In this situation, it's helpful to remember a few things:
- Peer review is often an iterative process. You submit a manuscript, reviewers make suggestions, you improve the paper based on their suggestions, they may have additional suggestions after seeing the revised version, and so forth.
Knowing this, your goal is not to make sure that you can provide a final, unchanging response to each question or request from the reviewers. Your goal is to identify what changes will actually improve the manuscript and to make those changes, and then respectfully address the other comments. And if a reviewer's request is unclear, it's fine to state that and ask for clarification.
The reviewer has asked for data on average rates over time. In context, we are unsure whether they are interested in average hatching rates or average daily velocity. If the reviewer can clarify what rates they are interested in, we are happy to provide the requested data.
- Editors are often scientists as well, and they have discretion to decide whether you have adequately addressed the reviewers' concerns. They are also (generally) capable of judging whether a question is confusing or off topic.
I've had many times when a reviewer's question either didn't make any sense in context, or where the meaning and the requested change was ambiguous. In those cases, I've tried to make clear what about the question was confusing and to express a willingness to further edit the manuscript if the question can be clarified. In nearly every case, the editor has accepted the manuscript without going back to the reviewer for another round of comments.
This question concerns the migratory habits of starlings, while our focuses on the feeding habits of seagulls. We are unsure how the reviewer's proposed modifications fit with the aims of the manuscript. If the reviewer can clarify the changes they would like to see, we would be happy to update the manuscript accordingly.