There are several journals and publications that provide topic-wise case studies and examples for the Zoology optional subject. These resources can greatly assist UPSC aspirants in preparing for the examination. Here are some highly recommended journals and publications:

1. Journal of Zoology:
- This journal covers a wide range of topics in zoology, including animal behavior, ecology, evolution, and conservation.
- It publishes original research articles, review papers, and case studies that provide valuable insights into various aspects of zoology.
- The journal also includes examples of field studies and experiments conducted by zoologists worldwide.

2. The Journal of Experimental Zoology:
- This publication focuses on experimental research in zoology and provides a platform for the presentation of innovative studies and findings.
- It covers topics such as animal physiology, development, genetics, and morphology.
- The journal often includes case studies that illustrate the application of experimental techniques and methodologies in zoology.

3. Animal Behaviour:
- This journal primarily focuses on the study of animal behavior, including social behavior, communication, and cognition.
- It publishes original research articles, reviews, and case studies that provide insights into the behavior of different animal species.
- The journal often includes examples of observational studies and experiments that shed light on various behavioral phenomena.

4. Journal of Animal Ecology:
- This publication focuses on the ecological aspects of animal life, including population dynamics, community interactions, and habitat preferences.
- It publishes research articles, reviews, and case studies that provide a comprehensive understanding of animal ecology.
- The journal often includes examples of long-term ecological studies and experiments conducted in diverse ecosystems.

5. Conservation Biology:
- This journal primarily focuses on the conservation of biodiversity, including the study of threatened and endangered species, habitat conservation, and conservation policy.
- It publishes research articles, case studies, and reviews that highlight the challenges and solutions in conservation biology.
- The journal often includes examples of successful conservation initiatives and the application of conservation principles in real-world scenarios.

These journals and publications provide a wealth of information and case studies that are relevant to the Zoology optional subject. Aspiring UPSC candidates can refer to these sources to gain a deeper understanding of various topics in zoology and to develop a well-rounded preparation strategy.