Long‐term monitoring of ocelot densities in Belize

Christopher B Satter,Ben C Augustine,Marcella J Kelly,Claudia Wultsch,Emma E Sanchez,Rebecca J Foster,Bart J Harmsen,Miranda L Davis

doi:10.1002/jwmg.21598

Abstract

ABSTRACTOcelots (Leopardus pardalis) are listed as least concern on the International Union for Conservation of Nature (IUCN) Red list of Threatened Species, yet we lack knowledge on basic demographic parameters across much of the ocelot's geographic range, including population density. We used camera‐trapping methodology and spatially explicit capture‐recapture (SECR) models with sex‐specific detection function parameters to estimate ocelot densities across 7 field sites over 1 to 12 years (from data collected during 2002–2015) in Belize, Central America. Ocelot densities in the broadleaf rainforest sites ranged between 7.2 and 22.7 ocelots/100 km2, whereas density in the pine (Pinus spp.) forest site was 0.9 ocelots/100 km2. Applying an inverse‐variance weighted average over all years for each broadleaf site increased precision and resulted in average density ranging from 8.5 to 13.0 ocelots/100 km2. Males often had larger movement parameter estimates and higher detection probabilities at their activity centers than females. In most years, the sex ratio was not significantly different from 50:50, but the pooled sex ratio estimated using an inverse weighted average over all years indicated a female bias in 1 site, and a male bias in another. We did not detect any population trends as density estimates remained relatively constant over time; however, the power to detect such trends was generally low. Our SECR density estimates were lower but more precise than previous estimates and indicated population stability for ocelots in Belize. © 2018 The Authors. Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

Highlights

Ocelots (Leopardus pardalis) are listed as least concern on the International Union for Conservation of Nature (IUCN) Red list of Threatened Species, yet we lack knowledge on basic demographic parameters across much of the ocelot’s geographic range, including population density
In the Fireburn Reserve, the top model held g0 constant and allowed s to vary by sex and yielded a density estimate of 9.3 ocelots/100 km2
Most previous studies on ocelots have used traditional capturerecapture methods applying the mean maximum distance moved approaches, but few studies have applied spatialcapture recapture methods (Martınez-Hernandez et al 2015, da Rocha et al 2016). This is the first ocelot study to derive population density estimates from large-scale and long-term camera-trapping surveys that ranged over multiple sites and years, and one of only a few to use the spatially explicit capture-recapture (SECR) approach

Summary

Introduction

Ocelots (Leopardus pardalis) are listed as least concern on the International Union for Conservation of Nature (IUCN) Red list of Threatened Species, yet we lack knowledge on basic demographic parameters across much of the ocelot’s geographic range, including population density. Several ocelot studies have reported that social system dynamics between male and female ocelots typically follow that of other felids, with male territories overlapping 1 females (Murray and Gardner 1997, Sunquist and Sunquist 2002, Di Bitetti et al 2006, Dillon and Kelly 2008) and male ocelots potentially using roads or trails where cameras are placed more intensively than females (Royle et al 2013) These differences in space use between sexes are likely to effect g0 and s in a camera trapping context and should be considered explicitly within the models to avoid negatively biased estimates that occur in the presence of un-modeled individual heterogeneity in detection function parameters (Sandell, 1989, Sollmann et al 2011)

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Conclusion