Annual Dynamics of Bird Community at a Coastal Wetland and Their Relation to Habitat Types: The Example of Beidagang Wetland, Northern China

Round 1

Reviewer 1 Report

This is a descriptive study presenting the results of surveys of wetland birds at Beidagang Wetland Nature Reserve in northern China, over a five-year period, from 2015 to 2019. The authors describe the abundance of birds and number of species according to ecotypes, bird orders and threat categories. It is obvious that a lot of work went into this study and a lot of data was collected (bird counts once /month for 5 years). Also, the study is relevant for the conservation of an important wetland (Beidagang Wetland) and threatened and endangered bird species. However,

(1) The text needs to be re-written. The manuscript should be corrected by a native English-speaker as there are many language errors and information is not clear. Extensive editing of the English language and style are required. 

(2) Data analyses, presentation of results and discussion are a bit basic considering the huge amount of data that was collected. They need to be re-written with more detail and additional data analyses. 

(3) Relevant information is missing. 

For example, in the Materials and Methods: 

What type of wetland is Beidagang Wetland (freshwater, brakish, lagoon? etc)

How many sites were surveyed?

What types of habitats were surveyed, what area did each habitat cover?

The section on Data Processing should explain what statistical tests were used

In the Results section, why are numbers pooled per 6 months? Why not monthly? Some explanation required.

Figure legends are incomplete.

A Table showing which bird species belong to each group (terrestrial birds, birds of prey, climbing birds, songbirds, wading birds, swimming birds) should be included.

Statistical tests are missing, for example in the dynamics of bird communities (starting at line 107), numbers are mentioned without any statistical analyses. This is the same in other sections too.  

The Discussion should also be enriched and improved. Overall, the manuscript needs to be re-written with clearer and more comprehensive information, also regarding the relevance of the study to the conservation of this wetland, and threatened and endangered bird species.

Therefore, bearing in mind the amount of work that went into this study, and the substantial dataset that was collected, I suggest to reconsider after a major revision. 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

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Comments for author File: Comments.pdf

Author Response

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Reviewer 3 Report

Introduction: The introduction is well-written, and the framework allows the understanding on which is the topic that will be researched in the manuscript. I don't have change suggestions.

Methods: The bird survey methods described here do not allow to survey of terrestrial birds (eventually raptors). It should use point counts or transects. Also, the section "Data processing". In this section, you should state clearly which variables you related, to obtain which relationships, and with which R packages (the R version is not enough). As it is now, the article is not replicable.

Results: Figures presented are quite unclear (see specific comments), and my comments are mostly based on the text. As a result of the method, the most abundant birds were swimming birds, but with this type of survey, you probably did not detect most of the passerines. You should correct this method (or assume the bias for passerines). This applies only to the Abundance, I think the analyses on richness are fine.

Discussion: You should rather say if the types of land were "related", and how were related. For example, now it says "Building land was significantly related with wading birds and birds of GRUIFORMES". It should say if was a positive or negative relationship.

General format: I'm not sure is correct to mention the "Orders" with captions (e.g., GRUIFORMES), but check which are the journal rules and follow their requirements.

English: English is mostly fine. Only is a bit wordy in some sections (e.g., Building land was significantly related to wading birds and birds of GRUIFORMES). 

Figures: The caption should include more information, for making the figure self-explanatory. It should show information on the topic developed in the article. All of them are too short and don't provide enough information. Further, some figures could be merged, and the current figures sent to supplementary material since right now there is an excess of details (and the figures are too small, so it is not possible to read them properly)

Figure 2: It is not clear what FH and SH mean. Also, the abundance of birds that are not swimming birds is not clear and is hard to compare the abundance between years for songbirds for example. An option is to show the graph in a logarithmic scale, to correct this?

Figure 3: Labels on the Y axis 

Figure 4: Same comment as Figure 2. Species of Least concern make it hard to understand trends for the other species.

Figure 5: This figure is repetitive. I would rather suggest including a seasonal analysis to understand the phenology of the birds, and when they visit the wetland.

Figure 6: This figure is quite confusing because you did not explain them in methods and the caption is poor. What are levels? What is NMDS1? etc.

Figures 7-9: It is not clear what you did here... Explain it in methods

 

Minor corrections:

L85: Replace survey with surveys

L174: Replace Compositoin by Composition

L183: It is unclear how you built these GAMMs. Please, add this information to the methods.

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

As mentioned in a previous review of this manuscript, this is a descriptive study presenting the results of surveys of wetland birds at Beidagang Wetland Nature Reserve in northern China, from 2015 to 2019. The authors describe the abundance of birds and number of species according to ecotypes, bird orders and threat categories.

 While the authors have made an effort to address previous comments on this manuscript,

(1) More extensive editing of the English language and style are required. There are major language errors, such as incorrect singular-plural forms and past-present tenses. Also, the information is confusing at some points and needs clarification.  

(2) This is a descriptive study consisting of annual bird counts in relation to available habitats and habitat fragmentation. This is a simple concept, and as such, the manuscript needs to be simplified accordingly. Data analyses and presentation of results are not entirely clear and need to be simplified. The results should focus on the statistically relevant results. There is no need to provide lists of numbers for non-significant results, also all results should be easy to find by looking at the Figures. Figures should be simplified by presenting data from full years, since half-year data does not differ significantly. More suggestions about Figures are mentioned in the relevant sections. Also, since the manuscript is dealing with habitat and habitat fragmentation, it would be interesting to see a map (or maps) showing habitat distributions at the study area.   

(3) The discussion is quite basic considering the large amount of data that was collected. For example, explanations about changes in annual abundances of bird communities and ecotypes are incomplete. What about rainfall and temperature? Don’t these influence annual abundances of the birds? What were the weather conditions like during the duration of the study? Is climate change having any effect? Concerning ecotypes, doesn’t it make sense that swimming and wading birds are the most dominant ecotypes at a wetland? Also, are there many shrubs and trees at the wetland that would explain the numbers of songbirds?  

(4) Overall, in the Discussion and Conclusions it would be relevant to include more specific recommendations for bird conservation, targeting specific ecotypes and/or bird species. As such, the discussion is quite general. 

Lines 2&3: The title is not correct grammatically. It should be rephrased. For example: Annual Dynamics of Bird Communities at a Coastal Wetland and their Relation to Habitat Types: the example of Beidagang Wetland, northern China, 2015-2019

Lines 14-27: The Abstract needs a general statement about the overall importance of the study. It should also include information about the methodology followed.

Lines 82 & 83: what are first-class and second-class national protected animals? This needs to be explained

Line 87: Figure 1. The legend is incomplete. Is the red line the boundaries of the wetland?

Line 92: were the 35 sites picked randomly?

Lines 92-93: It is stated that ‘The survey regions involved open water, reed meadows and perennial grasslands, etc.’ Delete ‘etc’ and mention all the habitat types.

In Line 115 it is mentioned that 'the area of each habitat type was estimated annually'. In Lines 119-121, the area of each habitat in 2015 is mentioned. What about the following years? If there was a substantial change, either include the information in a Table or show it in a map or maps. Specially since the paper is focusing on habitat types and fragmentation.

Lines 123-125: It is not necessary to explain where ANOVA is used. Only what was tested  in the current study.

Lines 128-130: Similarly, it is not necessary to explain where NMDS is used. Only what was tested in the current study.

Lines 140-141:Similarly, it is not necessary to explain where the Mantel Test is used. Only what was tested in the current study.

Line 144: The information from Section 2.5 should be incorporated in Section 2.4.

Line 153: should be Communities

Lines 156 & 157: what do these numbers refer to? If it’s individuals, it should be stated, throughout the manuscript.

Lines 155 to 167: Were these differences statistically significant? If not, it is better not to mention them because the information becomes too confusing

Lines 168 & 169: Why are just the swimming birds mentioned. It’s better to delete this sentence and improve Figure 2 (see below) so that it becomes easy to find all  information from the graphs.

Figure 2: If there are no significant differences between half years, I suggest to present graphs showing full years in Figure 2. 

Lines 184-196: This information cannot be understood by looking at Figure 3. The results need to be simplified. Again, I suggest to present the graphs showing data from full years (since semi-years do not differ significantly, according to Table 2)

Figure 5: It would be clearer to present the information as a bar chart as it will be easier to understand how many birds were counted each year. Also, the legend should be more concise: Total number of birds counted annually

Also, include a Figure presenting in a bar-chart the total number of species counted annually

Lines 236-246: The information is confusing. I suggest to delete Figures 6-9 that are not easily understandable (Figures are supposed to provide an easily assimilable summary of results, but these do not), and include a map (or maps) showing the distribution of habitats and the extent of habitat fragmentation during this study

Line 286: this is a very basic conclusion, considering all the fieldwork that took place in this study

Line 305 it is stated that ‘building land can positively influence wading birds’ while Line 315 states that ‘wading birds were significantly impacted by building land’. Please correct the information.

In Line 334 it is stated that ‘In the future, other factors affecting bird community should be looked into.’ Such as? Mention some suggestions.

 

 

Author Response

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Reviewer 2 Report

You have addressed most of the issues that I raised fairly adequately, particularly with respect to the need for a description of the survey mewthods and statistical analyses.

Author Response

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Reviewer 3 Report

Dear authors,

Thanks for your effort of improving your manuscript. The new version is much clearer now.

 

I think there are two issues now:

The first is that, as I stated in the first review, the survey methods are not appropriate to quantify the abundance of populations of raptors and songbirds (despite they were recorded). It is a mistake, and at least should be included in the discussion. Please, check Ralph et al. (1995) or more recent literature to indicate that the abundance of songbirds is probably underestimated in this study.

 

The second issue is the name of the orders with capitals. If the authors insist in keeping the names in capitals, at least give more space in the Y axis in the figure 2 and eliminate the labels on the right (the information is duplicated)

 

Best regards,

Author Response

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