Trophic Relationships Between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in High-Mountain Grasslands During the Summer Season

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

General Comments:

Interesting manuscript regarding the food resource utilization of three species of animals in a high mountain Chilean grassland. While likely well-conducted, there are many missing elements in the manuscript, including a clear motivation for the study, specific methods and details in the results.

Firstly, the use of the word ‘trophic’ in the title should likely be changed, as it implies competition or other interactions between the participants, which has not been included.

Secondly, the abstract is unclear, especially lines 11-14, as there is no direct separation of the introduction, methods, results and conclusion within the abstract, but almost only results. As such the abstract needs to be rewritten to have a clearer structure.

Thirdly, from the introduction it is not entirely clear to the reviewer why this study was needed. Animals have resource utilization that might overlap, we know this. Why these particular animals, ecosystems or resources? Is there a particular concern regarding unsustainable use or competition between natural populations and human activity via domesticated animals? This must be made much clearer.

Fourthly, very little information is present about the plant diversity, and how it relates to the diet of the animals or the ecosystem. The authors talk in passing about plant species groups but that is about it. Much more info is required about the plant diversity and its variation and then presented as part of the results.

Lastly, there is missing information regarding the proportion of resources in the ecosystem and what was actually there. If 95% of the vegetation were graminoids it would make a lot of sense that it constitutes a majority of the diets of the animals feeding there. Yet much of this relationship between the plants and the ecosystem is missing.

To conclude, the authors must specify their motivations, methods and result to a much greater extent, as currently there are a lot of information missing that are required to properly interpret the manuscript, its findings and the conclusion given by the authors.

Specific Comments:

1. Lines 31-33. What do the authors mean here with ‘natural or altered’? Every single ecosystem on the plant is either natural or altered, as such it does not make a lot of sense.
2. Lines 67-68. Much more information is required regarding these plant inventories, including how many plots per site, size of plots, inventory methodology, limited to which species groups, motivation of conducting it during March etc.
3. Lines 85-87. First time a transect is mentioned, with the reader having no idea of what type of transect was used, why or in which context.
4. Lines 87-91. More information required regarding how the dry matter was removed and what constitutes as dry matter, as it could include all vegetation within each area, meaning that only soil would be left after the harvesting. This implies that only vegetation germinated from seed from that season would be present at the end of the season.
5. Lines 94-96. Do the authors mean transect here? Also, what is the width of this transect? Also, specify what you mean with ‘sectors’, and how you determine if they were representative or not.
6. Lines 117-119. Should be clarified further. How do the samples relate to the sub-samples, per herbivore and per animal species? Perhaps it can be rewritten for additional clarity or represented graphically in the supplementary material if it cannot be written clearly.
7. Lines 125-127. Are all the plants equally likely of being preserved and identified within the samples? If not, then the known composition and method is likely to be representative.
8. Lines 128-130. Can you tell small residues of annual and perennial grasses apart in faecal samples?
9. Lines 173-177. Do you know for certain that the diet was obtained from the same patch the faecal sample was collected at? It is entirely possible that the diet was obtained elsewhere, and the faecal samples were deposited on a completely different site. Without observations of foraging, you cannot say for sure.
10. Lines 216-218. What do you mean with ‘indicator species’ here? What do they indicate? Are not these two species just the most common / dominant species in the area?

Figures and Tables:

1. Figure 1. The authors should add a third map containing the zoomed red-square study site.
2. Figure 5. Is this equation relationship correct?

Comments on the Quality of English Language

Parts of the manuscripts would benefit from additional proof-reading, as some sections are difficult to understand with some issues regarding spelling and sentence-structure.

Author Response

Dear reviewer

we have  gone over your comments and reviews. We are grateful for your insights and our replies are on the PDF file attached to this reply.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

you have some modification in your ms.
the list of reference is not correcte & update it.

 

Best regards ...

 

Comments for author File: Comments.pdf

Author Response

Dear reviewer

we have  gone over your comments and reviews. We are grateful for your insights and our replies are on the PDF file attached to this reply.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript discusses the trophic relationships between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in high mountain grasslands during the summer season.

Some points are raised below. All answers should be included in the revised version.

1. Please, explain the selection of these three particular herbivores.
2. 173-7: further explanation is needed.
3. Figure 5: please, explain the findings therein
4. 240-6: The passage is not in line with Figure 7; please, check.
5. Also, figure 7: Explain the linear and non-linear behaviors. Does the mathematical function type show anything?

Author Response

Dear reviewer

we have  gone over your comments and reviews. We are grateful for your insights and our replies are on the PDF file attached to this reply.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The title of the paper effectively reflects the article's content.

The paper addresses the interesting and topical issue of trophic interactions in complex high-mountain ecosystems, focusing on the shared feeding habits of three herbivorous vertebrate species. The authors attempt to link vegetation characteristics with the uniformity and overlap of the diets of the studied species, which is essential for understanding competition for resources in ecosystems subject to anthropogenic pressure.

The study makes a valuable contribution to trophic and foraging ecology and may be relevant to grazing management practices in the mountainous regions of Chile. The work is well anchored in the literature, and the methodology is described reliably and comprehensively.

The abstract is sufficient without unnecessary generalisations and focuses on the valuable points of the manuscript.

The Introduction chapter effectively introduces the reader to the study's topic and clearly states its purpose.

The material and methods are well described. The authors skilfully combine data on vegetation composition with trophic data, which increases the interpretative value of the results. Transparent methodology for collecting field data (transects, plots, microhistological analysis). The use of the J(d) and O(Pianka) indices is appropriate and well justified. (as confirmed by the literature).

The graphs in the paper are well chosen and clearly illustrate key relationships. They enable a quick comparison of dietary diversity and the relationship between the availability and consumption of plants, providing a visual insight into the degree of overlap between food niches. Their form – mainly bar charts, scatter plots, and non-linear relationships – is well-suited to the nature of the ecological data. Correlation charts are particularly valuable, as they reveal complex relationships that are not obvious from tabular analysis alone. The use of statistical analysis of variance (ANOVA) and post-hoc tests (Tukey) is correct.

The bibliography is extensive and up-to-date. Selection of sources

 correct: 42 literature items were used in the study. The items in the literature list were appropriately selected to cover the subject matter.

The discussion is extensive and appropriately guided.

The conclusions are accurate and well supported by data and statistics. The authors are cautious in their interpretation (e.g., they discuss ‘potential’ competition), which is a significant advantage. One could add another paragraph about practical implications (e.g. for grazing management in the mountains). However, this is not a criticism, but a suggestion for the authors, who do not have to respond to it. In my opinion, the work is very valuable and well-written. I believe it is suitable for publication in Ecologies without significant revisions.

Author Response

Dear reviewer

we have  gone over your comments and reviews. We are grateful for your insights and our replies are on the PDF file attached to this reply.

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

Dear authors,

This article concerns “Trophic relationships between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in high mountain grasslands during the summer season”, by Giorgio Castellaro G., Carla Orellana M.; Juan Pablo Escanilla C. and Claudia Navarro. It has to be noted that apparently it is already published in Preprints.org (www.preprints.org) | NOT PEER-REVIEWED | Posted: Posted: 23 May 2025 doi:10.20944/preprints202505.1863.v1. As interesting and quite rare data (especially for Thinocorus orbignyanus), I may recommend it for an international audience in this journal, however several points have to be considered by the authors and a major revision is requested.

 

Please notice that in order to bring a broad audience to this article and to this journal, for specialists and non-specialists, the six points of my comments (at the beginning) are very important (mandatory…) for a suitable value of the article. Minor points are also enhanced at the end of this review.

 

Sincerely yours,

 

The six major points are:

• 1 The main point embarrassing me a lot concerns the number of samples used in this study. The number of feces should be indicated more precisely (“between 15 to 20 samples per herbivore, consisted of a set of 10 to 15 fresh sub-samples from each animal species” is far not enough precise; please consider that data homogeneity makes the robustness of your study (normally 30 is required for statistical evaluations like t student test), a too low number for one sample has a lower weight. Moreover, in 2.3, clarify "by evaluating 31 20 m transepts".
• 2 In order to understand better the selection of species by these three animals, the total composition of the vegetation(s) is needed and its variability (?) among the different sites (as supplementary material provide adequate lists and indexes as noticed in material and methods).
• 3 Some elements are rather obscure: 1/ The types of fragments in the feces should be precised (leaf, stem, root, seeds or equivalents), it may influence the differences of percentages in the feces, at least it has to be inserted in the discussion part; 2/ I am surprised that the volume of feces (and the putative competition between the animals) is not involved (?) in the results and/or discussion, as actually the quantity of food of a horse is not that of a bird or a hase.
• 4 References already taken in account by the authors are of interest, however checking in the web of science and scilit from mdpi the number of references is rather low (for instance the relationship sensu lato between horse and rabbit-hase is studied), especially for recent references which are not so abundant in your selection. All these should be updated and used (if relevant for comparisons, techniques…) in order to sustain much more and provide a larger view of these researches. Among papers are the followings:

[1-8]

1. Reus, M.L.; Cappa, F.M.; Andino, N.; Campos, V.E.; Ríos, C.d.L.; Campos, C.M. Trophic interactions between the native guanaco (Lama guanicoe) and the exotic donkey (Equus asinus) in the hyper-arid Monte desert (Ischigualasto Park, Argentina). Studies on Neotropical Fauna and Environment 2014, 49.

 

2. Abaturov, B.D.; Kazmin, V.D.; Kolesnikov, M.P. Nutrition of bison (Bison bison), camels (Сamelus bactrianus), and horses (Equus caballus) from their joint grazing on an isolated steppe pasture. Biology Bulletin 2016, 43.

 

3. Durán-Antonio, J.; González-Romero, A.; Sosa, V.J. Activity overlap of carnivores, their potential wild prey, and temporal segregation, with livestock in a Biosphere Reserve in the Chihuahuan Desert. Journal of Mammalogy 2020, 101.

 

 

 

4. Bobadilla, S.Y.; Dacar, M.A.; Jaksic, F.M.; Ojeda, R.A.; Cuevas, M.F. Spatial and trophic niche of an assemblage of native and non-native herbivores of arid Argentina. Journal of Mammalogy 2022, 103.

 

5. Kassa, Y.; Tekalign, W. The Population Size and Distribution of Diurnal Large Wild Mammals in the Southern Great Rift Valley, Ethiopia. The Scientific World Journal 2022, 2022.

 

 

6. Wild, M.; Gauly, M.; Zanon, T.; Isselstein, J.; Komainda, M. Tracking free-ranging sheep to evaluate interrelations between selective grazing, movement patterns and the botanical composition of alpine summer pastures in northern Italy. Pastoralism 2023, 13.

 

7. Maierdiyali, A.; Wang, Y.; Yang, Y.; Chen, J.; Tao, S.; Kong, Y.; Lu, Z. Experimental study on improving the utilization rate of underpasses of bundled linear infrastructure on Tibetan Plateau. Nature Conservation 2024, 57.

 

8. Peyton, M.A.; Garrison, S.R.; Passernig, R.B.; Suazo, M.M.; Parmenter, R.R. Early successional changes in coniferous forest small mammal communities following a high‐severity summer wildfire. Ecosphere 2025, 16.

 

• 5 Although I am not a native english speaker, the english writing suffers from many mistakes in syntax and grammar (e.g. “While correlation the abundance of two”, “to which an exponential decline model could be adjusted”, “Argentine” in 4.), the whole text has to be read and corrected by a specialist.

 

• 6 Some points of terminology have to be clarified, providing a clear definition of "patch" and “samples-subsamples”, which are very obscure in the present version.

 

Minor points are:

1 As I am involved in taxonomy I am very sensible to correct taxa names which make their homogeneity and precision at the international level, which are not (at all…) respected in the present text (e.g. “Lepus europaeus” in italics in 3.4). The latin name of each taxon (in italics) plus the author(s) (not in italics) have to be inserted (at least) the first time they appear in the text (from the beginning of the introduction). Use international Plant Names Index (IPNI) https://www.ipni.org/ or equivalent for plants, use zoobank.org or equivalent for animals.

 

2 As it is a submission in an ecology journal, photos of the animals and plants seem necessary, especially for the rare Thinocorus.

 

3 In material and methods, there are two 2.3.

Comments on the Quality of English Language

Although I am not a native english speaker, the english writing suffers from many mistakes in syntax and grammar (e.g. “While correlation the abundance of two”, “to which an exponential decline model could be adjusted”, “Argentine” in 4.), the whole text has to be read and corrected by a specialist.

Author Response

Dear reviewer

we have  gone over your comments and reviews. We are grateful for your insights and our replies are on the PDF file attached to this reply.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

General Comments:

The authors have acceptably responded to the reviewer’s comments and amended the manuscript accordingly.

Author Response

The responses were already submitted in round 1, and according to your new report, they were accepted...

Thank you very much for your valuable suggestions.

Reviewer 5 Report

Comments and Suggestions for Authors

Dear authors,

Good morning, I read this second version with interest, however still some very important points have to be clarified.

Yours sincerely,

 

1 Concerning the answer 1, the number of feces per animal is still unclear: checking in the article 3 referenced in the new text part, I cannot find the answer (“we have determined”) in the two places where “feces” appear (one of them being “collecting as many fresh feces samples as possible of horses (n = 17 in the 2011 season; n = 18 in the 2012 season), guanacos (n = 15 in the 2011 season; n = 12, in the 2012 season), and hares (n = 15 in the 2011 season; n =18inthe 2012 season)”). Moreover I wonder if the statistical tests are relevant for these heterogeneous and rather low in number data (figures 4-8), for instance for Pearson correlations indicated in material and methods a minimum of 25 is mainly evocated by statistics authors (see also for instance Pearson, Kendall and Spearman correlations, Psychometrika, 65(1), 23-2). I wonder if statistical tests with low number of data, as some do exist, could be more relevant (?).

 

3 For point 3, since “ evaluating a possible interspecific competition between them” is now in the abstract, the volume of food taken by each animal (directly related with competition between these very different animals) has to be enhanced somewhere in the discussion.

 

5 For point 5, I requested clearly in my comments a revision of the “whole text”, not only of the few parts corrected by the authors.

 

6 For my point 6: 1/ since you are supposed to investigate a homogeneous vegetation (?), your sentence with “differs” is not understandable (“understanding the latter as a discrete and homogeneous area of vegetation that differs from its surrounding environment”).

 

Please reword “traversal” in 2.4 (= transversal?)

Comments on the Quality of English Language

I requested clearly in my first comments a revision of the “whole text”, not only of the few parts corrected by the authors.

 

 

Author Response

1 Concerning the answer 1, the number of feces per animal is still unclear: checking in the article 3 referenced in the new text part, I cannot find the answer (“we have determined”) in the two places where “feces” appear (one of them being “collecting as many fresh feces samples as possible of horses (n = 17 in the 2011 season; n = 18 in the 2012 season), guanacos (n = 15 in the 2011 season; n = 12, in the 2012 season), and hares (n = 15 in the 2011 season; n =18inthe 2012 season)”). Moreover I wonder if the statistical tests are relevant for these heterogeneous and rather low in number data (figures 4-8), for instance for Pearson correlations indicated in material and methods a minimum of 25 is mainly evocated by statistics authors (see also for instance Pearson, Kendall and Spearman correlations, Psychometrika, 65(1), 23-2). I wonder if statistical tests with low number of data, as some do exist, could be more relevant (?).

R: We agree with reviewer 5 that the number of samples collected in our study was small, but it is what we were able to gather in the field campaigns conducted, given the logistical and environmental limitations we faced (Since the study was observational, we were unable to establish a precise number of samples, and therefore we could not consider the same number of fecal samples for each herbivore evaluated. In other words, we collected what we found on our route). Despite this, our statistical analyses achieved significance, allowing us to make inferences. We opted to calculate the Pearson correlation, since despite the limited data, they presented normality. The calculated correlations and regressions were significant in most cases, as indicated by the p value attached to the graphs. When they were not, this was mentioned in the text with reference to the obtained p value.

 

3 For point 3, since “ evaluating a possible interspecific competition between them” is now in the abstract, the volume of food taken by each animal (directly related with competition between these very different animals) has to be enhanced somewhere in the discussion.

R: We have expanded the discussion by pointing out that the degree of potential trophic competition is not only determined by dietary overlap but that other variables also determine its magnitude. Citations in this regard have been added [cites N° 51; 52; 53].

 

 

 

5 For point 5, I requested clearly in my comments a revision of the “whole text”, not only of the few parts corrected by the authors.

R: We partially agree with your comment, since we accepted your suggestions, we have responded point by point to the observations in our new manuscript. We consider these observations to be quite a few and, of course, we appreciate them.

• Many of the observations made by Reviewer 5, especially those related to the number of observations, are consistent with those of Reviewer 1.
• The reference to the type of fragments in the feces was clarified. The reference to the volume of feces, an aspect not measured in our study, was also mentioned in the previous response.
• We have incorporated new citations into the work highlighted in purple.
• We have revised the English and the nomenclature of the scientific names.
• We have incorporated photographs of Thinocorus.
• The numbering of the Materials and Methods section has been corrected.
• The discussion has been expanded by incorporating three new references

For all the points mentioned above, we believe we have carried out a complete review of the manuscript, incorporating the suggestions of reviewer 5, as well as those of the other four reviewers.

6 For my point 6: 1/ since you are supposed to investigate a homogeneous vegetation (?), your sentence with “differs” is not understandable (“understanding the latter as a discrete and homogeneous area of vegetation that differs from its surrounding environment”).

5. according to the reference N°10) (Laca, E. A., G. Lemaire. Measuring Sward structure. Chap. 5. pp 103-122. In: L. ‘t Mannetje; R.M. Jones Eds. Field and Laboratory Methods for Grassland and Animal Production. CABI Publishing. 447 p.) that is the concept of “vegetation patch”. The vegetation patch is relatively homogeneous, but it is very different from the vegetation that surrounds it. In general, the wet grassland (vegas) corresponds to an azonal vegetation, which grows in hydromorphic soils located in depressions and differ substantially from the zonal vegetation that surrounds it.

 

 Please reword “traversal” in 2.4 (= transversal?)

R: The new manuscript explains that the route through the wet grassland was a "cross country" type route.

 

All corrections in the new manuscript (Round 2) are written in bold type highlighted in yellow.

Author Response File: Author Response.pdf

Round 3

Reviewer 5 Report

Comments and Suggestions for Authors

Dear authors,

 

I read this new version, however since mainly my point 1 is still very unclear (not argumented or answered precisely) I have to maintain it. I am sorry but this submission is very unfortunately definitely not receivable. As a smaller point, I requested in my first review an English revision of the whole text, the answer (point 5) or the authors does not correspond to my English request.  

Comments on the Quality of English Language

As a smaller point, I requested in my first review an English revision of the whole text, the answer (point 5) or the authors does not correspond to my English request.