Explain how habitat fragmentation can reduce genetic diversity in the population of the Indian hornbill (Buceros rhinoceros) with a brief example. Mention at least three mechanisms involved.

Step-by-step solution

1. Step 1: Define habitat fragmentation – the breaking up of a large, continuous habitat into smaller, isolated patches.
2. Step 2: Explain that Indian hornbills are large, territorial birds that travel long distances to find food and mates. Fragmented forests limit their movement between patches.
3. Step 3: Reduced gene flow – with fewer movements, individuals from different patches breed less, leading to subpopulations that are more genetically distinct.
4. Step 4: Genetic drift – in small, isolated subpopulations, random changes in allele frequencies can cause loss of rare alleles over time.
5. Step 5: Inbreeding – limited mate options increase the likelihood of mating between related individuals, which can lead to homozygosity of deleterious alleles and reduced heterozygosity.
6. Step 6: Bottleneck effect – if a patch loses many individuals (e.g., due to hunting), the remaining few may not represent the full genetic diversity of the original population.
7. Step 7: Summarize that these mechanisms collectively reduce the overall genetic diversity of the hornbill species across its range.

Concept tested: Impact of fragmentation on genetic diversity

Published 28 September 2026 · How this solution was prepared and checked