illegal wildlife use (IWU) may be spatially correlated. Understanding how and where subsistence and commercial uses may co-occur has important implications for the design and implementation of effective conservation actions. We analyzed patterns in the joint geographical distribution of illegal commercial and subsistence use of multiple wildlife species in Venezuela and evaluated whether available data were sufficient to provide accurate estimates of the magnitude, scope, and detectability of IWU. We compiled records of illegal subsistence hunting and trade from several sources and fitted a random-forest classification model to predict the spatial distribution of IWUs. From 1969 to 2014, 404 species and 8,340,921 specimens were involved in IWU, for a mean extraction rate of 185,354 individuals/year. Birds were the most speciose group involved (248 spp.), but reptiles had the highest extraction rates (126,414 individuals/year vs. 3,133 individuals/year for birds). Eighty-eight percent of international trade records spatially overlapped with domestic trade, especially in the north and along the coast but also in western inland areas. The distribution of domestic trade was broadly distributed along roads, suggesting that domestic trade does not depend on large markets in cities. Seventeen percent of domestic trade records overlapped with subsistence hunting, but the spatial distribution of this overlap covered a much larger area than between commercial uses. Domestic trade seems to respond to demand from rural more than urban communities. Our approach will be useful for understanding how IWU works at national scales in other parts of the world.

Assessing Africa‐Wide Pangolin Exploitation by Scaling Local Data

“…Instead, collating local‐scale hunting studies may provide more accurate estimates of the number of animals hunted and relevant information to aid conservation efforts, complementing seizures data (Sánchez‐Mercado et al . ).…”

“…Law enforcement and seizures data have been used to quantify exploitation of threatened species; however, these data suffer from detection biases and underestimation (Gavin et al 2010). Instead, collating localscale hunting studies may provide more accurate estimates of the number of animals hunted and relevant information to aid conservation efforts, complementing seizures data (Sánchez-Mercado et al 2016).…”

How to deal with ground truthing affected by human‐induced habitat change?: Identifying high‐quality habitats for the Critically Endangered Red Siskin

“…Our approach has proven useful for identifying key habitats for a threatened and poorly sampled species and also to monitor temporal and spatial trends in vegetation transformation within these habitats. In the case of the Red Siskin, this approach is only the first step toward identifying suitable habitat for reintroduction, which should be refined with additional research focused on breeding and feeding ecology, seasonal movements, and the spatial distribution of poaching risk (e.g., Sánchez‐Mercado, Asmussen, Rodríguez‐Clark, Rodríguez, & Jedrzejewski, ).…”

Multiplex networks reveal geographic constraints on illicit wildlife trafficking

“…1). Importantly, traffickers are frequently characterized as opportunistic actors (Brashares et al 2011;Oldfield 2003;Sánchez et al 2016). The trafficking of each species constitutes a network (plex), and several networks form a connected hyper-network (multiplex) due to the ability of traffickers to switch between species, and smuggle or sell multiple species simultaneously.…”

“…This biodiversity is also expressed in the cultural gradient that persists across the country (Aristizabal Giraldo 2000; Loh and Harmon 2005). Relatively high levels of wildlife diversity, spatial heterogeneity, human mobility, cultural diversity and economic disparity are factors contributing to the prevalence of wildlife trade (Brashares et al 2011;Lindsey et al 2013;Sánchez et al 2016). Wildlife trafficking in Colombia is one of the most pressing conservation concerns for many groups of species, in particular for reptiles and birds (Rodriguez et al 2008).…”