On feeding on which type of food ,the accumulation of DDT is maximum in birds ?

Options

A. Fishes
B. leaves
C. Insects
D. Seeds

Answer

**Step-by-Step Text Solution:**

1. **Understanding Bio-magnification**: The question revolves around the concept of bio-magnification, which is the process where certain non-degradable pollutants, such as DDT (Dichloro-Diphenyl-Trichloroethane), accumulate in organisms at higher trophic levels in a food chain.

2. **Identifying Trophic Levels**: In a typical aquatic food chain, we can identify several trophic levels:
- **Producers**: Phytoplankton (which absorb DDT from the water).
- **Primary Consumers**: Zooplankton (which feed on phytoplankton).
- **Secondary Consumers**: Small fishes (which feed on zooplankton).
- **Tertiary Consumers**: Birds (which feed on small fishes).

3. **Accumulation of DDT**: As we move up the trophic levels from phytoplankton to birds, the concentration of DDT increases. This is because each level consumes the organisms from the previous level, leading to higher concentrations of DDT in the bodies of the organisms at the top of the food chain.

4. **Impact on Birds**: When birds, as top carnivores, feed on small fishes, they ingest the highest concentration of DDT. This accumulation can disrupt their calcium metabolism, leading to issues such as thinning of eggshells and increased rates of premature egg breakage, ultimately affecting bird populations.

5. **Conclusion**: Therefore, the maximum accumulation of DDT in birds occurs when they feed on small fishes, as this places them at the highest trophic level in the food chain where DDT concentration is the highest.

**Final Answer**: Birds accumulate maximum DDT when feeding on small fishes.

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