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Featured researches published by Rajan Amin.


Conservation Biology | 2009

Monitoring change in vertebrate abundance: the living planet index.

Ben Collen; Jonathan Loh; Sarah Whitmee; Louise McRae; Rajan Amin; Jonathan E. M. Baillie

The task of measuring the decline of global biodiversity and instituting changes to halt and reverse this downturn has been taken up in response to the Convention on Biological Diversitys 2010 target. It is an undertaking made more difficult by the complex nature of biodiversity and the consequent difficulty in accurately gauging its depletion. In the Living Planet Index, aggregated population trends among vertebrate species indicate the rate of change in the status of biodiversity, and this index can be used to address the question of whether or not the 2010 target has been achieved. We investigated the use of generalized additive models in aggregating large quantities of population trend data, evaluated potential bias that results from collation of existing trends, and explored the feasibility of disaggregating the data (e.g., geographically, taxonomically, regionally, and by thematic area). Our results show strengths in length and completeness of data, little evidence of bias toward threatened species, and the possibility of disaggregation into meaningful subsets. Limitations of the data set are still apparent, in particular the dominance of bird data and gaps in tropical-species population coverage. Population-trend data complement the longer-term, but more coarse-grained, perspectives gained by evaluating species-level extinction rates. To measure progress toward the 2010 target, indicators must be adapted and strategically supplemented with existing data to generate meaningful indicators in time. Beyond 2010, it is critical a strategy be set out for the future development of indicators that will deal with existing data gaps and that is intricately tied to the goals of future biodiversity targets.


PLOS ONE | 2007

Improvements to the Red List Index.

Stuart H. M. Butchart; H. Resit Akçakaya; Janice Chanson; Jonathan E. M. Baillie; Ben Collen; Suhel Quader; Will R. Turner; Rajan Amin; Simon N. Stuart; Craig Hilton-Taylor

The Red List Index uses information from the IUCN Red List to track trends in the projected overall extinction risk of sets of species. It has been widely recognised as an important component of the suite of indicators needed to measure progress towards the international target of significantly reducing the rate of biodiversity loss by 2010. However, further application of the RLI (to non-avian taxa in particular) has revealed some shortcomings in the original formula and approach: It performs inappropriately when a value of zero is reached; RLI values are affected by the frequency of assessments; and newly evaluated species may introduce bias. Here we propose a revision to the formula, and recommend how it should be applied in order to overcome these shortcomings. Two additional advantages of the revisions are that assessment errors are not propagated through time, and the overall level extinction risk can be determined as well as trends in this over time.


Environmental Management | 2010

Remotely-Sensed Active Fire Data for Protected Area Management: Eight-Year Patterns in the Manas National Park, India

Chihiro Takahata; Rajan Amin; Pranjit Kumar Sarma; Gitanjali Banerjee; William Oliver; John E. Fa

The Terai-Duar savanna and grasslands, which once extended along most of the Himalayan foothills, now only remain in a number of protected areas. Within these localities, grassland burning is a major issue, but data on frequency and distribution of fires are limited. Here, we analysed the incidence of active fires, which only occur during the dry season (Nov.–Mar.), within a significant area of Terai grasslands: the Manas National Park (MNP), India. We obtained locations of 781 fires during the 2000–2008 dry seasons, from the Fire Information for Resource Management System (FIRMS) that delivers global MODIS hotspot/fire locations using remote sensing and GIS technologies. Annual number of fires rose significantly from around 20 at the start of the study period to over 90 after 2002, with most (85%) detected between December and January. Over half of the fires occurred in tall grasslands, but fire density was highest in wetland and riverine vegetation, dry at the time. Most burning took place near rivers, roads and the park boundary, suggesting anthropogenic origins. A kernel density map of all recorded fires indicated three heavily burnt areas in the MNP, all within the tall grasslands. Our study demonstrates, despite some technical caveats linked to fire detection technology, which is improving, that remote fire data can be a practical tool in understanding fire concentration and burning temporal patterns in highly vulnerable habitats, useful in guiding management.


Oryx | 2013

Population status, structure and distribution of the greater one-horned rhinoceros Rhinoceros unicornis in Nepal

Naresh Subedi; Shant Raj Jnawali; Maheshwar Dhakal; Narendra Man Babu Pradhan; Babu Ram Lamichhane; Sabita Malla; Rajan Amin; Yadvendradev V. Jhala

We assessed the abundance and distribution of the greater one-horned or Indian rhinoceros Rhinoceros unicornis in all its potential habitats in Nepal, using block counts. In April 2011 5,497 km were searched in 3,548 elephant-hours over 23 days. The validity of the block count was assessed by comparing it with counts obtained from long-term monitoring using photographic identification of individual rhinoceroses (ID-based), and estimates obtained by closed population sighting–mark–resighting in the 214 km 2 of Chitwan National Park. A total of 534 rhinoceroses were found during the census, with 503 in Chitwan National Park (density 1 km −2 ), 24 in Bardia National Park (0.28 km −2 ) and seven in Suklaphanta Wildlife Reserve (0.1 km −2 ). In Chitwan 66% were adults, 12% subadults and 22% calves, with a female : male ratio of 1.24. The population estimate from sighting–mark–resighting was 72 (95% CI 71–78). The model with different detection probabilities for males and females had better support than the null model. In the Sauraha area of Chitwan estimates of the population obtained by block count (77) and ID-based monitoring (72) were within the 95% confidence interval of the estimate from sighting–mark–resighting. We recommend a country-wide block count for rhinoceroses every 3 years and annual ID-based monitoring in a sighting–mark–resighting framework within selected subpopulations. The sighting–mark–resighting technique provides the statistical rigour required for population estimates of the rhinoceros in Nepal and elsewhere.


Oryx | 2013

Invasive mikania in Chitwan National Park, Nepal: the threat to the greater one-horned rhinoceros Rhinoceros unicornis and factors driving the invasion

Sean T. Murphy; Naresh Subedi; Shant Raj Jnawali; Babu Ram Lamichhane; Gopal Prasad Upadhyay; Richard Kock; Rajan Amin

As part of a census of the Indian rhinoceros Rhinoceros unicornis a survey was conducted to measure the extent of invasion by the neotropical plant mikania Mikania micrantha across major habitats of Chitwan National Park important for the conservation of the rhinoceros. Previous work has demonstrated that this fire-adapted plant can smother and kill native flora such as grasses and sapling trees, several of which are important fodder plants of the rhinoceros. Here, additional studies were conducted on the risks of anthropogenic factors (natural resource collection and grassland burning) contributing to the spread and growth of the plant. Mikania is currently found across 44% of habitats sampled and almost 15% of these have a high infestation (> 50% coverage). Highest densities were recorded from riverine forest, tall grass and wetland habitats and this is where the highest numbers of rhinoceroses were recorded in the habitats surveyed during the census. Local community dependence on natural resources in the core area of the Park is high. The range and volume of resources (e.g. fodder) collected and the distances travelled all pose a high risk of the spread of mikania. Of greater significance is the annual burning of the grasslands in the Park by local communities, estimated at 25–50% of the total area. It is imperative, therefore, that core elements of a management plan for mikania incorporate actions to control burning, reduce spread and raise awareness about best practice for local resource management by local communities.


Journal of East African Natural History | 2010

Sengi (Elephant-Shrew) Observations from Northern Coastal Kenya

Samuel Andanje; Bernard Agwanda; Grace W. Ngaruiya; Rajan Amin; Galen B. Rathbun

ABSTRACT The biodiversity of northern coastal Kenya is poorly understood because security problems and poor infrastructure have discouraged access to the area. However, the wooded areas in the region have great potential for harbouring unique and rare species, including sengis or elephant-shrews (Macroscelidea). Based on recent surveys of the Boni and Dodori National Reserves, which are between the Tana River and the Somali border, the ranges of the rufous sengi (Elephantulus rufescens) and four-toed sengi (Petrodromus tetradactylus) have been extended. Although the golden-ramped sengi (Rhynchocyon chrysopygus) of coastal Kenya south of the lower Tana River was assumed to occur in the Boni forest region, this now appears to be incorrect. The Rhynchocyon east of the lower Tana River is definitely not R. chrysopygus, but rather resembles taxa found hundreds of kilometres to the south. Determining the taxonomic status of what may be a new form of Rhynchocyon will require the collection of voucher specimens and DNA tissues for detailed analyses.


Knowledge Based Systems | 2003

Intelligent data analysis for conservation: experiments with rhino horn fingerprint identification

Rajan Amin; Max Bramer; Richard H. Emslie

Conservation is an area in which a great deal of data has been collected over many years. Intelligent Data Analysis offers the possibility of analysing this data in an automatic fashion to map characteristics, identify trends and offer guidance for conservation action. This paper is concerned with the use of techniques of Intelligent Data Analysis for an important task in animal conservation: the identification of the species and origin of illegally traded or confiscated African rhino horn. It builds on an earlier analysis by the African Rhino Specialist Group. It is demonstrated that it is possible to distinguish between both species and country of origin with a high degree of accuracy and that the results are also likely to be suitable for use in court.


Oryx | 2015

Population and habitat assessment of the Critically Endangered hirola Beatragus hunteri in Tsavo East National Park, Kenya

James Probert; Ben Evans; Sam Andanje; Richard Kock; Rajan Amin

The Critically Endangered hirola Beatragus hunteri exists in two populations, a natural population on the Kenyan–Somali border and a translocated population in Tsavo East National Park, Kenya. The Tsavo population is becoming increasingly important for the survival of the hirola yet its status is unknown and little is understood about the factors that limit its growth. Here we report the size, distribution and demographic parameters of the Tsavo population of hirola and consider whether insufficient suitable habitat could be limiting its growth. The Tsavo population has not increased since 2000, when the last census was carried out, but neither has it significantly decreased. The importance of habitat as a limiting factor is dependent on the hirolas ability to utilize marginal habitat.


Oryx | 2011

A new population of the Critically Endangered Aders’ duiker Cephalophus adersi confirmed from northern coastal Kenya

Samuel A. Andanje; Andrew E. Bowkett; Bernard Agwanda; Grace W. Ngaruiya; Amy B. Plowman; Tim Wacher; Rajan Amin

Aders’ duiker Cephalophus adersi is a small antelope endemic to the coastal forests of east Africa. Threatened by habitat loss and hunting, the species is categorized as Critically Endangered on the IUCN Red List. Until recently Aders’ duiker was known to persist only on Zanzibar, Tanzania, and in the Arabuko-Sokoke Forest National Reserve, Kenya. However, in 2004 a sighting of a single individual was reported from the Dodori forest in northern coastal Kenya, raising the possibility that the species survives elsewhere. Subsequently, an opportunistic camera-trap survey was conducted in September and October 2008 to establish the occurrence of Aders’ duiker in Kenyan coastal forests north of the Tana River. One hundred and fifty six images of Aders’ duikers were obtained from 12 of 28 camera-trap sites (46 of 358 camera-trap days), confirming the existence of a population of Aders’ duiker in the Boni–Dodori forest both inside and outside the National Reserves. In addition, we sighted individuals of the species on three occasions. The relatively high encounter rates per unit effort compared to similar data from Arabuko-Sokoke forest suggest the Boni–Dodori population is significant. Initial surveys of the local Awer community revealed that Aders’ duiker is well known by the name guno . These findings significantly improve the conservation prospects for Aders’ duiker and highlight the need for greater research and management efforts in the poorly known Boni–Dodori forest.


Oryx | 2017

Rapid recovery of tigers Panthera tigris in Parsa Wildlife Reserve, Nepal

Babu Ram Lamichhane; Chiranjibi Prasad Pokheral; Shashank Poudel; Dipendra Adhikari; Sailendra Raj Giri; Santosh Bhattarai; Tek Raj Bhatta; Rob Pickles; Rajan Amin; Krishna Prasad Acharya; Maheshwar Dhakal; Uba Raj Regmi; Ashok Kumar Ram; Naresh Subedi

Information on density and abundance of globally threatened species such as tigers Panthera tigris is essential for effective conservation as well as to evaluate the success of conservation programmes. We monitored tigers in Parsa Widlife Reserve, Nepal, using camera traps, in 2013, 2014 and 2016. Once believed to be a sink for tigers from adjacent Chitwan National Park, Parsa now provides a new hope for tigers. Spatially explicit capture–recapture analysis over 3 survey years revealed an increase in tiger density from 0.78 to 1.38 individuals per 100 km2 from 2013 to 2016. The tiger abundance was estimated to be seven (6–13), 11 (10–16) and 17 (17–20) in 2013, 2014 and 2016, respectively. Resettlement of communities from the core area, reduced anthropogenic pressure, and improved security have made Parsa Wildlife Reserve a suitable habitat for tigers. Tiger abundance increased considerably within a 5 km radius of the evacuated village sites, from two in 2013 to eight in 2014 and 10 in 2016. Population turnover has remained moderate (

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Richard Kock

Royal Veterinary College

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Ben Collen

University College London

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Tim Wacher

Zoological Society of London

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Andrew E. Bowkett

Whitley Wildlife Conservation Trust

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Louise McRae

Zoological Society of London

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