Research Article: Gopalaswamy M. A., Karanth K. U., Delampady M., Stenseth C. N. (2019). How sampling‐based overdispersion reveals India’s tiger monitoring orthodoxy. Published in Conservation Science and Practice.

Blog Author: Aishwarya Anilkumar

Highlights:

  • Without sufficient scientific support, organisations in charge of the recovery of endangered species can overestimate population trends. This is referred to in conservation literature as the “political population.”
  • A group of scientists investigates cases of political populations in India’s tiger number.
  • This study looks at the reports of  National Tiger Estimation as part of India’s official tiger monitoring program and statically introspects their reports on tiger population size over a 12-year period.
  • Scientists in this study argue how India’s claims of a doubling of tiger population size are not backed by reliable scientific evidence.

 

Animal monitoring programs assist in estimating population dynamics such as abundance and trends. These further aid us in answering clearly defined scientific and management questions. A monitoring program should address two key sources of uncertainty, improper sampling, and imperfect detection, in order to produce robust conclusions regarding the dynamics of animal populations. Monitoring programs for one of the world’s most iconic mammals appear to routinely ignore these uncertainties which could lead to exaggerated claims about their population dynamics.

Have you heard of the term ‘political populations’? Conservation and protection of large carnivores are particularly prone to political influence. It has an effect on how their demographic data (abundance and trend) and related policies are reported. Without sufficient scientific support, organisations in charge of the protection and recovery of iconic mammal species may overestimate population trends. Such populations are referred to as ‘political populations’ in conservation literature.

Inquisitive scientists from the Indian Statistical Institute, Wildlife Conservation Society, National Centre for Biological Sciences, and Centre for Ecological and Evolutionary Synthesis investigated cases of political populations in India’s tiger number. The paper discusses four official surveys of 2006, 2010, 2014, and 2018 conducted during the National Tiger Estimation (NTE). This interesting study statistically introspects and criticizes the sampling methodology used in India’s official tiger monitoring program. They discuss how the estimation of abundance at large spatial scales is often impractical due to ecological, environmental, and logistical constraints.

Scientists discuss how double-sampling strategy, a technique used in large-scale spatial investigations, must be followed in order to arrive at a trustworthy abundance estimation. To put it simply, this entails doing rigorous, intensive surveys in a selection of sampled sites, then conducting less thoroughintensive but feasible surveys in a larger area and developing an index calibrating model to get to abundance. The study therefore comes to the conclusion that the survey done by NTE includes methodological ambiguities and that the tiger population size and occupancy reported from Indian tiger surveys are the outcomes of an unreliable monitoring program. The paper then explores how these findings do not enhance or add to our present understanding of the dynamics of wild animal populations in ecology. Thus, the experts contend that there is insufficient data to support India’s claims that the size of the tiger population doubled over a 12-year period (from 2006 to 2018).

The researchers hypothesise that these situations arise when organisations are under pressure to estimate population metrics for elusive species at broad spatial scales. The paper argues that monitoring systems should be created to address specific scientific or management concerns rather than attempting to satisfy arbitrary social or funding-related expectations.

 

Keywords: Political Population, Tigers, Panthera tigris, tiger population, monitoring programs, National Tiger Estimation, Tiger Census, Tiger Survey, Large Carnivores, Conservation.

You can access the original article here.