Land Sparing Can Maintain Bird Diversity in Northeastern Bangladesh

Round 1

Reviewer 1 Report

Dear authors, 

i have made substantial comments in the attached pdf. i suggest restructuring the introduction, rewriting the methods with more explanation about the bird surveys (flying over or using the habitat, detected by sound or sight, general biases etc). why did you decide for only one survey at a site? how would this affect detectability? nocturnal species? non-vocalizing species? once a day or once in the morning and once in the afternoon? you say "This often made accurate identification quite difficult." so how can we trust the results? was it the same bias in both habitat types?

how many species were only heard/only seen/both in both land types? how can you make sure that based on one visit you are not interpreting bias as a result? needs a section about this. is it possible that the visibility/vocalization of the species differs between the two types? are you counting birds that use the habitat or just fly over? all of these issues need to be addressed

what makes some species indicator (table 2) compared to the other birds? need to describe in methods

also need better discussion of the differences in habitat structure etc. would be good to see a table with height of species, complexity, native etc.... also, you need to rewrite the discussion. a lot of statements are thrown in the discussion without any base or citation.

line 240 so these issues would be present within land-sharing areas too? are the differences a consequence of habitat structure or some crops are not possible to grow under both conditions? need to be explained.

where you bring up if it works in other countries - it needs much more explanation as i explain in my notes

i disagree with the whole section from 250 as explained in the text

line 263 you have not measured diversity of habitat or food resources, right? so this statement needs to be supported by literature and you need to convince the reader that the results are originating form sampling bias

in the end of the discussion /conclusion you need to talk about how much land do you need for agriculture in both scenarios (much higher for land sharing) so with increasing food production native vegetation will be converted to land sharing. see the literature about trade offs

see the attached document for more comments

 

Comments for author File: Comments.pdf

Author Response

"Please see the attachment."

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors, it is a nice work.

Please, within experimental design, specify more clearly, if land-sparing sites were located in protected areas (lines 151,152), as it is described in Introduction, lines 55-57.

What is the % of protected areas versus farmlands on the experimental territory?

Within chapter 3.1 Abundance:

In land-sharing sites, average numbers of individuals = 6.8, SD=4,2, that means coefficient of variation is 61.7%. The same for land-sparing sites, coefficient of variation is 56.3%. Can you comment this very high degree of variability? The same for Shanon diversity values.

Author Response

"Please see the attachment"

Author Response File: Author Response.docx

Reviewer 3 Report

One of the most significant sustainability challenges facing humanity is the need to balance food demand with conservation of biodiversity. Land use decisions play a major role in determining this balance. Here, the authors compared bird species diversity and abundance in land sharing and land sparing sites in northeastern Bangladesh. Greater diversity and abundance were found in the land sparing areas which the authors believe was largely explained by the greater availability of food and decreased use of chemical fertilizers relative to land sharing sites. Although land sharing is more effective at producing food, land sparing is shown to be more effective at preserving bird diversity in the study area.

 

Introduction is clear, thorough, and effective at presenting the context and importance of the research. Linking the importance to global issues such as climate change makes the relevance clear. Expectations and hypothesis are made clear.

 

Materials and Methods - the study area is described effectively, particularly the important differences between land sparing and land sharing in the local context with relevance to the study. Study methods are described and justified clearly.

 

Results are presented clearly and the case for land sparing supporting higher bird biodiversity and abundance than land sharing is made in a number of effective ways.

 

The Discussion addresses the wider context and implications of the findings and looks at specific issues around individual species that did or did not fit with the broad results. The findings are effectively linked in to the larger global context. The vulnerability of Bangladesh in particular to climate change and sea level rise is pointed out, along with the threat that these pose to food security which may in turn have knock-on effects to land management practices such as those studied here.

 

The Conclusion is effective at summarising the results of the study and its relevance to the difficult land management decisions Bangladesh is faced with given rising food security concerns. In particular the paper ends on a note of recommending that three bird species be used as indicators of biodiversity in land management decisions, which is a useful and targeted piece of advice.

 

Overall I feel that the paper reads very well, presents all necessary information very clearly and effectively, and that the research is both sound and relevant.

Author Response

"Please see the attachment."

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

dear authors, thank you for revising the manuscript. while it has improved, it still needs some reorganization (methods and discussion) as well as thorough editing as mentioned during the last round. please see my detailed comments in the attached pdf.

Comments for author File: Comments.pdf

Author Response

"Please see the attachment."

Author Response File: Author Response.docx