Avian Responses to Different Grazing Management Practices in Neotropical Temperate Grasslands: A Meta-Analysis

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

The detail added by the authors regarding the methodological approaches used, information about the study system, and conservation implications of the study significantly improved the manuscript. I note additional minor comments below.

 

Simple summary/Abstract

·      “negatively impacts” instead of “impacts negatively”

Introduction

·      “used in the Rio de la Plata Grasslands” instead of “involved”

·      “To address these issues,” – to address them for whom, or for what? Suggest making this sentence and the next sentence more specific. E.g., who developed the technologies, and who is using them?

·      “EPM aims” instead of “EPM aim”

·      “desired” grass species? Or all types of plants? And desired by whom – ranchers? Does “desired” mean native, or could non-native plant species be desired?

Materials and methods

2.1

·      “…and is highly interannually variable.” Instead of “present high interannual variability”

2.2

·      I’m not sure what is meant by “sample size for each grazing management”.

·      What are “appropriate” treatment comparisons – are they the ones that aligned with the treatments focused on in this study? Suggest being more specific.

2.3

·      Suggest removing comma at end of 1^st sentence.

·      “fit” instead of “conducted”.

·      Suggest removing the phrase “between data” after “variable”.

 

Discussion

4.1

·      “TIM is associated with” instead of “TIM presents”

·      “Responses of the bird assemblages…” instead of “The responses of the assemblages…”

·      “, were more abundant under…” vs. “, showed higher abundances under…”

·      “application of inputs” – chemical inputs? Suggest being specific.

·      Suggest replacing “niches” with “habitat”

4.2

·      “…responses of bird abundance to CGM vs. EPM” instead of “…responses of bird abundance to grazing management practices”.

4.3

·      “, including the lack of ecological knowledge,” instead of “, including the lack of knowledge,”

4.4

·      “However, other details of management practices, such as stocking rates and duration of resting periods, are important to quantify for…” instead of “However, other details of management practices (stocking rates, duration of resting periods), may be relevant for…”

Comments on the Quality of English Language

I made minor suggestions to improve the English writing in my uploaded review document.

Author Response

Simple summary/Abstract

•     “negatively impacts” instead of “impacts negatively”

Response: Done

 

Introduction

•     “used in the Rio de la Plata Grasslands” instead of “involved”

Response: Done. We changed the sentence as follows: “The traditional cattle management in the Rio de la Plata Grasslands is based on extensive continuous grazing on natural grasslands (continuous grazing management, or CGM) and it is still practiced in many areas.”

 

•     “To address these issues,” – to address them for whom, or for what? Suggest making this sentence and the next sentence more specific. E.g., who developed the technologies, and who is using them?

Response: Done

 

•     “EPM aims” instead of “EPM aim”

Response: Done

 

•     “desired” grass species? Or all types of plants? And desired by whom – ranchers? Does “desired” mean native, or could non-native plant species be desired?

Response: Done, we  changed “desired species” by “cool-season grasses”

 

Materials and methods

2.1

•     “…and is highly interannually variable.” Instead of “present high interannual variability”

Response: Done

 

2.2

•     I’m not sure what is meant by “sample size for each grazing management”.

Response: Please note that we re-arranged the sentence for better understanding.

•     What are “appropriate” treatment comparisons – are they the ones that aligned with the treatments focused on in this study? Suggest being more specific.

Response: Done. We changed the sentence as follows: “When articles presented multiple treatment comparisons, we included all those that were aligned with the focus of our study, and considered these comparisons as nested in that study.”

 

2.3

•     Suggest removing comma at end of 1st sentence.

Response: Done

•     “fit” instead of “conducted”.

Response: Done

•     Suggest removing the phrase “between data” after “variable”.

Response: Done

 

Discussion

4.1

•     “TIM is associated with” instead of “TIM presents”

Response: Done

•     “Responses of the bird assemblages…” instead of “The responses of the assemblages…”

Response: Done

•     “, were more abundant under…” vs. “, showed higher abundances under…”

Response: Done

•     “application of inputs” – chemical inputs? Suggest being specific.

Response: Done

•     Suggest replacing “niches” with “habitat”

Response: Done

4.2

•     “…responses of bird abundance to CGM vs. EPM” instead of “…responses of bird abundance to grazing management practices”.

Response: Done

 

4.3

•     “, including the lack of ecological knowledge,” instead of “, including the lack of knowledge,”

Response: Done. We changed the sentence as follows: “However, different studies indicate the existence of several barriers to the adoption of ecological-knowledge based practices in the region, including the lack of knowledge by ranchers, which can be addressed by extension services, and lack of economic incentives for producers.”

 

4.4

•     “However, other details of management practices, such as stocking rates and duration of resting periods, are important to quantify for…” instead of “However, other details of management practices (stocking rates, duration of resting periods), may be relevant for…”

Response: Done

Reviewer 2 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

Authors have addressed all previous comments and questions

Author Response

Reviewer 2 left no comments on this version of the manuscript.

 

Reviewer 3 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

Since no co-ordinance are provided for the study sites, in Fig. 1 these sites should be numbered as in Table 1, 1A, and 1B.  

The main problem still persistes. It is about the bird abundance. No where, it is explained, how the abundance data (which are included in the original studies) have been extracted, and standarized/transformed/modified to be re-analysed in this paper (these data have to be standarized as based on different methodology, such as total counts, line transects, point count etc.). Furthermore, the data on the abundance (perhaps standarized in a scale from 1 to 5, where 1 is very rare, 2 is rare, 3 - uncommon, and so on) must be presented in Tab. 1A and 1B. Now we see, in the tables only data whether a species was 'present' or 'absent' in a given study plot.  That's not enough. This is not well documented, and it is crucial to understand the meta-analysis.   

Author Response

Since no co-ordinance are provided for the study sites, in Fig. 1 these sites should be numbered as in Table 1, 1A, and 1B.  

Response: Done. Please see Fig. 1.

 

The main problem still persistes. It is about the bird abundance. No where, it is explained, how the abundance data (which are included in the original studies) have been extracted, and standarized/transformed/modified to be re-analysed in this paper (these data have to be standarized as based on different methodology, such as total counts, line transects, point count etc.). Furthermore, the data on the abundance (perhaps standarized in a scale from 1 to 5, where 1 is very rare, 2 is rare, 3 - uncommon, and so on) must be presented in Tab. 1A and 1B. Now we see, in the tables only data whether a species was 'present' or 'absent' in a given study plot.  That's not enough. This is not well documented, and it is crucial to understand the meta-analysis.  

Response: Please notice that the bird abundance for each study was extracted as follows (lines 174-177): “For each case study described, we extracted, for each grazing management, mean and variance for bird richness and abundance, as well as sample size. Additionally, when the bird species list was provided, we calculated the abundance and richness of SESA grasslands birds (total bird count, restricted to SESA grasslands bird species)”.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study used a meta-analysis to compare bird abundance and richness between 3 grazing management approaches – technological inputs management (TIM), continuous grazing management (CGM), and ecosystem process management (EPM) – in the Rio de la Plata Grasslands, a temperate grassland ecosystem in South America. The need for the information presented in this study is well articulated and the study contributes valuable information about associations between grassland management and grassland bird diversity in the Neotropics. Overall, I think the amount of detail provided and the precision of language in the manuscript could be improved to improve the readers’ ability to understand the value of and the analysis approach used in the study. I detail major comments related to this below, as well as minor comments by line number.

 

Major comments

·       Increasing the amount of detail provided and precision of language. I tracked in the Minor comments section below where I thought detail could be added or the precision of language could be improved.

·       Clarifying the Data analysis section. I suggest adding information to and clarifying text in the Data analysis section to improve the reader’s ability to understand the analysis process used in this study. In this section, it’s stated that effect sizes are calculated using Hedge’s d, but also that random effects linear models are used but some of those models include fixed effects, which then would make the models not just random effects models. Hedge’s d is a comparison of two groups while linear models are a regression approach, so it needs to be clarified which approach was used and how. In addition, it would be helpful to explicitly state what the response variables are, and the covariates/fixed effects of interest. Finally, either in this section or previously in the Methods, it would be helpful to be explicit about the scale of the data – i.e., is there one row of data for each study? Or two rows of data if the study included 2 grazing management practices?

·       Examining species richness by grazing management for SESA species instead of all species. It isn’t clear why species richness for all species instead of just SESA species was one of the response variables in this study. Since species richness doesn’t include information about identity, it seems like it would be more valuable from a management perspective to know whether the grazing management practices explored in this study bolster (or not) species richness of grassland specialists specifically versus all bird species. The point that overall species richness ignores identity is indirectly discussed in the paragraph on line 33 in the Discussion. I think this study could provide a stronger contribution to the literature by using species richness of SESA species instead of overall species richness as the response variable for that metric.

·       Expanding upon nuance in grazing management effects on grassland birds, and relevance to the focal grassland system. I think an important aspect of grazing management effects on grassland birds that currently is missing in the manuscript is how details about the grazing management utilized are crucial for interpreting or predicting effects on bird species. For instance, “rotational grazing” can encompass a whole range of management practices, and thus that management practice will not uniformly influence grassland birds. Relatedly, stocking rate is an important metric for describing grazing management, and teasing apart impacts of cattle movement from those of stocking rate is necessary to tailor grazing management to support grassland bird populations. Yet, many studies examining grazing effects on grassland bird populations confound the two, and it’s not clear whether that issue may be the case in the papers used in this study. In addition, there isn’t much discussion of what the findings for this study mean for advancing grassland bird conservation in the focal grassland system – for example, are there management agencies in the relevant countries that could modify their practices? Or are the grasslands primarily on private lands, so improving grazing management to support grassland birds in the region would require more outreach and collaboration with landowners (and admittedly this would be additionally challenging to do across national boundaries)? I think the Discussion would be strengthened by having a paragraph focused on these topics, tailored to the grazing management practices utilized and conservation context in the Rio de la Plata Grasslands.

·       Adding literature and fixing the literature numbers. I suggest bolstering the amount of literature cited in the Introduction and Discussion, including adding citations of more recent research on grassland bird responses to grazing management (e.g., after 2016). For some of the main points of the paper, there are multiple studies that could be cited to support it, but only one paper is cited – e.g., in the Introduction, the sentence on line 51 about continuous grazing leading to overgrazing; in the Discussion, the sentence on line 302 referencing how TIM homogenizes vegetation structure and leads to the loss of niches. Including additional and more recent literature would strengthen the points being made by the authors while better acknowledging previous contributions to the literature from other scientists. In addition, it seems like the numbers of the literature cited in text are one off from what they should be – i.e., reference [35] in the main text should be reference [36].

 

Minor comments

44 – I’m not understanding the difference between “preserved” and “protected” in this sentence – suggest clarifying.

46 – what “impacts” are being referenced here? In this paragraph, suggest being more specific with the timeline. E.g., when were different technologies introduced (doesn’t have to be a specific year, but the general time period).

65 – “due to traditional continuous grazing” and TIM as well? Or just the former?

68 – Suggest changing “processes” to “process”. Same comment for line 179.

69 – I’m not sure what “controlled management” is; I suggest defining it here.

72 – I suggest weakening the language here, since we can’t prove a hypothesis, only find evidence to support it.

74 – “increases spatial and temporal heterogeneity” of what? Suggest being specific here.

82 – Suggest being more specific about which grassland bird species have experienced population declines – e.g., is it a particular group, like shortgrass species? Or grassland specialist species?

90 – It’s not clear to me why herbicides would benefit generalist species. In this sentence, does “generalist” mean grassland generalists, or species that are true generalists (can use many environments)? Suggest being more explicit.

92 – How does process-based management promote heterogeneity? Suggest being more specific here.

98 – Suggest “…richness or abundance…” instead of “…richness, abundance…”.

100 – Suggest adding to this sentence that the authors used a meta-analysis to study responses.

111, Study area – I suggest adding more information to this section to improve the reader’s ability to understand the focal ecological system. First, I think more detail is needed about dominant vegetation types and the ecological units. What are dominant vegetation types or species in the different ecological sites? In other words, how do the ecological units differ? Perhaps they could be described more generally by an ecological gradient. Relatedly, no information is provided about specific climate conditions in the area, which is important information for describing grassland ecosystems (e.g., average range of temperature and precipitation, seasonality of precipitation).

144 – Suggest using different colors for the diamonds as red/green isn’t distinguishable for some people with colorblindness.

164 – Suggest removing the “homogenous” qualifier; I don’t think it adds much information and it isn’t used to reference the species groups in the Discussion.

172 – Suggest adding to this sentence that the values were extracted for each grazing management type within studies (i.e., there’s not just one line of data per study), just so that’s clear.

174 – I’m not sure of the meaning of this sentence.

187 – I’m not sure what is meant by “while considering lack of independence in the data”.

188 – It isn’t clear to me exactly what information was being extracted from the studies. I suggest making that explicit in this paragraph.

196 – Suggest being specific about for what an effect size is being calculated for.

199 – Suggest rewriting this sentence so that the response variables are not within parentheticals, and are noted as response variables.

202 – I’m not sure what “whenever possible” means here, given the description in the Results that grass height only was included as a fixed effect in the model comparing EPM and CGM.

203 – Suggest being specific about what “inputs” are in this sentence.

208 – Suggest referring to the test as “Hedge’s q”.

215 – I think Table A1 should be in the main text, as the papers identified in the literature search are foundational to the meta-analysis. I also suggest adding to it a column that denotes which response variables were extracted from which studies. In addition, in Table A1, I’m counting 18 studies that were included in the descriptive analysis.

220 – In Table A1, I’m counting 14 studies that were included in the meta-analysis. I’m also not understanding how the math adds up re: line 221 – if 2 studies were excluded and 13 were included, that totals 15, not 17.

221 – I’m assuming “variable” here means response variable? I suggest being specific.

222 – I think it would be good to add a paragraph here (e.g., header could be Focal grazing management practices) that thoroughly describes the grazing management practices used in studies included in the meta-analysis. For example, what are the specific “inputs” that were used in the TIM studies? What specific management practices fell under the category of “ecological process management”, and how were those applied – e.g., describing how “rotational grazing” was applied: was it year-round or only during the growing season; was a single herd used, or multiple herds; etc. What were the stocking rates used in CGM and EPM studies? Knowing more details about the grazing management practices included in the analysis would improve the inference that could be made from this work.

226 – is it standard error or confidence intervals that are normally reported in text for a Hedge’s d test?

250 – I’m not sure what the “Q moderator test” is that’s mentioned here. Suggest adding information about this test to the Methods.

272 – Suggest adding “studies would be needed.” after “168”.

290 – Suggest replacing “present” with “face”

284 – could add here direct effects of insecticides on birds (e.g., poisoning).

311 – Have those species not been detected in TIM areas? Would be good to be explicit.

311 – 312 – grassland generalists had higher abundances in which type of grazing management? And since this sentence is focused on abundance, and not richness, perhaps it would fit better in the previous paragraph?  

322 – I think this paragraph could be strengthened with some additional interpretation. Why isn’t EPM supporting both short and tall grass species? It is a situation where there are inherent tradeoffs to supporting short vs. tall grass species, or is it that the ways EPM has been implemented need to be modified to support both groups? I’d guess the latter, which connects to my major comment above about including a paragraph in the Discussion speaking to the difference grazing management practices.

428 – “we” instead of “me”

Supplementary material Tables S1 and S2 – Suggest adding to the table captions what information is being noted by the stars, as that isn’t clear currently.

Comments for author File: Comments.docx

Comments on the Quality of English Language

I think the overall quality of the English is good, and that the clarity of the manuscript would benefit from editing by someone for whom English is their first language.

Author Response

REVIEWER #1 (in black notes)

 

This study used a meta-analysis to compare bird abundance and richness between 3 grazing management approaches – technological inputs management (TIM), continuous grazing management (CGM), and ecosystem process management (EPM) – in the Rio de la Plata Grasslands, a temperate grassland ecosystem in South America. The need for the information presented in this study is well articulated and the study contributes valuable information about associations between grassland management and grassland bird diversity in the Neotropics. Overall, I think the amount of detail provided and the precision of language in the manuscript could be improved to improve the readers’ ability to understand the value of and the analysis approach used in the study. I detail major comments related to this below, as well as minor comments by line number.

Major comments

Increasing the amount of detail provided and precision of language. I tracked in the Minor comments section below where I thought detail could be added or the precision of language could be improved.

Clarifying the Data analysis section. I suggest adding information to and clarifying text in the Data analysis section to improve the reader’s ability to understand the analysis process used in this study. In this section, it’s stated that effect sizes are calculated using Hedge’s d, but also that random effects linear models are used but some of those models include fixed effects, which then would make the models not just random effects models. Hedge’s d is a comparison of two groups while linear models are a regression approach, so it needs to be clarified which approach was used and how. In addition, it would be helpful to explicitly state what the response variables are, and the covariates/fixed effects of interest. Finally, either in this section or previously in the Methods, it would be helpful to be explicit about the scale of the data – i.e., is there one row of data for each study? Or two rows of data if the study included 2 grazing management practices?

Response: We agree with these comments and we re-arranged and improved the methodology section accordingly to improve the reader’s ability to understand the analysis.

 

First, we moved the sentence “Then, for each study case, we evaluated the effect size (difference in the response variable means between two management practices) by calculating the Hedges’d unbiased standardised mean difference [40], using the escalc function of the metafor package [41] in R [38].” to the Literature search and data extraction section, since the effect size (mean difference between treatments) is the input of our models.

 

Then, we improved the Data analysis by adding more details about the models we used.

“We included total bird richness and abundance and SESA grasslands bird abundance as response variables, (lack of studies prevented us to include SESA grasslands bird richness as a response variable). For each studied response variable we conducted a random effects multilevel linear model, which includes fixed (moderator) and random effects. This model assumes that studies have their own effect size and that they are selected randomly from a population of studies [42, 43, 44]. The models were fitted using restricted maximum likelihood (REML) by means of the rma.mv function of the metafor package [41] in R program [38]. When enough studies were available, we included grass height as a moderator (fixed effect) and we tested the influence of this moderator using the Test of Moderators of metafor package [41]. To account for the hierarchical dependence, we included the study ID as a random variable between data, since more than one study came from the same article [36, 42]. We considered effect size as small (0.2), moderate (0.5) and large (0.8) [45]. Due to the small sample sizes that result in low power in the tests, and the cost in this kind of research of type 2 errors, we used an alpha level of 0.1 to interpret results [46, 47].”

 

We relocated one sentence (now on line 212) since this corresponds to the interpretation of the mean effect sizes (meta-analysis output) and not to the input. We used a random effects model since  it is more realistic than a fixed effects one, which assumes that the true effect size is the same in all studies (Borenstein et al. 2009).

 

• Borenstein, M.; Hedges, L. V.; Higgins, J. P. T.; Rothstein, H. R. Introduction to Meta-analysis; Wiley: Chichester, UK, 2009

 

Examining species richness by grazing management for SESA species instead of all species.It  isn’t clear why species richness for all species instead of just SESA species was one of the response variables in this study. Since species richness doesn’t include information about identity, it seems like it would be more valuable from a management perspective to know whether the grazing management practices explored in this study bolster (or not) species richness of grassland specialists specifically versus all bird species. The point that overall species richness ignores identity is indirectly discussed in the paragraph on line 33 in the Discussion. I think this study could provide a stronger contribution to the literature by using species richness of SESA species instead of overall species richness as the response variable for that metric.

Response: We agree that analysing the response to just SESA species richness would have been more suitable. However, just one of the studies that were finally included in the meta-analysis reported SESA grasslands birds richness, so it was not possible to do this analysis. In this regard, we specified it on line 201: “We included total bird richness and abundance and SESA grasslands bird abundance as response variables, (lack of studies prevented us to include SESA grasslands bird richness as a response variable).”

We discussed the limits of our work in this regard in the section Study limits “We found only two studies that reported data about SESA grasslands bird richness [28, 58], so we could not analyse this variable, which could have provided more valuable insights.”

Expanding upon nuance in grazing management effects on grassland birds, and relevance to the focal grassland system. I think an important aspect of grazing management effects on grassland birds that currently is missing in the manuscript is how details about the grazing management utilized are crucial for interpreting or predicting effects on bird species. For instance, “rotational grazing” can encompass a whole range of management practices, and thus that management practice will not uniformly influence grassland birds. Relatedly, stocking rate is an important metric for describing grazing management, and teasing apart impacts of cattle movement from those of stocking rate is necessary to tailor grazing management to support grassland bird populations. Yet, many studies examining grazing effects on grassland bird populations confound the two, and it’s not clear whether that issue may be the case in the papers used in this study. In addition, there isn’t much discussion of what the findings for this study mean for advancing grassland bird conservation in the focal grassland system – for example, are there management agencies in the relevant countries that could modify their practices? Or are the grasslands primarily on private lands, so improving grazing management to support grassland birds in the region would require more outreach and collaboration with landowners (and admittedly this would be additionally challenging to do across national boundaries)? I think the Discussion would be strengthened by having a paragraph focused on these topics, tailored to the grazing management practices utilized and conservation context in the Rio de la Plata Grasslands.

Response: We agree on the importance of some details about grazing management for interpreting or predicting bird responses. To address these comments, we discussed the limitations of gathering many different practices in EPM category in the Study limits section. However, a more detailed analysis was not possible due to the small number of studies in the region. In regard to advancing grassland bird conservation in the focal grassland system, we added a Conservation implications section to discuss some barriers present in the region.

Adding literature and fixing the literature numbers. I suggest bolstering the amount of literature cited in the Introduction and Discussion, including adding citations of more recent research on grassland bird responses to grazing management (e.g., after 2016). For some of the main points of the paper, there are multiple studies that could be cited to support it, but only one paper is cited – e.g., in the Introduction, the sentence on line 51 about continuous grazing leading to overgrazing; in the Discussion, the sentence on line 302 referencing how TIM homogenizes vegetation structure and leads to the loss of niches. Including additional and more recent literature would strengthen the points being made by the authors while better acknowledging previous contributions to the literature from other scientists. In addition, it seems like the numbers of the literature cited in text are one off from what they should be – i.e., reference [35] in the main text should be reference [36].

Response: Please note that we increased the amount of literature cited in the Introduction and Discussion sections, and we added more recent research. In the Introduction section as well: lines 52 and 57 (Deregibus et al. 1995), on lines 55, 70, 73 (Jacobo et al 2024), on lines 63, 68 and 70 (Asad et al. 2024). In the Discussion: on line 382 (Gonzalez Fischer and Bilenca 2020, Némoz et al. 2013), on line 330 (Benton et al. 2003, Tews et al. 2004),on line 385 (Jacobo et al. 2024). Please note that we fixed the literature numbers.

• Asad, J.; Van Sundert, K.; Qüesta, A. V. E.; Preliasco, P.; De Paepe, J. L. Late Summer Intensive Grazing, an Alternative to Herbicide Application in Rangelands of the Flooding Pampa. Range Eco & Man 2024. DOI: 1016/j.rama.2024.06.010
• Benton, T. G.; Vickery, J. A.; Wilson, J. D. Farmland biodiversity: is habitat heterogeneity the key? Tr Eco & Evo 2003 18: 182-188.
• Deregibus, V. A.; Jacobo, E.; Rodríguez, A. Perspective: Improvement in rangeland condition of the Flooding Pampa of Argentina through controlled grazing. Afr J Range & Forage Sci 1995, 12: 92-96. DOI: 1080/10220119.1995.9647873
• González-Fischer, C.; Bilenca, D. Can we produce more beef without increasing its environmental impact? Argentina as a case study. Persp Eco Cons 2020 18: 1-11. DOI: 1016/j.pecon.2019.12.002
• Jacobo, E.; Rodríguez, A. Ecosystem Services of Grazed Grasslands and in the Flooding Pampa. Phyton-Int J Exp Botany 2024 93: 1179-1202. DOI: 32604/phyton.2024.050928
• Jacobo, E.J.; Martínez Ortiz, U.J.; Cotroneo, S.M.; Rodríguez, A.M. Adaptive Grazing of Native Grasslands Provides Ecosystem Services and Reduces Economic Instability for Livestock Systems in the Flooding Pampa, Argentina. Sustainability 2024 16: 4229. DOI: 3390/su16104229
• Némoz, J.P.; Giancola, S.I.; Bruno, M.S.; de la Vega, M.B.; Calvo, S.; Di Giano, S.; Rabaglio, M.D. Causas Que Afectan La Adopción De Tecnología En La Ganadería Bovina Para Carne En La Cuenca Del Salado, Provincia De BuenosAires: Enfoque Cualitativo. Estudios Socioeconómicos De La Adopción DeTecnología no. 5. Ediciones INTA: Buenos Aires, Argentina, 2013.
• Tews, J.; Brose, U.; Grimm, V.; Tielbörger, K.; Wichmann, M. C.; Schwager, M.; Jeltsch, F. Animal species diversity driven by habitat heterogeneity/diversity: the importance of keystone structures. J Biogeo 2004, 31: 79-92.

 

Minor comments

44 – I’m not understanding the difference between “preserved” and “protected” in this sentence – suggest clarifying.

Response: Please note that we re-arranged the sentence as follows to clarify: “Nowadays, ~40% of the region remains as natural or semi-natural grasslands, mostly used for cattle ranching. Only 1% of the region is covered by protected areas [2,7].” (line 46).

46 – what “impacts” are being referenced here? In this paragraph, suggest being more specific with the timeline. E.g., when were different technologies introduced (doesn’t have to be a specific year, but the general time period).

Response: Please note that we added on line 45 “During the 20th and 21st centuries” to specify when technologies were introduced. In response to reviewer 2, we re-arranged the beginning of the paragraph and the word “impacts” was deleted. Please see the answer to comment on line 45 to reviewer 2.

65 – “due to traditional continuous grazing” and TIM as well? Or just the former?

Response: We added “and TIM” because it is due to both practices.

68 – Suggest changing “processes” to “process”. Same comment for line 179.

Response: Done

69 – I’m not sure what “controlled management” is; I suggest defining it here.

Response: Please see that we substituted “controlled management” by “controlled grazing” and we added a definition: “rotational and controlled grazing, which involves the creation of paddocks with similar plant communities and the application of disturbances (instantaneous stocking rates) followed by resting periods” (line 68).

72 – I suggest weakening the language here, since we can’t prove a hypothesis, only find evidence to support it.

Response: Please note that we weakened the language here “Evidence shows that” (line 71).

74 – “increases spatial and temporal heterogeneity” of what? Suggest being specific here.

Response: Please see that we added “of vegetation structure” to clarify (line 72).

82 – Suggest being more specific about which grassland bird species have experienced population declines – e.g., is it a particular group, like shortgrass species? Or grassland specialist species?

Response: Please note that we added some examples of bird species that experienced population declines (lines 81-82): “such as the saffron-cowled blackbird (Xanthopsar flavus) and the bay-capped wren-spinetail (Spartonoica maluroides)”. It is not only a particular group which is affected but grassland birds of the three groups.

90 – It’s not clear to me why herbicides would benefit generalist species. In this sentence, does “generalist” mean grassland generalists, or species that are true generalists (can use many environments)? Suggest being more explicit.

Response: Please note that, to clarify, we changed the term “grassland generalists” for “broad species” (line 78), because this species use both short and tall grasslands. We added on line 89 “(non-SESA birds)”, to clarify that in that sentence by “generalists” we mean non-grasslands species. We corrected the terminology all through the text.

92 – How does process-based management promote heterogeneity? Suggest being more specific here.

Response: Please note that we added “the delineation of areas with similar plant communities in EPM ” (line 91) to specify how EPM promotes heterogeneity.

98 – Suggest “…richness or abundance…” instead of “…richness, abundance…”.

Response: Done

100 – Suggest adding to this sentence that the authors used a meta-analysis to study responses.

Response: Done

111, Study area – I suggest adding more information to this section to improve the reader’s ability to understand the focal ecological system. First, I think more detail is needed about dominant vegetation types and the ecological units. What are dominant vegetation types or species in the different ecological sites? In other words, how do the ecological units differ? Perhaps they could be described more generally by an ecological gradient. Relatedly, no information is provided about specific climate conditions in the area, which is important information for describing grassland ecosystems (e.g., average range of temperature and precipitation, seasonality of precipitation).

Response: In this regard, we added more information to this section. We added information about climate and ecological gradient through the region: “The region has moderate mean temperatures ranging from 14° in the South to 18° in the North [3]. Rainfall also varies from 500 mm in the South-west to 1600 mm in the North-east and present high interannual variability” and about dominant vegetation species in the different ecological sites: “In the Southern half of the region (Pampas), graminoid steppes and prairies were the original dominant vegetation (Nassella, Piptochaetium, Aristida, Melica, Briza, Bromus, Eragrostis and Poa), while in Southern and Northern Campos, the dominant grass species belong to the genera Paspalum, Andropogon and Axonopus”.

144 – Suggest using different colors for the diamonds as red/green isn’t distinguishable for some people with colorblindness.

Response: Done

164 – Suggest removing the “homogenous” qualifier; I don’t think it adds much information and it isn’t used to reference the species groups in the Discussion.

Response: Done

172 – Suggest adding to this sentence that the values were extracted for each grazing management type within studies (i.e., there’s not just one line of data per study), just so that’s clear.

Response: Done

174 – I’m not sure of the meaning of this sentence.

Response: Please note that we eliminated this sentence and clarified what we meant to say further in the text, on line 201. We excluded from the analysis those variables that were found in less than three studies (SESA grasslands birds richness).

187 – I’m not sure what is meant by “while considering lack of independence in the data”.

Response: Please note that we substituted this phrase by “and we considered these comparisons were nested in the study” (line 185) to clarify.

188 – It isn’t clear to me exactly what information was being extracted from the studies. I suggest making that explicit in this paragraph.

Response: Please see that we added some information previously to clarify what information was extracted from the studies on line 173: “For each case study described, we extracted mean and variance for bird richness and abundance, as well as sample size for each grazing management.”

196 – Suggest being specific about for what an effect size is being calculated for.

Response: Please note that we added some information about the calculation of effect sizes “We evaluated the effect size (difference in the response variable means between two management practices)” (194). This effect size constitutes the input of the meta-analysis model.

199 – Suggest rewriting this sentence so that the response variables are not within parentheticals, and are noted as response variables.

Response: Done

202 – I’m not sure what “whenever possible” means here, given the description in the Results that grass height only was included as a fixed effect in the model comparing EPM and CGM.

Response: Please note that we changed “Whenever possible” for “When enough studies were present” (line 208). In the model comparing TIM and CGM the amount of studies did not allow us to include a moderator without losing power.

203 – Suggest being specific about what “inputs” are in this sentence.

Response: Please see major comment about Data Analysis.

208 – Suggest referring to the test as “Hedge’s q”.

Response: We prefer to stick to the usual denomination in literature: “Q statistic” (see Barzan et al. 2020, Lima et al 2018). We did not find this test referred to as “Hedge’s q”.

• Barzan, F. R.; Bellis, L. M.; Dardanelli, S. Livestock grazing constrains bird abundance and species richness: A global meta-analysis. Basic & Appl Eco 2021, 56: 289-298. DOI: 10.1016/j.baae.2021.02.002
• Lima, F.; Hannibal, W.; Cunha, R.; Oliveira-Santos, L. G. R.; Fernandez, F. A. S. Conservación de pastizales y sabanas: Un meta-análisis sobre las respuestas de los mamíferos a las perturbaciones antropogénicas. Biodiversity and Conservation 2018, 27, 385–402. DOI: 10.1007/s10531-017-1434-6.

 

215 – I think Table A1 should be in the main text, as the papers identified in the literature search are foundational to the meta-analysis. I also suggest adding to it a column that denotes which response variables were extracted from which studies. In addition, in Table A1, I’m counting 18 studies that were included in the descriptive analysis.

Response: Please see that we moved Table A1 to the main text and we added a column with the response variables extracted from each article. We clarified in the text on line 223 why the table includes 18 study cases: “We obtained 18 study cases belonging to 17 articles (Table 1; one study [50] included two study cases that were independent since they correspond to different  ecological conditions).”

220 – In Table A1, I’m counting 14 studies that were included in the meta-analysis. I’m also not understanding how the math adds up re: line 221 – if 2 studies were excluded and 13 were included, that totals 15, not 17.

Response: Please note that we clarified there were 14 study cases (from 13 articles) on line 232: “Fourteen of the 18 selected study cases”. We also added the exclusion criteria for the two other articles: “two articles [51, 52] were excluded since they only studied the abundances of a few species instead of all the assemblage, whereas other two studies were excluded due to insufficient data”

221 – I’m assuming “variable” here means response variable? I suggest being specific.

Response: Done

222 – I think it would be good to add a paragraph here (e.g., header could be Focal grazing management practices) that thoroughly describes the grazing management practices used in studies included in the meta-analysis. For example, what are the specific “inputs” that were used in the TIM studies? What specific management practices fell under the category of “ecological process management”, and how were those applied – e.g., describing how “rotational grazing” was applied: was it year-round or only during the growing season; was a single herd used, or multiple herds; etc. What were the stocking rates used in CGM and EPM studies? Knowing more details about the grazing management practices included in the analysis would improve the inference that could be made from this work.

Response: Please note that we provided more details about grazing management practices in the Literature search and data extraction section on lines 178-181.

226 – is it standard error or confidence intervals that are normally reported in text for a Hedge’s d test?

Response: Please note that we eliminated the mean effect size and the standard error from the text following Reviewer 2’ comment about avoiding repeated information. The information of mean effect size and confidence interval (which is the most normally reported information) is already provided in the figures.

250 – I’m not sure what the “Q moderator test” is that’s mentioned here. Suggest adding information about this test to the Methods.

Response: Please note that we added in the Methods the phrase “and we tested the influence of this moderator using the Test of Moderators of metafor package [41]” to explain the test we used and we referred to it as “Test of Moderators” through the rest of the text.

272 – Suggest adding “studies would be needed.” after “168”.

Response: Done

290 – Suggest replacing “present” with “face”

Response: Done

284 – could add here direct effects of insecticides on birds (e.g., poisoning).

Response: Although previous literature refers to cases of direct poisoning of birds, none of the included articles refers to it directly.

311 – Have those species not been detected in TIM areas? Would be good to be explicit.

Response: Done

311 – 312 – grassland generalists had higher abundances in which type of grazing management? And since this sentence is focused on abundance, and not richness, perhaps it would fit better in the previous paragraph? 

Response: Please see that we clarified the grazing management and relocated the sentence as suggested.

322 – I think this paragraph could be strengthened with some additional interpretation. Why isn’t EPM supporting both short and tall grass species? It is a situation where there are inherent tradeoffs to supporting short vs. tall grass species, or is it that the ways EPM has been implemented need to be modified to support both groups? I’d guess the latter, which connects to my major comment above about including a paragraph in the Discussion speaking to the difference grazing management practices.

Response: We think there is an inherent tradeoff in this case. While in short grasslands, independently of the grazing management, tall grass species will not be supported, in tall grasslands EPM may support both short and tall grass species, but the abundances (which is the focus of this paragraph) will be compromised.

428 – “we” instead of “me”

Response: Done

Supplementary material Tables S1 and S2 – Suggest adding to the table captions what information is being noted by the stars, as that isn’t clear currently.

Response: Done

Reviewer 2 Report

Comments and Suggestions for Authors

Comments and suggested edits attached

Comments for author File: Comments.docx

Comments on the Quality of English Language

I don't think there is a translation issue here. I do feel, however, that the writing could be greatly improved. 

Author Response

REVIEWER #2 (in black notes)

 

10- “bird populations are known to be affected by livestock grazing practices.” instead of “ how grazing is managed affects bird populations.”

Response: Done

 

12- “abundance” instead of “abundances”
            Response: Done

 

12- Eliminate“to two other methods”

Response: Done

 

12- I was trying to reword this sentence to read better but I can’t really understand what’s being conveyed here

Response: Please note that we re-arranged these sentences following the abstract for better understanding.

 

15- eliminate “on”

Response: Done

 

16- “because” You can’t claim causation here. Only correlation

Response: Please note that we substituted “because” with “which can be attributed to the fact that”

 

16- “The effect of EPM” instead of “EPM’s effect”

Response: Done

 

16- “is dependent” instead of “depends”

Response: Done

 

19- CGM isn’t mentioned in the summary. If the other two are mentioned, so should CGM

Response: We added “compared to CGM” on lines 16 and 18.

 

21- The abstract is much better written and organized than the short summary. I would redo the short summary with select sentences from the abstract.

Response: Please note that we re-arranged many sentences of the short summary for better understanding.

 

22- “bird populations are known to be affected by livestock grazing practices. This can” instead of  “are affected by grazing management practices which may”

Response: Done

 

25- eliminate “creating”

Response: Done

 

28- So are the comparisons only CGM/TIM and CGM/EPM? If all three are being compared to each other, this should probably read: “We compared species richness and abundance on ranches under continuous grazing management (control, CGM), technological inputs management (TIM, herbicides and exotic pastures), and ranches under ecological process-based management (EPM).”

Response: Please note that we compared only CGM/TIM and CGM/EPM, not all three to each other. See the response to comment on line 265 below.

 

31- Eliminate “We extracted the effect sizes (Hedge’s d) and conducted random effects linear models.” No need to detail methods here. Add “We used mixed linear models to investigate grazing regime impacts.”

Response: Done. We added “random effects multilevel linear models” instead of “mixed linear models”, please see response to Reviewer 1’s major comment about Data analysis.

 

31-”Our results indicate a” instead of “We found”

Response: Done

 

31-”depends on grassland height” This should something like: “appears to be dependent on” (not ideal) or “highly correlated with”

Response: Done

 

32- “decline in short grasses and increase in tallgrasses. Our meta-analysis suggests that EPM practices may be beneficial to the conservation of endangered tall-grass birds.” instead of “negative influence of EPM in short grasslands and the opposite trend in tall grasslands, which can be attributed to differences in avian composition (tall-grass specialists and generalists).  Our results show that EPM practices contribute to the conservation of endangered tall-grass birds.”

Response: Done

 

44- eliminate “about”

Response: We changed “about only” for “only about”.

 

44- “Currently, about only 40% of the region is preserved as grasslands and used for cattle farming; only 1 % of the area once covered by grasslands is protected”  I think the word ‘preserved’ is inappropriate here. The grasslands are being used and impacted by land use (livestock grazing). “protected” From all land use?

Response: Please see the response to Reviewer 1’s comment on line 44.

 

45- “The current land use practices in the Río de la Plata Grasslands are related to the European colonisation of the southern portion of the continent during the sixteenth century [5]. The use of prescribed fire and introduction of cattle caused drastic changes in the landscape [3].” instead of  “The current impacts on the Río de la Plata Grasslands are related to the European colonisation of the South of the continent during the sixteenth century [5], due to the use of fire and the introduction of cattle, that changed drastically the landscape of the region [3].”

Response: Done

 

49- “During the twentieth and twenty-first centuries, many grasslands were replaced by crop fields [7] while there are some areas where traditional farming activities remain, involving continuous grazing on natural grasslands [8].” I would switch this around: “While there are some areas where traditional farming activities (continuous grazing on natural grasslands) remain, many grasslands were replaced by crops during the twentieth and twenty-first centuries”

Response: Done

 

51- “native degraded grasslands”I thought these were natural grasslands? Not degraded? unclear

Response: Done

 

52- “with a lack of match between forage supply and stocking rates” This is strangely worded

Response: Please note that we re-arranged the sentence: “Continuous grazing without adjusting stocking rates to match forage supply”

 

55- I tried to help re order this but this is very confusing.

Response: Please see that we re-arranged the sentence as follows (lines 56-59):

“Following the adoption of these technologies, two new types of management have been developed [12, 9]. Technological input management (TIM) is based on the use of inputs such as herbicides, seeds, and fertilisers [12, 13, 14], whereas ecological process-based management (EPM) is based on ecological processes and grassland knowledge [10, 15]. ”

 

60- “Currently, grazing management practices that incorporate technological input management (TIM) to” instead of “Nowadays, grazing management practices that incorporate technological inputs to”

Response: Done

 

64- “CGM” instead of “continuous grazing”

Response: Done

 

67- Eliminate “from excessive degradation”

Response: Done

 

67- “To address this problem” instead of “In this regard”

Response: Done

 

67- Add “(EPM)”

Response: Done

 

67- “such as” instead of “including”

Response: Done

 

71- “demonstrated” instead of “proved”

Response: Please see that we re-arranged the sentence in response to Reviewer 1’s comment on line 72.

 

77- “22 of which are listed threatened or near threatened” instead “ which regularly use grasslands, with 22 of them threatened or near threatened”
            Response: Done

 

79- “Vegetation height is a highly influential factor for biodiversity and species composition of” instead of “The height of the vegetation is one of the main factors affecting biodiversity and species composition of “

Response: Done

 

84- “for grassland-dependent birds” instead of “and resulting in changes in bird distribution and abundance”

Response: Done

 

87- “CGM” instead of “continuous grazing”

Response: Done

 

89- Here’s another of the “on one hand” things. It reads very poorly and should be reworded

Response: Done

 

92- “EPM” instead of “process-based management”

Response: Done

 

93- This seems like a very odd thing to throw in at the end of the introduction. I’d probably just delete it

Response: Please note that we re-arranged the sentence because this idea is fundamental to explain our hypothesis, as follows (lines 93-95): “ In this regard, some studies indicate that management practices that promote spatial heterogeneity are associated with a more spatially diverse avian community [31, 32]. ”.

 

99- “CGM” instead of “continuous grazing”

Response: Done

 

100- “investigated” instead of “studied”

Response: Done

 

101-”changes in bird assemblage under” instead of “responses of the bird assemblage to”

Response: We prefer to keep this sentence as it was, just as the title of the article.

 

101- Eliminate “Firstly”

Response: Done

 

102- “CGM” instead of “traditional continuous grazing” and “to TIM” instead of “with grazing practices reliant on technological inputs”

Response: Done

 

104- “We also” instead of “Secondly, we”

Response: Done

 

105- “CGM” instead of “traditional continuous grazing” and “to EPM” instead of “with ecological processes-based management practices”

Response: Done

 

106- “EPM helps” instead of “that ecological processes-based management practices”

Response: Done

 

108- “CGM” instead of “continuous grazing”

Response: Done

 

115- Eliminate “at least”

Response: Done

 

115-”high” instead of “a great”

Response: Done

 

116-”floral grass composition” Floral grass?

Response: We eliminated the word “floral”

 

123- Eliminate “Currently”

Response: Done

 

124- Eliminate “located”

Response: Done

 

170- So I guess I’m very curious as to what constituted “not appropriate” for title and abstract and “full text did not match the criteria”. 13 articles down from 296 is a big jump

Response: Please see response to Editor’s comments. Although sample size is small, as Reviewer 3 points out, Neotropical grassland communities are not intensively-studied, so we consider it is acceptable.

 

175- “TIM” instead of “technological inputs management” (hereafter TIM)”

Response: Done

 

179- “EPM” instead of “ecological process-based management” (hereafter EPM)”

Response: Done

 

183- “CGM” instead of “continuous grazing management” (control, hereafter CGM)”

Response: Done

 

185- “When articles presented multiple treatment comparisons, we included all appropriate ones, while considering the lack of independence in the data [31].” I think authors should explain a bit more here. Lack of independence in the data

Response: Please see the response to Reviewer 1’s comment on line 187

 

200- “random effects model” Inappropriate model. See comment below

Response: Please see the response to Reviewer 1’s major comment about Data Analysis above.

 

203- “We included the study as a random effect to account for the lack of independence between data” Since no heterogeneity among effect sizes were found across articles, study should be a fixed effect. I’m not sure why grass height is a fixed effect. If anything the management practice should be fixed. Perhaps grass height could be included as a random effect but honestly I don’t think it belongs in either role.

Response: Please see the response to Reviewer 1’s major comment about Data Analysis above.

 

208- “Publication bias” Explain…

Response: Please note that we re-arranged this sentence to make it clearer “To determine whether effect size and error were correlated, we examined potential publication bias through funnel plots [48] and by calculating Kendall’s tau correlation to determine ”. Also, in the following sentence, about Rosenthal’s fail-safe number we provide an explanation of what publication bias implies.

 

220- This I’m not understanding, and maybe I missed it. Why 4 dropped?

Response: Please see the response to Reviewer 1’s comment about line 220.

 

228- “these studies found” instead of “we found”

Response: Please see that we changed “we found” for “there is”

 

238- Authors have already described these results in text. This figure is unnecessary

Response: Please see the response to Reviewer 1’s comment about line 226.

 

247- “Thus, to interpret the heterogeneity in effect sizes we included grassland height in the model as a moderator.” No. Since heterogeneity among studies is present, ‘study’ should be a random effect and grass height can be left alone. What it sounds like (below) is that the authors used grassland height to block the meta-analysis. So the analysis was blocked by grassland height since the influence of EPM is highly dependent on veg height

Response: Please note that we included grassland height as a moderator since, “the test of a moderator variable in a meta-analysis is akin to the test of an interaction in a primary study” (Borenstein et al. 2009). We considered that bird assemblage’s response to grazing management would depend on grassland height. To clarify how we extracted the information of grassland height, we added a sentence on line 197 as follows:

“We extracted data about grassland height as a possible moderator variable. We classified the studied grasslands as “tall” or “short/medium”, using grass species composition reported in the articles.”

• Borenstein, M.; Hedges, L. V.; Higgins, J. P. T.; Rothstein, H. R. Introduction to Meta-analysis; Wiley: Chichester, UK, 2009

 

260- Eliminate Figure 4

Response: Please see the response to Reviewer 1’s comment about line 226 above.

 

265- This is more of a fundamental question but I’m curious as to why there was not a 3 way comparison. TIM+CGM EPM+CGM and TIM+EPM.

Response: We agree it would have been more interesting to perform a 3 way comparison between the three practices. However, only two articles included the three treatments (one of which was not finally included in the meta-analysis), so it was not possible.

 

278- “In Neotropical temperate grasslands, TIM presents lower bird abundance compared to CGM, which is consistent with our hypothesis.” Should be in results, not discussion

Response: Please note that we kept this sentence given that, although it corresponds with the results, in this case summarizing the main idea of the results helps to better understand the discussion.

 

301- “In accordance with our hypothesis, TIM also presents lower bird richness compared to CGM.” Should be in results

Response: Please see response to comment on line 278 above.

 

322- “In Neotropical temperate grasslands, no differences in bird abundance were found between treatments,” This should be in results. Discussion can start from “even though..”

Response: Please see response to comment on line 278 above.

 

333- “We found no influence of EPM on bird richness compared to CGM. However, EPM may contribute to retain some grassland specialists in assemblage composition compared to CGM [58].” This should be in results; Discussion can start with “EPM favours..”

Response: Please see response to comment on line 278 above.

Reviewer 3 Report

Comments and Suggestions for Authors

This is a well-conducted meta-analysis regarding grassland birds under differetnt type of management. The sample size, as the authors acknowledge, is however small to make a firm statements regarding the hypothetised differences. This is, however, acceptable here as the Neotropical avian communities are not so intesively-studied, as for example forest avian communities in Europe. 

The main problem which emerges from this presentation is that birds are actually neglected in the presentation. The authors focus too much on statistics, ommiting the species. In ecology the real knowledge is based on the knowledge of species. Here, it is even hard to find the number of species investigated. I therefore suggest to include (for example as Table 2A in Appendix) a list of all bird species investigated, with data (mean, ranges, variance) on the abundance (at least in a scale: very rare, rare, uncommon, common, very common), and the frequency of occurence of each species in these 13 studied plots (e.g. 100%, 85% etc.). also for each species information should be given on its grass preference (e.g. short-grass specialist, generalist, etc.) and feeding guild (granivorous, insectivorous, frugivorous etc.). 

The selected plots (n=13) should be shown on the map with appropriate symbols for tall grass, short grass or mixed plots. For each plot (perhaps in the form of table) data regarding the plot size (in ha), studied years, number of species recorded, including grass specialists, and other indices if possible (Shannon, Simpson, Cummulative dominance, ....). in this way the statistical analysis will be put on the background which is necessary to better understand the meta-analysis.      

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Only minor editing required.  Examples are in pages 1-2

Author Response

This is a well-conducted meta-analysis regarding grassland birds under differetnt type of management. The sample size, as the authors acknowledge, is however small to make a firm statements regarding the hypothetised differences. This is, however, acceptable here as the Neotropical avian communities are not so intesively-studied, as for example forest avian communities in Europe.

The main problem which emerges from this presentation is that birds are actually neglected in the presentation. The authors focus too much on statistics, ommiting the species. In ecology the real knowledge is based on the knowledge of species. Here, it is even hard to find the number of species investigated. I therefore suggest to include (for example as Table 2A in Appendix) a list of all bird species investigated, with data (mean, ranges, variance) on the abundance (at least in a scale: very rare, rare, uncommon, common, very common), and the frequency of occurence of each species in these 13 studied plots (e.g. 100%, 85% etc.). also for each species information should be given on its grass preference (e.g. short-grass specialist, generalist, etc.) and feeding guild (granivorous, insectivorous, frugivorous etc.).

The selected plots (n=13) should be shown on the map with appropriate symbols for tall grass, short grass or mixed plots. For each plot (perhaps in the form of table) data regarding the plot size (in ha), studied years, number of species recorded, including grass specialists, and other indices if possible (Shannon, Simpson, Cummulative dominance, ....). in this way the statistical analysis will be put on the background which is necessary to better understand the meta-analysis.  

Response: Please note that we made changes all through the text in order to focus on bird species and ecological knowledge. We included examples of species with conservation issues in the introduction (line 81). In addition, we included the total number of bird species and the number of species of each of the groups of grassland use (lines 229-231). We also moved the tables from Supplementary Materials to Appendix B as suggested to focus on the bird species. We provide in these tables a list of the species present in each study and we specify to which group each species correspond (tall-grass SESA, short-grass SESA, broad SESA or non-SESA). When this information was not present in the articles, we asked the authors to provide it to us and in most of the cases it was possible to get it. We refer to the species list on several occasions in the Discussion. Please note that the map includes different symbols for tall and short/medium grass sites and that we changed the symbols following Reviewer 1’s comment on line 144. We agree it would have been interesting to include more information such as the suggested indices, but it was not possible since most of the studies did not report them.

 

38- “between 31% and 43%” It should be explained why the range is so big

             Response: Please note that this estimation comes from the cited article (Malloch-Brown et al. 2000).

• Malloch-Brown, M.M.; Töpfer, K.; Wolfensohn; J.D., Lash, J. World resources 2000-2001, people and ecosystems: the fraying web of life; World Resources Institute: Washington D.C., USA, 2000.

 

38- Add “of the world”

              Response: Done

 

43- “only about” instead of “about only”

              Response: Please see response to Reviewer 2’s comment on line 44.                    

 

45- “once covered” so it is protected, but no longer a grassland??

              Response: Please see the response to Reviewer 1’s comment on line 44.    

 

47- “southern part” instead of “South”

              Response: Please see the response to Reviewer 2’s comment on line 45.

 

References:

• Asad, J.; Van Sundert, K.; Qüesta, A. V. E.; Preliasco, P.; De Paepe, J. L. Late Summer Intensive Grazing, an Alternative to Herbicide Application in Rangelands of the Flooding Pampa. Range Eco & Man 2024. DOI: 1016/j.rama.2024.06.010
• Barzan, F. R.; Bellis, L. M.; Dardanelli, S. Livestock grazing constrains bird abundance and species richness: A global meta-analysis. Basic & Appl Eco 2021, 56: 289-298. DOI: 10.1016/j.baae.2021.02.002
• Benton, T. G.; Vickery, J. A.; Wilson, J. D. Farmland biodiversity: is habitat heterogeneity the key? Tr Eco & Evo 2003 18: 182-188.
• Borenstein, M.; Hedges, L. V.; Higgins, J. P. T.; Rothstein, H. R. Introduction to Meta-analysis; Wiley: Chichester, UK, 2009.
• Codesido, M.; Bilenca, D.N. Influencia de la intensidad de pastoreo sobre ensambles de aves en espartillares de la Bahía de Samborombón, Argentina. Hornero 2021, 36: 21-30. DOI: 56178/eh.v36i1.427
• Comparatore, V. M.; Martínez, M. M.; Vassallo, A. I.; Barg, M.; Isacch, J. P. Abundancia y relaciones con el hábitat de aves y mamíferos en pastizales de Paspalum quadrifarium (Paja Colorada) manejados con fuego (Prov. de Buenos Aires, Argentina). Interciencia Caracas 1996, 21: 228-237.
• Deregibus, V. A.; Jacobo, E.; Rodríguez, A. Perspective: Improvement in rangeland condition of the Flooding Pampa of Argentina through controlled grazing. Afr J Range & Forage Sci 1995, 12: 92-96. DOI: 1080/10220119.1995.9647873
• González-Fischer, C.; Bilenca, D. Can we produce more beef without increasing its environmental impact? Argentina as a case study. Persp Eco Cons 2020 18: 1-11. DOI: 1016/j.pecon.2019.12.002
• Jacobo, E.J.; Martínez Ortiz, U.J.; Cotroneo, S.M.; Rodríguez, A.M. Adaptive Grazing of Native Grasslands Provides Ecosystem Services and Reduces Economic Instability for Livestock Systems in the Flooding Pampa, Argentina. Sustainability 2024 16: 4229. DOI: 3390/su16104229
• Jacobo, E.; Rodríguez, A. Ecosystem Services of Grazed Grasslands and in the Flooding Pampa. Phyton-Int J Exp Botany 2024 93: 1179-1202. DOI: 32604/phyton.2024.050928
• Lima, F.; Hannibal, W.; Cunha, R.; Oliveira-Santos, L. G. R.; Fernandez, F. A. S. Conservación de pastizales y sabanas: Un meta-análisis sobre las respuestas de los mamíferos a las perturbaciones antropogénicas. Biodiversity and Conservation 2018, 27, 385–402. DOI: 10.1007/s10531-017-1434-6.
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