DOI: 10.5061/dryad.gtht76hp7
title: Quantifying the relationship between prey density, livestock and illegal killing of leopards

description: Many large mammalian carnivores are facing population declines due to
 illegal killing (e.g., shooting) and habitat modification (e.g., livestock
 farming). Illegal killing occurs cryptically and hence is difficult to
 detect. However, reducing illegal killing requires a solid understanding
 of its magnitude and underlying drivers, while accounting for the
 imperfect detection of illegal killing events. Despite the importance of
 illegal killing of large carnivores in comparison with other causes of
 mortality, its relationship with potential drivers such as livestock
 density and wild prey abundance is rarely described. Using
 ranger-collected data (2007-2019) of leopard killing events and data on
 covariates (livestock density, wild prey abundance, road length, protected
 area size, elevation) across Iran, we applied a single-visit N-mixture
 model to jointly model variation in detection probability and expected
 annualized number of leopard killing events. Over the study period, we
 estimated 428 leopard mortalities (95% CI 184–1014), which was 45% larger
 than the observed number. Expected intensity of leopard killing was
 positively related to protected area size, livestock density and wild prey
 abundance. Detection of leopard killing was higher in areas with more
 developed road networks. Synthesis and applications Ranger based
 monitoring data on poaching of carnivores are cost-effective, but
 traditional analysis does not take into account imperfect detection. We
 show that innovative statistics (single-visit N-mixture modeling) can
 reliably quantify poaching events and address their drivers, at large
 geographical scales. We used the example of the Persian leopard across
 Iran, but our approach is also applicable to understand killing dynamics
 of other species. Results suggest that a high frequency of leopard killing
 is likely to occur in areas with &gt; 100 livestock per km2 and
 &gt; 450 individuals of wild prey per km2. This highlights the need
 for improved management of livestock grazing and effective measures around
 high-risk protected areas to mitigate human-leopard conflict and reduce
 killing of leopards.
description: Our dataset composed of three parts: 1. The
 leopard illegal killing events' data (2007-2019) were collected by
 rangers across Iran (provided by Iranian Department of
 Environment).  2. The wild prey abundance data were
 provided by Iran's Department of Environment (DoE). The wild prey
 abundance are being collected annually (November-December) by skilled
 rangers within a regular monitoring program, which is being managed by the
 DoE across the country. 3. The site covariates data
 were obtained from the following sources: 3.1.
 Elevation (mean elevation from a 30-m resolution digital elevation model,
 was obtained from the NASA Shuttle Radar Topography Mission
 (https://search.earthdata.nasa.gov) 3.2. Road length
 (we obtained this from http://download.geofabrik.de/236 and https://extract.bbbike.org/, 2018)  3.3. Protected area (Iran's Department of Environment)  3.4. Human density (we obtained this from Gridded Population of the World v.4 at a 1-km spatial resolution from the Socioeconomic Data and Application Center  (http://sedac.ciesin.columbia.edu/data/se, 2015) 3.5. Livestock densities (data on livestock (i.e., cattle, sheep and goats) were derived from the Food and Agriculture Organization, FAO (http://www.fao.org; 2005) All these data were extracted and assigned per grid cell (20*20 km2) across Iran using ArcGIS version 10.7.1 (ESRI USA). The data were analysed within a single-visit N-mixture modelling framework (Royle 2004 Biometrics; Sólymos et al. 2012 <em>Environmetrics</em>; Kéry and Royle 2021 AHMbook) in 'unmarked' R package (Fiske & Chandler 2011) in R software version 3.3.6 (R Core Team 2020).