Population of California Candor is declining due to

Options

A. Increasing pollution
B. Increasing cleanlines
C. Increasing pesticide concentration
D. Change in surroundings.

Answer

**Step-by-Step Solution:**

1. **Identify the Species**: The question refers to the California Condor, which is the largest North American land bird.

2. **Understand the Context**: The California Condor population has been declining, and it became extinct in the wild in 1987. However, efforts have been made to reintroduce the species into the wild.

3. **Reintroduction Efforts**: The California Condor has been reintroduced to various regions, including Northern Arizona, Southern Utah, and the coastal mountains of Central and Southern California.

4. **Analyze the Options**: The options given for the cause of the population decline are:
- Increasing population
- Increasing cleanliness
- Increasing pesticide concentration
- Change in surroundings

5. **Evaluate the Causes**:
- Increasing population does not directly cause a decline in the condor population.
- Increasing cleanliness is unlikely to be a factor affecting the condors negatively.
- Increasing pesticide concentration could potentially harm wildlife, but it is not the primary cause of decline for California Condors.
- Change in surroundings could affect their habitat, but the most significant factor is related to their feeding habits.

6. **Identify the Main Cause**: The primary reason for the decline in the California Condor population is lead poisoning from ingesting spent ammunition found in carcasses, as they forage exclusively on dead animals.

7. **Conclusion**: Therefore, the correct answer to the question regarding the decline of the California Condor population is due to increasing pesticide concentration, specifically the lead exposure from spent ammunition.

**Final Answer**: The population of California Condor is declining due to increasing pesticide concentration, specifically lead poisoning from spent ammunition.

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