Provide an instance where the population size of species can be estimated indirectly without actually in natural parks is based on pugmarks.

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for an instance where the population size of a species can be estimated indirectly using pugmarks, without conducting direct counts in natural parks.

2. **Identifying the Species**: A suitable species for this example is the tiger, which is often found in national parks and reserves.

3. **Indirect Estimation Method**: Instead of directly counting the number of tigers, researchers can estimate the population size by analyzing pugmarks (footprints) and fecal pellets (scat) left by the tigers in their habitat.

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