Urbanization Influences on the Song Diversity of the Eurasian Nuthatch (Sitta europaea) in Northeast China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article analyzes the effect of urbanization on different components of the vocalizations of the Eurasian Nuthatch (Sitta europaea) in a region of northeastern China. The choice of this species is particularly interesting since very few studies have focused on changes in its song within urban environments. However, the manuscript has significant issues, not necessarily due to its design but primarily because of the way it is presented and written.

The writing problems severely hinder the assessment of the manuscript's importance and its scientific soundness for the research community. For instance, it is unclear how many individuals were recorded in each area and the total number of recordings, both overall and per study site. This lack of information makes it difficult to draw conclusions from the results presented. Additionally, the text requires substantial editing regarding language, punctuation, referential integrity, capitalization, and professional English review.

Almost all sections of the manuscript would benefit from significant improvement and clarification of the methods, both in the fieldwork and the statistical analyses.

The introduction is overly vague. There are two paragraphs broadly discussing urbanization, with one specifically addressing homogenization, but they are only loosely connected to the article's focus. The introduction would be more appropriate if the authors first provided a general overview, followed by a deeper focus on the impact of urbanization on bird vocalizations, supported by a comprehensive review of the literature (there are numerous studies and reviews on this topic). This would better justify the choice of the study species and clarify whether it has been the subject of similar research before.

For readers unfamiliar with this region of China, the description of the study sites is insufficient to understand the potential changes in urbanization levels, noise, or human presence that might explain differences in the nuthatch's song. This lack of detail makes interpreting the results nearly impossible.

The description of the statistical analysis is very vague. Was the Mann-Whitney U test applied to all possible site combinations? Why was only this test used to compare two independent samples? Why not compare all sites simultaneously using a simple non-parametric test like Kruskal-Wallis? Was any post-hoc correction applied? Why are error bars missing from the graphs? How different are the songs within each study site?

Although the results might be interesting, they are significantly limited by their poor presentation. For example, why were only two of the six study sites selected for the homogenization analysis during the breeding season? Would the results change if all six sites were analyzed? Were only those two sites visited?

The figures also require substantial improvement. While Figure 1 helps locate the study sites, it could provide more explanatory details about the characteristics of the six study areas. Depending on the scale, adding a base orthophoto image could help readers unfamiliar with the region infer the urbanization levels of each site. Figures 2, 3, and 4 could potentially be merged into a single figure to enhance clarity and conciseness.

Comments on the Quality of English Language

A professional review of the English language is necessary

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Research on the impacts of urbanization on wildlife is critically important, and there is certainly a large volume of research on the impacts of noise on wildlife, including on bird song. Therefore, your work has the potential to be an important contribution to the literature on urban ecology. Unfortunately, your manuscript has some significant flaws which need to be addressed. The main problem is in your methods, which, in turn, leads to issues with your results and discussion. Your objective is not clearly stated, but is presumably comparing nuthatch vocalization in areas of different levels of urbanization. Your methods lack any description of the study site characteristics, which is crucial for interpreting your results. You also do not state what time(s) of year vocalizations were recorded, what year(s) data were collected, or what your sample sizes are. All of this hinders what you can conclude. In your results and discussion, you found a few differences between sites, but don't discuss the significance of those findings, and that is largely because you don't detail the differences between the sites in your methods. Without that information, you really cannot say anything about the impact of urbanization on nuthatch vocalizations and what it means for them and other bird species. I have made more detailed comments and corrections on the manuscript, which I have attached to my review. I wish you well in your efforts to publish your work.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This is a novel approach to study the effect of urbanization on birds, what make the study especially valued. Goals and methods are well-planned and results clearly presented. I have, however, few suggestions to improve/clarify in the 'Introduction' and 'Methods' section. Both the species investigated and the object of investigation (nuthatch's vocalization) are poorlely presented. In China, The Eurasian Nuthatch is one of 11 species of the genus Sitta. In the study areas, probaly only one species occurs. Sitta villosa may be sympatric with S. europaea in this region. All other species occur in the southern tropical part of China. Most readers will not know this, so authors must make it clear, that only one Sitta species occurs in the extreme north of China. This is important to say, as for example in USA, few Sitta species are sympatric. Sympatry or allopparty may influence species vocalization. The European Nuthatch is a vocal species, so the issue of its diverse vocalization should be presented in 'Introduction'. It should be mentioned that it is vocal throughout the year, with an activity peak in the spring which is April/May in authors' study area, I suppose. The authors should be more precise when the vocalization has been recorded (months of the year, and hours of the day). It should be also mentioned that geographical variation in its vocalization is apparently low. Of cause, the authors have recorded and analyzed only the song. So, they should briefly provide in 'Introduction' the characteristics of the song (loudness, tempo, syllabs, colouration, duration etc.). Good examples of some sonographs from their study area should be included. This will not only improve the quality of the work but also its credibility. 

In figures, a line is indicated above some bars. I guess this is statistical difference: one dot indicates p<0.05, while two dots p<0.01. Please make it clear. Perhaps you should provide here details of the U-test, to make the results/comparisons more credible.                

Few technical suggestions:

-line 71: perhaps better to say 'species diversity in avian communities'

-line 82/83: it is not clear. It is ment here not one individual, but an array of species.

-line 92: For the clarity, give here a full English and Latin name of the species, and a note that from here onwards the 'Eurasian Nuthach' is simply 'nuthatch'.

-Fig. 1. It is not clear from where the four urban parks came. I guess that from the four dots to the left. Please make it clear.

-line 127: give here exact time

-line 243: 'different song' probably better to say 'songs with different characteristics'

-Fig. 3-6. I think it is better to refer the explanations (instead of repeat them) to the first figure (Fig. 3) where these are fully expalined. 

-Fig. 5, 6: Put first 'MMEFF' before expaining the abbreviation.         

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for clarifying and revising your manuscript. Your responses were thorough and appropriate.

Author Response

Comments and Suggestions for Authors: Thank you for clarifying and revising your manuscript. Your responses were thorough and appropriate.

Response: Thank you very much for your positive feedback and for acknowledging our efforts. We are glad that our revisions have met your expectations.

If you have any further comments or suggestions, please let us know. We are committed to ensuring the highest quality of our manuscript.

Best regards,

Qingming Wu

Author Response File: Author Response.docx