Read the following statements.

A. Tiger census in our national parks is often based on pug marks and fecal pellets.

B. Size of population for any species is not a static parameter.

C. Percent cover or biomass cannot be a meaningful measure to know population density.

D. Population density is always measured in numbers.

How many of the given statements are true?

The tiger census in our national parks and tiger reserves is often based on pug marks and fecal pellets. The size of a population of any species is not a static parameter. It keeps changing in time, depending on various factors including food availability, predation pressures, and weather. The per cent cover or biomass is a meaningful measure of the population size. Example; In an area, if there are 200 carrot grass (Parthenium hysterophorus) plants but only a single huge banyan tree with a large canopy, stating that the population density of banyan is low relative to that of carrot grass amounts to underestimating the enormous role of the Banyan in that community. Population size, technically called population density, need not necessarily be measured in numbers only.