A Design Proposal for an Eco-Tunnel for Anurans Based on Behavioral Experiments and Species Characteristics
Round 1
Reviewer 1 Report
Wildlife crossing structures can reduce roadkills, amphibians commonly comprise the highest proportion of roadkills. Nevertheless, not enough wildlife crossing structures have been developed that are suitable for amphibian crossing. This manuscript provided a design proposal for amphibians WCSs based on behavioral experiments and species characteristics. I suggest this paper may be published in the journal after minor revisement. Some advises are following:
Abstract:
1. Line12, I think this study aimed to provide a design method or proposal, not a wildlife crossing structure.
2. Line19, what’s D700? I think it is “D700 (mm)”
Introduction:
1. Line36, wildlife crossing structures, this phrase has been used many times in this manuscript, please use “WCSs” to replace it in the following part of this manuscript.
2. Line66, now 18 WCSs aimed at amphibians have been installed in Korea? It’s good. So, what’s the successful experience and unsuccessful leassons from it? Maybe you can discuss it in the CONCLUSION?
Materials and Methods:
1. Line94-98, these contents may be deleted.
2. Line115, concerning low (0.1 points), how to understand it? It has not been used in Table 1.
3. Line140-141, I would like to know how to storage it at low temperatures?
4. Line152, Figure1? I can not find it in Figure 1.
5. Line175, I think this is not the experimental method, this is the description of each environmental factor.
6. Table2, as to the “Tunnel width”, you have not calculated and analyzed the degree of openness.
7. Table2, as to the “Construction meterial and Tunnel substrate”, I think the floor material and Tunnel substrate are similar conception, so I think these two factors are very similar.
Results:
1. Table3-9, these 7 tables maybe merged to one table, or move to the supplementary materials.
Conclusion:
1. Line 277-279. Based on the results of this study, noise reduction will not be a priority. I think this suggestion is not very good. According to my understanding, the impact of noise on the amphibians behavior and populations is very complicated, lots of studies proved the impacts are negative. This manuscript used the behavioral experiments with 50 individuals, although the results indicate the noise is not very important factor determining the movement of these 3 species, but I suggest the authors should be careful to make this conclusion.
Author Response
Daer. Reviewer
Please see the attachment.
We are very grateful for your comments, and we revised the manuscript following the suggestions. It was very helpful to enhance the quality of the manuscript.
Sincerely,
Authors
Author Response File: 
Author Response.doc
Reviewer 2 Report
Dear authors, thank you for this amazing study. It was a pleasure to read it. However, I have some issues that need to be addressed before acceptance for publication.
Firstly, I believe that some sentences need to be referenced.
Lines 26-27: Insert a reference for the first sentence
Lines 43-44: Insert a reference after "underwater beams"
Lines 59-60: Insert a reference after "human life"
Secondly, revise the entire manuscript and put the scientific names of the species in italics.
Thirdly, I would like you to revise the information in Table 2. I was a bit confused with the environmental factors "construction material" and "tunnel substrate". For me, their descriptions were switched. It is more understandable that PVC and concrete are construction materials and that soil, gravel, and concrete are the substrate of the tunnel. Please, revise this. If my interpretation is correct, then, some revision is needed on table 3 and table 7, as well.
Fourthly, I did not find the Discussion section. This is the first article without a discussion section that I revise. Is it correct?
Fifthly, I believe that more details are needed on the behavioral experiments. How long do they take? Were the amphibians released in the middle of the structure? How many individuals were released at each experiment? All 50 together? How they were moved to the experiment arena? There was a habituation period? How behavioral data were collected? Only the number of individuals that crossed the tunnels? Please, provide all information required for anyone to repeat your experiments.
Other minor comments:
Lines 113 and 116: Change IUNC to IUCN
Lines 116-118: And what about the score of 0.1? Did any species receive this score? If no, maybe it can be deleted from the text.
Table 1: change hgh to high on the first three lines of the first "roadkill" column
Line 145: Insert (Figure 1) after "unpredictable loss"
Line 152: Figure 2 instead of Figure 1
Line 176: Inster (Figure 3) after (Table 2).
Line 237: insert a space between "not" and "(Table 9).
Lines 286-287: How humidity was controlled or measured in your study? If this is an important factor, why it was not evaluated?
Author Response
Daer. Reviewer
Please see the attachment.
We are very grateful for your comments, and we revised the manuscript following the suggestions. It was very helpful to enhance the quality of the manuscript.
Sincerely,
Authors
Author Response File: Author Response.doc
Reviewer 3 Report
Dear authors and editor,
The article is fascinating and innovative I really liked it. It can be an important step in defining the best choice when constructing a wildlife passage for anurans. Congratulations to the authors for the experiments, they must have demanded a great amount of money, time, and effort. I made many suggestions, they are in the file attached, most of them are some details or more information that would improve the text comprehension.
The abstract and introduction are fine.
Some more information is needed in the sections animal capture and housing and experimental setting. See carefully my suggestions and questions.
In the section data analysis, it is necessary to perform a post-hoc test to state which groups differed from each other.
All figures and tables titles need to be more precise and bring more information. The reader should be capable of understanding it without having to go back to the text.
I don`t think tables 4 to 10 are necessary. The statistical results should come in the text, this would also provide a better reading experience. These tables can come as supplementary material.
The authors gave two subtitles for the section result, I don`t see the necessaty for this.
I think the authors could perform a final analysis considering all the species together and try to see if any pattern emerges. You could do it for the species that presented the same pattern across all three replications, in other words, for the species that the independence test was significant.
Conclusions are fine, but I think you could start telling the reader how awesome your study and results are. You mentioned the difficulty to design a single structure due to different animals' preferences, but your results are the opposite, you found a general pattern for the species, at least for those ones with significant results.
Once again, congratulations on this great job, I really hope my comments can help you.
Best regards,
Comments for author File: 
Comments.pdf
Author Response
Daer. Reviewer
Please see the attachment.
We are very grateful for your comments, and we revised the manuscript following the suggestions. It was very helpful to enhance the quality of the manuscript.
Sincerely,
Authors
Author Response File: Author Response.doc
Round 2
Reviewer 2 Report
Dear authors, thank you for clarifying your study. The paper is much stronger than the previous version. I believe that the paper is suitable for publication in Sustainability. A few minor corrections are still needed, however.
Please, find below my suggestions>
Abstract
Line 16: Specimens (50/species) were. I guess something is missing here.
Line 20: Change construction material by tunnel substrate
Introduction
Line 66: Change 14 by Fourteen
Lines 114-115: Please, complete the information. > 4% received the score 0.3. What about the scores 0.2 and 0.1?
Lines 123-124: insert a space between the parenthesis and the scientific names of the species
Methods
Line 136: housed instead of housing
Lines 144-145: insert a space between the parenthesis and the previous words
Discussion and Conclusion
Lines 298-299: Insert a reference at the end of this sentence
Figures and Tables: Please, delete the date of the experiment. It is not necessary.
Author Response
Daer. Reviewer
Please see the attachment.
We appreciate checking carefully and giving us suggestions. We revised all parts of the manuscript following the suggestions. It was very helpful to enhance the quality of the manuscript.
Sincerely,
Authors
Author Response File: Author Response.docx
