Statistical Inference from Capture Data on Closed Animal Populations

https://onlinelibrary.wiley.com/doi/epdf/10.1111/ddi.12967

Multi‐scale habitat modelling identifies spatial conservation priorities for mainland clouded leopards (Neofelis nebulosa)

Camera trapping studies have become increasingly popular to produce population estimates of individually recognisable mammals. Yet, monitoring techniques for rare species which occur at extremely low densities are lacking. Additionally, species which have unpredictable movements may make obtaining reliable population estimates challenging due to low detectability. Our study explores the effectiveness of intensive camera trapping for estimating cheetah (Acinonyx jubatus) numbers. Using both a more traditional, systematic grid approach and pre-determined, targeted sites for camera placement, the cheetah population of the Northern Tuli Game Reserve, Botswana was sampled between December 2012 and October 2013. Placement of cameras in a regular grid pattern yielded very few (n = 9) cheetah images and these were insufficient to estimate cheetah density. However, pre-selected cheetah scent-marking posts provided 53 images of seven adult cheetahs (0.61 ± 0.18 cheetahs/100km²). While increasing the length of the camera trapping survey from 90 to 130 days increased the total number of cheetah images obtained (from 53 to 200), no new individuals were recorded and the estimated population density remained stable. Thus, our study demonstrates that targeted camera placement (irrespective of survey duration) is necessary for reliably assessing cheetah densities where populations are naturally very low or dominated by transient individuals. Significantly our approach can easily be applied to other rare predator species.

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Trapping Elusive Cats: Using Intensive Camera Trapping to Estimate the Density of a Rare African Felid

Effects of temporary closure of a national park on leopard movement and behaviour in tropical Asia

Habitat use and predicted range for the mainland clouded leopard Neofelis nebulosa in Peninsular Malaysia

Effective 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 M h jackknife and Pledger model M h 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.

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

Effective 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 km 2 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.

Abundance and density estimates for common leopard Panthera pardus and clouded leopard Neofelis nebulosa in Manas National Park, Assam, India J IMMY B ORAH ,T RIDIP S HARMA ,D HRITIMAN D AS ,N ILMANI R ABHA ,N IRAJ K AKATI A JIT B ASUMATARY ,M. F IROZ A HMED and J OSEPH V ATTAKAVEN

Manas National Park in Assam, India, is a UNESCO World Heritage Site, and part of an Indian Tiger Reserve, Elephant Reserve and Biosphere Reserve. During late 1980's & 1990's it faced tremendous anthropogenic pressure due to ethnic agitation in the area resulting in large scale destruction of the forest and its wildlife. However, after the resolution of this agitation, Manas is on its way back to normalcy. Camera trapping surveys that were conducted to determine tiger and prey status also helped in obtaining the first detailed baseline data of carnivores in the park in the post- conflict period. Here we present information obtained on major carnivore's presence in Manas. We recommend more research based studies to understand the existing carnivore diversity and to understand whether any management interventions aimed

Diversity of carnivores in Ma- nas National Park - a World Heritage Site, Assam, India

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Grassland-Woodland Transitions Over Decadal Timescales in the Terai-Duar Savanna and Grasslands of the Indian Subcontinent

Summary One of the multiple threats to protected areas worldwide, invasive plant species have the potential to decrease biodiversity and ecosystem function. We studied changes in infestation by two widespread invasive plant species – Chromolaena odorata and Mikania micrantha – in India’s Manas National Park, a critical conservation site for threatened flora and fauna. Based on field surveys in 2011 and 2019, we found that C. odorata and M. micrantha were present in most of the sampled plots and had newly invaded over 20% of the plots. However, the abundance of M. micrantha decreased in 45% of the plots while C. odorata increased in >50% of the plots. We used a decision tree-based regression with environmental variables as predictors to generate the distribution, abundance and invasion risk maps of the two species. Among environmental variables, road proximity and fire frequency had the strongest influences, respectively, on C. odorata and M. micrantha. Invaded quadrats exhibited lower native-plant diversity than non-invaded quadrats, and C. odorata specifically had a strong negative association with native-plant community structure. These invasive species have increased their range and abundance, and our predicted invasion risk maps indicate the areas where management intervention is urgently needed.

Dhritiman Das

Papers

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

Abundance and density estimates for common leopard Panthera pardus and clouded leopard Neofelis nebulosa in Manas National Park, Assam, India J IMMY B ORAH ,T RIDIP S HARMA ,D HRITIMAN D AS ,N ILMANI R ABHA ,N IRAJ K AKATI A JIT B ASUMATARY ,M. F IROZ A HMED and J OSEPH V ATTAKAVEN

Diversity of carnivores in Ma- nas National Park - a World Heritage Site, Assam, India

Grassland-Woodland Transitions Over Decadal Timescales in the Terai-Duar Savanna and Grasslands of the Indian Subcontinent

Grass fires and road structure influence plant invasions in a critical wildlife habitat in north-eastern India