Linking monitoring and intervention for improved management of tigers in the Sundarbans of Bangladesh

Barlow, Adam; Ahmed, Md. Ishtiaq U.; Rahman, Md. Mizanur; Howlader, Alam; Smith, Alexander C.; Smith, James L.

doi:10.1016/j.biocon.2008.05.018

Cited by 22 publications

(28 citation statements)

References 28 publications

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“…Power is defined as 1-b, where b is the probability of Type II error (false negative). We selected 30% as an effect size that was probably large enough to be detectable with realistic sample sizes, but small enough to be reversible through management intervention (Barlow et al, 2008). We modelled the 50% decline largely to explore the trade off between effect size and sample size.…”

Section: Discussionmentioning

confidence: 99%

“…That being said, power increases with sample size. Other carnivore studies have used monitoring criteria of a = b = 0.2 (Barlow et al, 2008), which assumes equal economic, social, political and environmental costs of Type I and II errors (Mapstone, 1995). Using these criteria, annual effort of 12 replicates at each of a simple random sample of P65 sites would offer sufficient power to detect a 50% decline in brown hyaena occupancy in our study area over a 5 year period.…”

Section: Discussionmentioning

confidence: 99%

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Brown hyaenas on roads: Estimating carnivore occupancy and abundance using spatially auto-correlated sign survey replicates

Thorn

Green

Bateman

et al. 2011

Biological Conservation

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a b s t r a c tCarnivore survey protocols that properly address spatial sampling and detectability issues are seldom feasible at a landscape-scale. This limits knowledge of large-scale patterns in distribution, abundance and their underlying determinants, hindering conservation of globally threatened carnivore populations. Occupancy analysis of data from logistically efficient sign surveys along consecutive road segments (spatially auto-correlated replicates) offers a potential solution. We adapted and applied this newly-developed method over 62,979 km 2 of human-modified land in South Africa. Our aims were to (1) generate unbiased estimates of brown hyaena occupancy and abundance (2) investigate two suspected determinants of occupancy using a combination of biological and socio-economic sampling techniques, and (3) use simulations to evaluate the effort required for abundance and occupancy estimates with acceptable bias, precision and power. Brown hyaena occupancy was estimated at 0.748 (±SE 0.1), and estimated overall density in agricultural land (0.15/100 km 2 , ±SE 0.08) was an order of magnitude lower than in protected areas. Positive attitudes to carnivores and presence of wildlife farms exerted strong positive effects on occupancy, so changes in these factors may well exert monotonic impacts on local metapopulation status. Producing reliable occupancy and abundance estimates would require P6 replicates and P12 replicates per site respectively. Detecting 50% and 30% declines in brown hyaena occupancy with adequate power would require five annual surveys at P65 sites and P125 sites respectively. Our results suggest that protocols based on spatially auto-correlated sign survey replicates could be used to monitor carnivore populations at large, and possibly even country-wide spatial scales.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Brown hyaenas on roads: Estimating carnivore occupancy and abundance using spatially auto-correlated sign survey replicates

Thorn

Green

Bateman

et al. 2011

Biological Conservation

View full text Add to dashboard Cite

show abstract

“…For each of the eight SLR time steps we identified year 2000 land area that would fall below the rising elevation of the sea. To assess the potential range of tiger population for each time step, we combined three classes of relative tiger abundance (Barlow et al 2008) with two sets of three potential female tiger home range sizes, based on local telemetry of females (n = 2) and a literature review of home range sizes in other habitats. We derived two estimates of total breeding female population, which we merged with two estimates of male:female sex ratios to derive four estimates of total adult tiger populations at each SLR time step (see Supplementary Information for additional details on methods).…”

Section: Methodsmentioning

confidence: 99%

Sea level rise and tigers: predicted impacts to Bangladesh’s Sundarbans mangroves

et al. 2009

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The Sundarbans mangrove ecosystem, shared by India and Bangladesh, is recognized as a global priority for biodiversity conservation. Sea level rise, due to climate change, threatens the long term persistence of the Sundarbans forests and its biodiversity. Among the forests' biota is the only tiger (Panthera tigris) population in the world adapted for life in mangrove forests. Prior predictions on the impacts of sea level rise on the Sundarbans have been hampered by coarse elevation data in this low-lying region, where every centimeter counts. Using high resolution elevation data, we estimate that with a 28 cm rise above 2000 sea levels, remaining Electronic supplementary material The online version of this article (292 Climatic Change (2010) 98:291-298tiger habitat in Bangladesh's Sundarbans would decline by 96% and the number of breeding individuals would be reduced to less than 20. Assuming current sea level rise predictions and local conditions do not change, a 28 cm sea level rise is likely to occur in the next 50-90 years. If actions to both limit green house gas emissions and increase resilience of the Sundarbans are not initiated soon, the tigers of the Sundarbans may join the Arctic's polar bears (Ursus maritimus) as early victims of climate change-induced habitat loss.

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“…One independent research and awareness program supported by the US Fish and Wildlife Service (USFWS) has carried out population censuses of the Hoolock gibbon and created awareness among indigenous and local communities (Islam et al 2006;Muzaffar et al 2007). Recent studies have estimated the Bengal Tiger, Panthera tigris, population, using accepted scientific methods (Barlow et al 2008). Additionally, awareness about the tiger ecology, conservation and tiger-human conflicts has been increased.…”

Section: Forest Management and Threatened Speciesmentioning

confidence: 99%

The endangered forests of Bangladesh: why the process of implementation of the Convention on Biological Diversity is not working

et al. 2011

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Bangladesh has been a signatory to the Convention on Biological Diversity (CBD) although implementation of the convention has been poor. We independently assessed the extent to which the program of work (POW) of the CBD has been implemented in Bangladesh by carrying out workshops involving local communities, conservation organizations, universities, and government departments involved in forest conservation. Our analyses indicate that there is little or no understanding of the

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Linking monitoring and intervention for improved management of tigers in the Sundarbans of Bangladesh

Cited by 22 publications

References 28 publications

Brown hyaenas on roads: Estimating carnivore occupancy and abundance using spatially auto-correlated sign survey replicates

Brown hyaenas on roads: Estimating carnivore occupancy and abundance using spatially auto-correlated sign survey replicates

Sea level rise and tigers: predicted impacts to Bangladesh’s Sundarbans mangroves

The endangered forests of Bangladesh: why the process of implementation of the Convention on Biological Diversity is not working

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