Browsing by Autor "Mario S. Di Bitetti"

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Comparing capture-recapture, mark-resight, and spatial mark-resight models for estimating puma densities via camera traps
(Oxford University Press, 2014) Lindsey N. Rich; Marcella J. Kelly; Rahel Sollmann; Andrew J. Noss; Leonardo Maffei; Rosario Arispe; Agustín Paviolo; Carlos De Angelo; Yamil E. Di Blanco; Mario S. Di Bitetti
Camera-trapping surveys, in combination with traditional capture-recapture or spatially explicit capture-recapture techniques, have become popular for estimating the density of individually identifiable carnivores. When only a portion of the population is uniquely identifiable, traditional and spatial mark-resight models provide a viable alternative. We reanalyzed a data set that used photographic capture-recapture methods to estimate the densities of pumas (Puma concolor) across 3 study sites in Belize, Argentina, and Bolivia using newer, more-advanced modeling including spatial and nonspatial mark-resight techniques. Additionally, we assessed how photo identification influenced density estimates by comparing estimates based on capture histories constructed by 3 independent investigators. We estimated the abundances of pumas using mark-resight models in program MARK and then estimated densities ad hoc. We also estimated densities directly using spatial mark-resight models implemented in a Bayesian framework. Puma densities did not vary substantially among observers but estimates generated from the 3 statistical techniques did differ. Density estimates (pumas/100 km2) from spatial mark-resight models were lower (0.22–7.92) and had increased precision compared to those from nonspatial capture-recapture (0.50–19.35) and mark-resight techniques (0.54–14.70). Our study is the 1st to estimate the density of a population of carnivores, where only a subset of the individuals are naturally marked, using camera-trapping surveys in combination with spatial mark-resight models. The development of spatial mark-resight and spatially explicit capture-recapture techniques creates the potential for using a single camera-trapping array to estimate the density of multiple, sympatric carnivores, including both partially marked and uniquely marked species.
Estimating Puma Densities from Camera Trapping across Three Study Sites: Bolivia, Argentina, and Belize
(Oxford University Press, 2008) Marcella J. Kelly; Andrew J. Noss; Mario S. Di Bitetti; Leonardo Maffei; Rosario Arispe; Agustín Paviolo; Carlos De Angelo; Yamil E. Di Blanco
Estimates of abundance are extremely valuable for species conservation, yet determining abundance for elusive, wide-ranging, carnivores is difficult. We estimated density of pumas using remote cameras across study sites in Bolivia, Argentina, and Belize. We used obvious and subtle markings to identify individual pumas in photographs and conducted double-blind identifications to examine the degree of agreement among investigators. Average agreement on identification between pairs of investigators was nearly 80.0% and 3-way agreement was 72.9%. Identification of pumas as different individuals was uncommon (7.8% pairwise, 0.69% 3-way disagreement) with the remainder described as unidentifiable. Densities of pumas varied consistently from site to site regardless of investigator. Bolivian pumas moved the shortest distances between camera stations and Argentinean pumas the longest, but distances among cameras and area covered by surveys varied among sites. We applied a correction factor to the Bolivian data to account for the small area surveyed and found that, averaged across investigator, Bolivia had significantly more pumas per 100 km2 (mean ± SD; 6.80 ± 1.5) than Belize (3.42 ± 1.3) or Argentina (0.67 ± 0.2). Numbers of pumas in Argentina match those of low-density North American sites, and those for Belize are consistent with the Pantanal and high-density North American sites. Densities of pumas can be reliably estimated with remote cameras for these sites, and our work presents the 1st density estimates for Central America and for forested environments in South America.
Small Wild Felids of South America: A Review of Studies, Conservation Threats, and Research Needs
(2023) Nicolás Galvéz; José Infante-Varela; Tadeu Gomes de Oliveira; Juan Camilo Cepeda-Duque; Lester Alexander Fox-Rosales; Darío Moreira‐Arce; Juan Carlos Huaranca; Mario S. Di Bitetti; Paula Cruz; Flávia Pereira Tirelli