Macroecology of North European Wet Grassland Landscapes: Habitat Quality, Waders, Avian Predators and Nest Predation

Round 1

Reviewer 1 Report

Dear Authors,

Thanks for this research on effects of predators on populations of waders.

Please find here below few suggestions for further improvement of presented paper.

Introduction
If wet grasslands are presented as cultural lanscapes extended by humans, explanation should be provided why e.g. land abandonment or forest expansion - i.e. natural processes - are considered drivers of grassland degradation. Rather terms natural conversion or succession should be used than degradation for such cases.

Figure 1 - colour coding for Avian predator pressure trend is strange. The location of Attempt to restore at the axis is confusing - term should be explained.

Methods
L217 Meaning of xx should be explained.

Results
L263 Please explain landscape gradient.
L273 and Fig. 4. The category unknown is quite high at 43% suggesting limitations of used methodology.

Fig. 5 - Check grammar of the caption.

Dicussion
L309-311 Please check and update statement on predators to waders decrease from emerging (functioning) to degraded in line with data presented in Table 2.

L316,  Please consider to mention also other factors than the intensity of landscape use as the reasons of predator population abundance were not subject of this study.

L324 - The context of corvids being well suited to landscape intensification should be better discussed and described in relation to investigated study areas. 

Conclusions
L422 - 433 Impact of habitat quality was not subject of this paper.

Author Response

Please see the attachment and thank you for the constructive review. 

Author Response File: Author Response.pdf

Reviewer 2 Report

This study selected six wet grassland landscapes representing a gradient in both grassland habitat development and breeding wader population status to test the hypothesis that the anthropogenic developmental stage of wet grassland habitats and landscapes drives avian nest predator abundance, and thus the predation pressure on nests, which is a major cause of wader bird declines.  Overall, the manuscript is well written.  I only have one suggestion: it is better to objectively quantify the degradation levels of six sites instead of subjective description.

Author Response

Dear reviewer 2,

Thank you for your positive review. In regards to your only suggestion. "it is better to objectively quantify the degradation levels of six sites instead of subjective description." We think we have done this, however we have also added a sentence to each case study are to justify their selection.

Thank you for your help.

Reviewer 3 Report

I appreciated the opportunity to review your manuscript. I added more specific comments on the attached ms copy. I found several issues that caused me to question the validity of your study:

1. You have many terminology/conceptual issues, which translate into a flawed study approach (see comments on text).
2. The study design is inappropriate for the question being asked, primarily because you sampled from across such a broad geographic extent AND selected a range of degraded sites; you knew what the outcome would be.
3. You only visited each location once per year, which is far below any acceptable standard.
4. You used a simplistic analytical approach (correlation) that ignored all of the confounding variables and potential covariates.
5. Your artificial nest/egg experiment is really problematic. You ignored the substantial literature that shows the many flaws with this approach.

I am not really sure how to fix any of these major problems. I am usually pretty good and figuring out how to suggest ways around a problematic design and sampling methodology, but I am at a loss here. You should have gathered strong data from a much narrower geographic area. Hopefully another referee can be more helpful.

Comments for author File: Comments.pdf

Author Response

Please see the attachment. Thank you for the review. 

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The authors basically either rejected or only made minor changes based on my previous comments. The data set is inadequate (they insist a single observation is adequate!). I seldom encounter authors who refuse to step back and see the weaknesses in their work and make substantial adjustments. But here we are.

Author Response

Dear Author 3,

We would just like to thank you again for review. Your comments were considered and have helped improve our manuscript.

 

All the best