scholarly journals Leopard Panthera pardus fusca Density in the Seasonally Dry, Subtropical Forest in the Bhabhar of Terai Arc, Nepal

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Kanchan Thapa ◽  
Rinjan Shrestha ◽  
Jhamak Karki ◽  
Gokarna Jung Thapa ◽  
Naresh Subedi ◽  
...  
Keyword(s):  
Winter Season ◽  
Population Monitoring ◽  
Panthera Pardus ◽  
Density Estimates ◽  
Seasonally Dry ◽  
Abundance Estimates ◽  
Capture Recapture ◽  
Modelling Techniques ◽  
Wildlife Reserve

We estimated leopard (Panthera pardus fusca) abundance and density in the Bhabhar physiographic region in Parsa Wildlife Reserve, Nepal. The camera trap grid, covering sampling area of 289 km2 with 88 locations, accumulated 1,342 trap nights in 64 days in the winter season of 2008-2009 and photographed 19 individual leopards. Using models incorporating heterogeneity, we estimated 28 (±SE 6.07) and 29.58 (±SE 10.44) leopards in Programs CAPTURE and MARK. Density estimates via 1/2 MMDM methods were 5.61 (±SE 1.30) and 5.93 (±SE 2.15) leopards per 100 km2 using abundance estimates from CAPTURE and MARK, respectively. Spatially explicit capture recapture (SECR) models resulted in lower density estimates, 3.78 (±SE 0.85) and 3.48 (±SE 0.83) leopards per 100 km2, in likelihood based program DENSITY and Bayesian based program SPACECAP, respectively. The 1/2 MMDM methods have been known to provide much higher density estimates than SECR modelling techniques. However, our SECR models resulted in high leopard density comparable to areas considered better habitat in Nepal indicating a potentially dense population compared to other sites. We provide the first density estimates for leopards in the Bhabhar and a baseline for long term population monitoring of leopards in Parsa Wildlife Reserve and across the Terai Arc.

scholarly journals First estimation of Eurasian lynx (Lynx lynx) abundance and density using digital cameras and capture–recapture techniques in a German national park

2012 ◽  
Vol 35 (2) ◽  
pp. 197-207 ◽  
Author(s):  
K. Weingarth ◽  
◽  
C. Heibl ◽  
F. Knauer ◽  
F. Zimmermann ◽  
...  
Keyword(s):  
National Park ◽  
Large Scale ◽  
Lynx Lynx ◽  
Digital Cameras ◽  
The European Union ◽  
Eurasian Lynx ◽  
Habitat Directive ◽  
Abundance Estimates ◽  
Capture Recapture

Eurasian lynx are individually identifiable by their unique coat markings, making them ideal candidates for capture–recapture (CMR) surveys. We evaluated the use of digital photography to estimate Eurasian lynx population abundance and density within the Bavarian Forest National Park. From November 2008 to January 2009 we placed 24 camera trap sites, each with two cameras facing each other on well–used walking tracks). The units were placed based on a systematic grid of 2.7 km. We captured five independent and three juvenile lynx and calculated abundance estimates using Program Mark. We also compared density estimates based on the MMDM method (Mean Maximum Distance Moved) from telemetry data (½MMDMGPS) and from camera trapping data (½MMDMCAM). We estimated that in an effectively sampled area of 664 km2 the Eurasian lynx density was 0.9 individuals/100 km2 with ½MMDMCAM. The Eurasian lynx density calculated with ½MMDMGPS was 0.4 individuals/100 km2 in an effectively sampled area of 1,381 km2. Our results suggest that long–term photographic CMR sampling on a large scale may be a useful tool to monitor population trends of Eurasian lynx in accordance with the Fauna–Flora–Habitat Directive of the European Union.

scholarly journals A spatially explicit approach for estimating space use and density of common genets

2014 ◽  
Vol 37 (1) ◽  
pp. 23-33
Author(s):  
P. Sarmento ◽  
◽  
J. Cruz ◽  
C. Eira ◽  
C. Fonseca ◽  
...  
Keyword(s):  
Spatial Model ◽  
Environmental Variables ◽  
Camera Trap ◽  
Grid Size ◽  
Future Research ◽  
Spatially Explicit ◽  
Density Estimates ◽  
Closed Population ◽  
Abundance Estimates ◽  
Capture Recapture

Many species that occur at low densities are not accurately estimated using capture–recapture methods as such techniques assume that populations are well–defined in space. To solve this bias, spatially explicit capture–recapture (SECR) models have recently been developed. These models incorporate movement and can identify areas where it is more likely for individuals to concentrate their activity. In this study, we used data from camera–trap surveys of common genets (Genetta genetta) in Serra da Malcata (Portugal), designed to compare abundance estimates produced by SECR models with traditional closed–capture models. Using the SECR models, we observed spatial heterogeneity in genet distribution and density estimates were approximately two times lower than those obtained from the closed population models. The non–spatial model estimates were constrained to sampling grid size and likely underestimated movements, thereby overestimating density. Future research should consider the incorporation of cost–weighed models that can include explicit hypothesis on how environmental variables influence the distance metric.

scholarly journals Integrating spatial capture-recapture models with variable individual identifiability

2020 ◽  
Author(s):  
Joel S. Ruprecht ◽  
Charlotte E. Eriksson ◽  
Tavis D. Forrester ◽  
Darren A. Clark ◽  
Michael J. Wisdom ◽  
...  
Keyword(s):  
Puma Concolor ◽  
Individual Recognition ◽  
Population Monitoring ◽  
Lynx Rufus ◽  
Individual Identification ◽  
Telemetry Data ◽  
Density Estimates ◽  
Gps Collars ◽  
Remote Cameras ◽  
Capture Recapture

AbstractMany applications in ecology depend on unbiased and precise estimates of animal population density. Spatial capture recapture models and their variants have become the preferred tool for estimating densities of carnivores. Within the spatial capture-recapture family are variants that require individual identification of all encounters (spatial capture-recapture), individual identification of a subset of a population (spatial mark-resight), or no individual identification (spatial count). In addition, these models can incorporate telemetry data (all models) and the marking process (spatial mark-resight). However, the consistency of results among methods and the relative precision of estimates in a real-world setting are unknown. Consequently, it is unclear how much and what type of data are needed to achieve satisfactory density estimates. We tested a suite of models to estimate population densities of black bears (Ursus americanus), bobcats (Lynx rufus), cougars (Puma concolor), and coyotes (Canis latrans). For each species we genotyped fecal DNA collected with detection dogs. A subset of individuals from each species were affixed with GPS collars bearing unique markings to be resighted by remote cameras set on a 1 km grid. We fit 10 models for each species ranging from those requiring no animals to be individually recognizable to others that necessitate full individual recognition. We then assessed the contribution of incorporating telemetry data to each model and the marking process to the mark-resight model. Finally, we developed an integrated hybrid model that combines camera, physical capture, genetic, and GPS data into a single hierarchical model. Importantly, we find that spatial count models that do not individually identify animals fail in all cases whether or not telemetry data are included. Results improved as models contained more information on individual identity. Models where a subset of individuals were identifiable yielded qualitatively similar results, but can produce quantitatively divergent estimates, suggesting that long-term population monitoring should use a consistent method across years. Incorporation of telemetry data and the marking process can produce more accurate and precise density estimates. Our results can be used to guide future study designs to efficiently estimate carnivore densities for better understanding of population dynamics, predator-prey relationships, and community assemblages.

scholarly journals Estimating the density of small population of leopard Panthera pardus using multi-session photographic□sampling data

2020 ◽  
Author(s):  
Mohammad S. Farhadinia ◽  
Pouyan Behnoud ◽  
Kaveh Hobeali ◽  
Seyed Jalal Mousavi ◽  
Fatemeh Hosseini-Zavarei ◽  
...  
Keyword(s):  
Population Density ◽  
Arid Regions ◽  
Animal Movement ◽  
Small Population ◽  
Conservation Priorities ◽  
Large Carnivores ◽  
Panthera Pardus ◽  
Demographic Stochasticity ◽  
Density Estimates ◽  
Capture Recapture

AbstractWest Asian drylands host a number of threatened large carnivores, including the leopard (Panthera pardus) which is limited to spatially scattered landscapes with generally low primary productivity. While conservation efforts have focused on these areas for several decades, reliable population density estimates are missing. Spatially-explicit capture-recapture (SECR) methodology, incorporating animal movement in density estimates, is widely used to monitor populations of large carnivores. We employed multi-session SECR modeling to estimate the density of a small population of leopard (Panthera pardus) in a mountainous stretch surrounded by deserts in central Iran. During 6724 camera trap nights, we detected eight and five independent leopards in 2012 and 2016 sessions, respectively. The top performing model demonstrated density estimates of 1.6 (95% CI = 0.9-2.9) and 1.0 (95% CI = 0.6-1.6) independent leopards/100 km2 in 2012 and 2016, respectively. Both sex and season had substantial effects on spatial scale (σ), with larger movements for males and during winter. Currently available estimates in arid regions represent some of the lowest densities across the leopard global range. These small populations are vulnerable to demographic stochasticity. Monitoring temporal changes in population density and composition can inform conservation priorities.

Population monitoring of a threatened gliding mammal in subtropical Australia

2016 ◽  
Vol 64 (6) ◽  
pp. 413 ◽  
Author(s):  
Ross L. Goldingay ◽  
Darren McHugh ◽  
Jonathan L. Parkyn
Keyword(s):  
Site Occupancy ◽  
Population Monitoring ◽  
Probability Of Detection ◽  
Imperfect Detection ◽  
North East ◽  
South Wales ◽  
Abundance Estimates ◽  
Petaurus Australis ◽  
Subtropical Australia

Population monitoring is fundamental to the conservation of threatened species. This study aimed to develop an effective approach for long-term monitoring of the yellow-bellied glider (Petaurus australis) in north-east New South Wales. We conducted repeat surveys to account for imperfect detection and used counts in abundance modelling to produce indices of abundance. We used simulations to explore refinements to our study design. Surveys over three consecutive years produced 195 detections with >95% of detections by call. The probability of detection varied across years and survey occasions, ranging from 0.22 to 0.71. Abundance estimates were remarkably constant across years, ranging from 2.3 ± 0.5 to 2.4 ± 0.6 individuals per site. Occupancy estimates were also constant across years (0.90–0.91). Simulations were run to investigate the influence of the number of surveys (2 or 3) and the number of survey sites (20, 40 or 50) on the probability of occupancy. The design that reduced bias and provided an adequate improvement to precision was that of three visits to 40 survey sites. This design should be adequate to detect a decline in population abundance. Further studies of this kind are needed to better understand the population dynamics of this species.

scholarly journals Density estimates and conservation of Leopardus pardalis southernmost population of the Atlantic Forest

2015 ◽  
Vol 105 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Carlos B. Kasper ◽  
Fábio D. Mazim ◽  
José B. G. Soares ◽  
Tadeu G. de Oliveira
Keyword(s):  
Camera Traps ◽  
Southern Brazil ◽  
Density Estimates ◽  
Leopardus Pardalis ◽  
Low Frequencies ◽  
Habitat Integrity ◽  
Capture Recapture ◽  
Green Corridor ◽  
Term Maintenance

ABSTRACT Using camera traps and capture/recapture analyses we recorded the presence and abundance of cat species at Turvo State Park, in southern Brazil. Ocelot [Leopardus pardalis (Linnaeus, 1758)] population density was estimated for two areas of the park, with differing management profiles. Density estimates varied from 0.14 to 0.26 indiv. km2. Another five cat species were recorded at very low frequencies, precluding more accurate analyses. We estimate 24 to 45 ocelots occur in the reserve, which is probably too small for long-term maintenance of the population, if isolated. However, if habitat integrity and connectivity between the Park and the Green Corridor of Misiones is maintained, an estimated ocelot population of 1,680 individuals should have long-term viability.

scholarly journals Monarch butterfly declines reported in Boyle et al. (2019) are biased by unexamined changes in museum collections over time

2019 ◽  
Author(s):  
Tyson Wepprich
Keyword(s):  
Species Interactions ◽  
Danaus Plexippus ◽  
Population Monitoring ◽  
Monarch Butterfly ◽  
Sampling Effort ◽  
World Population ◽  
Abundance Estimates ◽  
Collection Data ◽  
Over Time

AbstractMuseum records provide an underutilized source of information for documenting long-term changes in phenology, species interactions, and trait evolution. However, non-systematic collection data must be treated carefully if they are to approximate abundance, as trends may be confounded with spatial or temporal changes in sampling effort. Boyle et al. (2019b) argue that the relative abundance of Eastern North American Monarch butterflies (Danaus plexippus) has been in a long-term decline since the mid-20th century, following a similar decline in milkweed (Asclepias spp.) herbarium records. I demonstrate that this reported abundance trend is biased by the choice to standardize Monarch records as a proportion of all Lepidoptera collected. The sampling of Lepidoptera has changed systematically over time to favor moths, causing the apparent trend in Monarch records. With the data standardized more appropriately, I show that the trend in Monarch records shows no mid-century decline and increases over recent decades. As the trend in Monarch museum specimens contradicts the recent trend in Monarch abundance documented from systematic population monitoring, I argue that these records are unreliable for abundance estimates. The conclusion in Boyle et al. (2019b) that Monarch declines started in the mid-20th century is unwarranted both because the trend is biased by sampling changes in museum records and because the trend in Monarch records, when corrected, does not correspond with real-world population abundance.

scholarly journals Abundance and density estimates for common leopard Panthera pardus and clouded leopard Neofelis nebulosa in Manas National Park, Assam, India

Oryx ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 149-155 ◽  
Author(s):  
Jimmy Borah ◽  
Tridip Sharma ◽  
Dhritiman Das ◽  
Nilmani Rabha ◽  
Niraj Kakati ◽  
...  
Keyword(s):  
National Park ◽  
Camera Traps ◽  
Camera Trapping ◽  
Spatially Explicit ◽  
Panthera Pardus ◽  
Density Estimates ◽  
Clouded Leopard ◽  
Neofelis Nebulosa ◽  
Capture Recapture ◽  
The Common

AbstractEffective conservation of rare carnivores requires reliable estimates of population density for prioritizing investments and assessing the effectiveness of conservation interventions. We used camera traps and capture–recapture analysis to provide the first reliable abundance and density estimates for the common leopard Panthera pardus and clouded leopard Neofelis nebulosa in Manas National Park, India. In 57 days of camera trapping, with a total of 4,275 camera-trap days, we photo-captured 27 individually identified common leopards (11 males, 13 females and three unidentified), and 16 clouded leopards (four males, five females and seven unidentified). The abundance estimates using the Mh jackknife and Pledger model Mh were 47.0 and 35.6, respectively, for the common leopard, and 21.0 and 25.0, respectively, for the clouded leopard. Density estimates using maximum likelihood spatially-explicit capture–recapture were 3.4 ± SE 0.82 and 4.73 ± SE 1.43 per 100 km2 for the common and clouded leopards, respectively. Spatially-explicit capture–recapture provided more realistic density estimates compared with those obtained from conventional methods. Our data indicates that camera trapping using a capture–recapture framework is an effective tool for assessing population sizes of cryptic and elusive carnivores such as the common and clouded leopards. The study has established a baseline for the long-term monitoring programme for large carnivores in Manas National Park.

scholarly journals Estimating the density of a small population of leopards (Panthera pardus) in central Iran using multi-session photographic‐sampling data

2021 ◽  
Author(s):  
Mohammad S. Farhadinia ◽  
Pouyan Behnoud ◽  
Kaveh Hobeali ◽  
Seyed Jalal Mousavi ◽  
Fatemeh Hosseini-Zavarei ◽  
...  
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Animal Movement ◽  
Small Population ◽  
Central Iran ◽  
Large Carnivores ◽  
Panthera Pardus ◽  
Demographic Stochasticity ◽  
Density Estimates ◽  
Capture Recapture

AbstractWest Asian drylands host a number of threatened large carnivores, including the leopard (Panthera pardus) which is limited generally to areas with low primary productivity. While conservation efforts have focused on these areas for several decades, reliable population density estimates are missing for many of them. Spatially explicit capture–recapture (SECR) methodology is a widely accepted population density estimation tool to monitor populations of large carnivores and it incorporates animal movement in the statistical estimation process. We employed multi-session maximum-likelihood SECR modeling to estimate the density of a small population of leopard in a mountainous environment surrounded by deserts in central Iran. During 6724 camera trap nights, we detected 8 and 5 independent leopards in 2012 and 2016 sessions, respectively. The top-performing model produced density estimates of 1.6 (95% CI = 0.9–2.9) and 1.0 (95% CI = 0.6–1.6) independent leopards/100 km2 in 2012 and 2016, respectively. Both sex and season had substantial effects on spatial scale (σ), with larger movements recorded for males, and during winter. The estimates from our density estimation exercise represent some of the lowest densities across the leopard global range and strengthen the notion that arid habitats support low densities of the species. These small populations are vulnerable to demographic stochasticity, and monitoring temporal changes in their population density and composition is a critical tool in assisting conservation managers to better understand their population performance.

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