The Impact of Climate Change and Human Activities on the Habitat Distribution and Ecological Corridors of Hoolock tianxing in Western Yunnan Province, China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

General Comments:

This paper is important because it focuses on habitat suitability and geographic distribution of the Endangered (EN) Gaoligong (or, Skywalker) hoolock gibbon ('Hoolock tianxiang') under predicted environmental conditions for future climatic projections. So, thinking about this Endangered (or, potentially, Critically Endangered - CR) species under future climatic regimes and habitat conditions is important for advancing the conservation efforts for this species.

That said, there are several points through the paper where corrections to the text are recommended. Most of these remarks are minor and "editorial" in nature (e.g., correcting grammar). But, in a couple of cases, the theoretical context of the paper could have been better grounded -- the paper could be better "positioned" within the context of similar research at the interface of climate/environmental change and the viability of wildlife populations under future climatic regime conditions. These specific recommendations are presented below (by line number(s)).

Specific Comments:

Abstract, Line 19: "Gaoligong Hoolock Gibbons (Hoolock tianxing)" -- 'Gaoligong' is correctly capitalized because it is a regional place name.  However, "Hoolock Gibbons" are not proper names. The passage on line 19 should read, "Gaoligong hoolock gibbons (Hoolock tianxing)".

Abstract -- closing line (Line 38): To increase the impact to the 'Abstract', this closing phrase could be slightly reworded to read, "... the long-term survival of the Skywalker hoolock gibbons." Use of the widely recognized common name 'Skywalker gibbon' in the paper's Abstract would increase the profile and public recognition of this important report.

Introduction, Lines 59-60: "Understanding how climate change affects species distributions is essential for predicting future biodiversity trends and identifying priority conservation areas."  This statement could (or should) be linked to the key concept of latent extinction risk (see "Latent extinction risk and the future battlegrounds of mammal conservation" by Marcel Cardillo, Georgina M. Mace, John L. Gittleman, and Andy Purvis, (2006). PNAS 103 (11): 4157–4161. www.pnas.org; doi: 10.1073 pnas.0510541103). Linking the information in the submitted Geng et al. manuscript to the existing theory concerning future biodiversity conservation (e.g., Cardillo et al., 2006) would more firmly situate the submitted manuscript within the larger conservation biology context.

Introduction, Lines 70-71: "This knowledge is vital for creating adaptive management plans that support the long-term survival of species in a rapidly changing world." -- See my previous comment. There is certainly the larger theoretical framework of 'Latent Extinction Risk' within which to position this research report.

Introduction, Line 83: re. "Primates are highly sensitive to environmental changes, ...". This is a blanket statement that I think needs to be qualified. This is because not all primate species are, "... highly sensitive to environmental changes, ...". Although the Gaoligong hoolock gibbons are highly reliant on montane forest formations, there are numerous primate species that exhibit high behavioural and ecological flexibility and resilience to anthropogenic habitat change; some primate species even exhibit some degree of commensalism with human populations. The case of Hoolock tianxing relying on quite specific environmental conditions (reflecting a relatively narrow econiche) is not the "species profile" of many primate species that exhibit broader, more flexible econiches.

Introduction, Line 87: "... Gaoligong Hoolock Gibbon..." should be, "... Gaoligong hoolock gibbon...".

Introduction, Line 91: "... gibbons." should be "... Gaoligong hoolock gibbons." 

Introduction, Line 92: re. - "... Gaoligong Hoolock Gibbons, ..." -- "Hoolock" should be "hoolock", and "Gibbons" should be "gibbons". These same changes should also be made on Line 99 and Line 104.

 

Introduction, Line 111: re. - "... the gibbons..." -- More specific wording regarding the biological identity of the specific gibbon species is warranted here because there are multiple gibbon taxa that occur in China. Replace "... the gibbons..." with, "... for Gaoligong hoolock gibbons...". 

 

Introduction, Line 111: re. - "... China..." -- Revise to read, "... China's western Yunnan Province...".

 

Introduction, Line 113: re. - "... on their habitat suitability..." -- For clarity, replace "their" with "gibbon". 

 

Materials and Methods, Lines 131-132: re. - "The study area is rich in primate resources, hosting 12 species of primates, ...".

I suggest slight re-phrasing here, to read, "The study area is rich in primate taxa, hosting 12 species of primates, ...".

 

Materials and Methods, Line 140: Be specific here -- revise "... daily movement distance of primates... " to read, "... daily movement distance of Gaoligong hoolock gibbons...".

 

Materials and Methods, Lines 142-143: re. composition of "Figure 1" -- The dark blue dots indicating the sighting/presence of Hoolock tianxing are *very* difficult to see against the background (i.e., habitat) colours on this map. Bright pink dots would show up much more clearly.

 

Section 3.2 - Habitat distributions under different climatic scenarios: 

Lines 227-228: re., "... scenarios were shown in Figures 3a and 4, ..." -- "were" should be "are".

 

Section 3.3 - Altitudinal distribution of habitats across varying climatic scenarios:

Lines 259-262 -- re., "In contrast, mid-elevation areas (2396–2996m) gradually emerged as core habitats, with the proportion of suitability increasing markedly across all future scenarios. Similarly, Similarly, mid-high elevation areas...". A similar prediction of future "ecological retreat" by another high altitude primate species (i.e., the gelada (Theropithecus gelada), endemic to Ethiopia's Simien Mountains ) because of altitudinal shifts in vegetation and changing suitability in habitats could be cited here -- see: Dunbar, R.I.M. (1998). "Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach". Global Change Biology 4(3): 293-304.

 

Section 3.4 - Distribution of ecological corridors, Line 269 -- re., "... climatic scenario, the species’ ecological corridors...". The phrasing here is awkward. Use of the term " species' " could be read as a plural possessive, even though the authors are just referring to a single species. A slight re-wording to this phrase could clear up this problem: "... climatic scenario, ecological corridors available to the species were primarily...". 

 

Line 272 - See previous comment... the same applies here concerning use of the term " species' ". Alternative phrasing could be, "... scenarios, ecological corridors for the species showed...".

 

Section 4.1 - Impacts of climatic variables and habitat suitability patterns:

Lines 290-291 - re. the phrase "... essential for the species’ survival and reproduction." -- See the two previous comments. Rephrase the passage to read, "... essential for the survival and reproduction of the species."

 

Line 295-296 - re. the phrase, "... demonstrated the species’ acute sensitivity...". Rephrase this passage to read, "... demonstrated the acute sensitivity of H. tianxing...". 

 

Line 299 - re. source citation '[41]': Another relevant source citation that could be made here is:

Dunbar, R.I.M. (1998). Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach. Global Change Biology 4(3): 293-304.

This would mean the source originally cited here (i.e., [41] -- McCain, 2007) would become source [42].

 

Line 307 - Revise the phrase, "... climate change on the gibbons ..." to read, "... climate change on the Gaoligong gibbons...".

 

Line 307 - Following the insertion of the Dunbar (1998) source here, the source citation number here (i.e., [42]) should be changed to [43].

 

Section 4.2 - Habitat decline under future climate scenarios:

 

Line 310 -- re. - "... gibbons."; Revise to read, "... Gaoligong gibbons.".

 

Line 312 -- re. - "... threat posed by global warming to habitat availability..."; Revise to read, "... threat posed by global warming to Gaoligong gibbon habitat availability...".

 

Line 316 -- re. See previous comments concerning the problematic nature of using "species" in the possessive (i.e., species'). Rephrase the passage to read, "... highlighting the reliance of Gaoligong gibbons on cooler and more stable microclimates...". 

 

Line 327 -- re. the phrase, "... long-term survival of the gibbons...". Reword to read, "... long-term survival of the Gaoligong gibbons...".

 

Section 4.3 - Fragmentation and connectivity of ecological corridors:

 

Line 331 -- re. the phrase, "... for the gibbons...". Replace "the" with "Gaoligong" -- i.e., "... for Gaoligong gibbons...".

 

Line 340 -- re. use of the term "extinctions" -- The more precise term to use here would be "extirpations", rather than "extinctions".

 

Line 340 -- re. the closing phrase to the sentence: "... the species’ long-term survival." Reword this phrase to read: "... the long-term survival of the species."

 

Lines 353-354 -- Replace "... local extinctions..." with "... extirpations...".

 

Section 4.4 - Conservation strategies and cross-border collaboration:

 

Line 358 -- Revise "...the gibbons," to read "... the Gaoligong gibbons...".

 

Line 365 -- Instead of "observed", a better word to use here would be "predicted".

 

Lines 368-370 -- re., "The establishment of green corridors or stepping stones has been shown to enhance connectivity and mitigate the effects of habitat fragmentation on species persistence."  Backing this statement up with a source citation or two would be worthwhile.

 

Lines 371-372 -- re., "... the gibbon populations remain...". Rephrase this to read, "... the Gaoligong gibbon populations...".

 

Line 383 -- re., "... of the gibbons.". Revise to read, "... of the Gaoligong gibbons."

 

Conclusions, Line 386: re. "... the gibbons..." -- Revise this phrase to specify "... the Tianxiang hoolock gibbons...".

 

Conclusions, Lines 387-388: re. "... revealed that key climatic variables, including elevation, temperature range, seasonality, and precipitation, play a critical role...". The phrasing of this sentence includes a plural ("variables") to singular ("... a critical role...") tense shift that needs to be corrected. This sentence includes a tense shift -- you go from the plural voice (i.e., "... climatic variables..."), to speaking in the singular (i.e., ".. play a critical role..."). To  correct this, the wording of the entire sentence should also be in the plural voice (i.e., "... climatic variables... play critical roles...").

 

Conclusions, Line 391 -- re.: the phrase, "... scenario, where habitat area could decrease...". This phrase needs to be revised to be more precise. Replace "... where habitat area could decrease...", with, "... where suitable habitat areas could decrease...". 

 

Conclusions, Line 396 -- Replace "...local extinctions." with "... extirpations.".

 

Conclusions, Line 402 -- Replace "... gibbons." with "... Gaoligong hoolock gibbons."

 

References section -- There are several irregularities and stylistic errors in the list of "References" that need to be addressed/corrected. For example, all the journal names and book titles of the sources you identify in the list of 'References' should be italicized.

In addition, the following elements of the 'References' section of the manuscript need to be corrected or revised:

 

Line 422 -- In the journal title "Ecology letters", "Letters" should be capitalized.

 

Line 429 -- In the journal title "Current biology", "Biology" should be capitalized.

 

Lines 430-431 -- In the journal title "Landscape ecology ", "Ecology" should be capitalized.

 

Line 433 -- In the journal title "Molecular ecology ", "Ecology" should be capitalized.

 

Line 451 -- The correct format for this journal name is Annual Review of Ecology, Evolution, and Systematics.

 

Line 452 -- "Ecology letters" should be "Ecology Letters".

 

Lines 454-455 -- There citation information missing in the 'References' entry for paper by Phillips et al. (2004). The paper/chapter is listed as being included in a volume entitled, "Proceedings of the twenty-first international conference on Machine learning (p. 83)" -- note: the volume title should be italicized. However, there are several details of this publication that are missing (e.g.: the page range for the Phillips et al. (2004) paper (i.e., if p. 83 is the start of the paper, what is the last page of the paper?); name(s) of the editor(s) of the Proceedings volume; the volume's publisher; etc.).

 

Lines 462-463 -- The Korstjens & Hillyer (2016) chapter is included in an edited volume, An Introduction to Primate Conservation (pp. 175-192) -- note the capitalization of the volume's title. But, that source citation information is incomplete -- while a title of the source volume is given, details regarding the volume's editors (i.e., S. Wich and A. Marshall) is missing, as is information about the publisher of the volume. That information *needs* to be included.

 

Line 476 -- 

"Primate conservation" should be Primate Conservation.

 

Line 481 -- There is a typographic error here in the taxonomic name for the 

Sichuan snub-nosed monkey -- (Rhi-nopithecus roxellana) should be (Rhinopithecus roxellana).

 

Line 484 & Line 486 -- "Science of the total environment" should be Science of the Total Environment.

 

Line 487 -- 

"Climatic change" should be Climatic Change.

 

Line 491 -- 

"Medical and veterinary entomology" should be Medical and Veterinary Entomology.  

 

Lines 492-493 -- "Ecological modelling" should be Ecological Modelling. 

 

Line 498 -- Following from the suggested inclusion of Dunbar (1998), that source should be inserted as citation [41]:

Dunbar RIM. (1998). Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach. Global Change Biology 4(3): 293-304.

The McCain (2007) source then becomes source [42]. 

 

Line 499 -- "Global Ecology and biogeography" should be Global Ecology and Biogeography.

 

Line 500 -- With the inclusion of Dunbar (1998) paper in the list of references (see comment above), this paper by Kujala et al. (2013) goes from being source [42] to source [43].

 

Line 501 -- "PloS one" should be PLOS One.

 

 

 

 

Comments on the Quality of English Language

As noted above, there are only minor editorial changes recommended to improve the quality of the English language presentation.

Author Response

Reviewer #1

Comment: This paper is important because it focuses on habitat suitability and geographic distribution of the Endangered (EN) Gaoligong (or, Skywalker) hoolock gibbon ('Hoolock tianxiang') under predicted environmental conditions for future climatic projections. So, thinking about this Endangered (or, potentially, Critically Endangered - CR) species under future climatic regimes and habitat conditions is important for advancing the conservation efforts for this species.

That said, there are several points through the paper where corrections to the text are recommended. Most of these remarks are minor and "editorial" in nature (e.g., correcting grammar). But, in a couple of cases, the theoretical context of the paper could have been better grounded -- the paper could be better "positioned" within the context of similar research at the interface of climate/environmental change and the viability of wildlife populations under future climatic regime conditions. These specific recommendations are presented below (by line number(s)).

Response: Thank you very much for taking the time to review and revise our paper. We truly appreciate your meticulousness and professionalism. We have carefully revised the paper based on your suggestions.. All changes have been highlighted in blue.

Abstract, Line 19: "Gaoligong Hoolock Gibbons (Hoolock tianxing)" -- 'Gaoligong' is correctly capitalized because it is a regional place name.  However, "Hoolock Gibbons" are not proper names. The passage on line 19 should read, "Gaoligong hoolock gibbons (Hoolock tianxing)".

Response: Thank you for your comment. We have updated the name in all the manuscript.

Abstract -- closing line (Line 38): To increase the impact to the 'Abstract', this closing phrase could be slightly reworded to read, "... the long-term survival of the Skywalker hoolock gibbons." Use of the widely recognized common name 'Skywalker gibbon' in the paper's Abstract would increase the profile and public recognition of this important report.

Response: Thank you for your comment. We have revised this name. Please see line 38-39.

Introduction, Lines 59-60: "Understanding how climate change affects species distributions is essential for predicting future biodiversity trends and identifying priority conservation areas."  This statement could (or should) be linked to the key concept of latent extinction risk (see "Latent extinction risk and the future battlegrounds of mammal conservation" by Marcel Cardillo, Georgina M. Mace, John L. Gittleman, and Andy Purvis, (2006). PNAS 103 (11): 4157–4161. www.pnas.org; doi: 10.1073 pnas.0510541103). Linking the information in the submitted Geng et al. manuscript to the existing theory concerning future biodiversity conservation (e.g., Cardillo et al., 2006) would more firmly situate the submitted manuscript within the larger conservation biology context.

Response: Thank you for your comment. We have rewritten this passage and cited the important reference of Cardillo et al., 2006. Now it reads like this: “Understanding how climate change affects species distributions is essential for predicting future biodiversity trends, identifying priority conservation areas, and evaluating latent extinction risks.”

REF: Cardillo, M., Mace, G. M., Gittleman, J. L., & Purvis, A. (2006). Latent extinction risk and the future battlegrounds of mammal conservation. Proceedings of the National Academy of Sciences, 103(11), 4157-4161.

Please see line line 60-63.

Introduction, Lines 70-71: "This knowledge is vital for creating adaptive management plans that support the long-term survival of species in a rapidly changing world." -- See my previous comment. There is certainly the larger theoretical framework of 'Latent Extinction Risk' within which to position this research report.

Response: Thank you for your comment. We have rewritten this passage. Now it reads like this: “This knowledge is vital for creating adaptive management plans that support the long-term survival of species in a rapidly changing world, particularly in the context of latent extinction risks, which highlight the hidden vulnerabilities of species under climate change.”

REF: Cardillo, M., Mace, G. M., Gittleman, J. L., & Purvis, A. (2006). Latent extinction risk and the future battlegrounds of mammal conservation. Proceedings of the National Academy of Sciences, 103(11), 4157-4161.

Please see line 72-76.

Introduction, Line 83: re. "Primates are highly sensitive to environmental changes, ...". This is a blanket statement that I think needs to be qualified. This is because not all primate species are, "... highly sensitive to environmental changes, ...". Although the Gaoligong hoolock gibbons are highly reliant on montane forest formations, there are numerous primate species that exhibit high behavioural and ecological flexibility and resilience to anthropogenic habitat change; some primate species even exhibit some degree of commensalism with human populations. The case of Hoolock tianxing relying on quite specific environmental conditions (reflecting a relatively narrow econiche) is not the "species profile" of many primate species that exhibit broader, more flexible econiches.

Response: Thank you for your comment. It definitely makes sense. We have made it specified. Now it reads like this: “Arboreal primates are highly sensitive to environmental changes, making them particularly vulnerable to the impacts of climate change.”

Please see line 87-88.

Introduction, Line 87: "... Gaoligong Hoolock Gibbon..." should be, "... Gaoligong hoolock gibbon...".

Response: Thank you for your comment. We have updated.

Introduction, Line 91: "... gibbons." should be "... Gaoligong hoolock gibbons." 

Response: Thank you for your comment. We have updated.

Introduction, Line 92: re. - "... Gaoligong Hoolock Gibbons, ..." -- "Hoolock" should be "hoolock", and "Gibbons" should be "gibbons". These same changes should also be made on Line 99 and Line 104.

Response: Thank you for your comment. We have updated.

Introduction, Line 111: re. - "... the gibbons..." -- More specific wording regarding the biological identity of the specific gibbon species is warranted here because there are multiple gibbon taxa that occur in China. Replace "... the gibbons..." with, "... for Gaoligong hoolock gibbons...". 

Response: Thank you for your comment. We have updated.

Introduction, Line 111: re. - "... China..." -- Revise to read, "... China's western Yunnan Province...".

Response: Thank you for your comment. We have updated. Please see line 117.

Introduction, Line 113: re. - "... on their habitat suitability..." -- For clarity, replace "their" with "gibbon". 

Response: Thank you for your comment. We have updated.

Materials and Methods, Lines 131-132: re. - "The study area is rich in primate resources, hosting 12 species of primates, ...".I suggest slight re-phrasing here, to read, "The study area is rich in primate taxa, hosting 12 species of primates, ...". 

Response: Thank you for your comment. We have updated. Please see line 137-138.

Materials and Methods, Line 140: Be specific here -- revise "... daily movement distance of primates... " to read, "... daily movement distance of Gaoligong hoolock gibbons...".

Response: Thank you for your comment. We reviewed the literature but could not find specific data on the daily movement distance of Gaoligong hoolock gibbons, as we referred to the daily movement distance of arboreal primates, specifically the Sichuan golden snub-nosed monkey.

Materials and Methods, Lines 142-143: re. composition of "Figure 1" -- The dark blue dots indicating the sighting/presence of Hoolock tianxing are *very* difficult to see against the background (i.e., habitat) colours on this map. Bright pink dots would show up much more clearly.

Response: Thank you for your comment. We have updated the colour to oink of Figure 1. Please see Figure 1 in the manuscript.

Section 3.2 - Habitat distributions under different climatic scenarios: 

Lines 227-228: re., "... scenarios were shown in Figures 3a and 4, ..." -- "were" should be "are".

Response: Thank you for your comment. We have updated. Please see line 239.

Section 3.3 - Altitudinal distribution of habitats across varying climatic scenarios:

Lines 259-262 -- re., "In contrast, mid-elevation areas (2396–2996m) gradually emerged as core habitats, with the proportion of suitability increasing markedly across all future scenarios. Similarly, Similarly, mid-high elevation areas...". A similar prediction of future "ecological retreat" by another high altitude primate species (i.e., the gelada (Theropithecus gelada), endemic to Ethiopia's Simien Mountains ) because of altitudinal shifts in vegetation and changing suitability in habitats could be cited here -- see: Dunbar, R.I.M. (1998). "Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach". Global Change Biology 4(3): 293-304.

Response: Thank you for your comment. Since this is the results section, we did not cite any references here. However, we appreciate the valuable references provided by the reviewer.

Section 3.4 - Distribution of ecological corridors, Line 269 -- re., "... climatic scenario, the species’ ecological corridors...". The phrasing here is awkward. Use of the term " species' " could be read as a plural possessive, even though the authors are just referring to a single species. A slight re-wording to this phrase could clear up this problem: "... climatic scenario, ecological corridors available to the species were primarily...". 

Response: Thank you for your comment. We have updated this. Now it reads like this: “Under the current climatic scenario, ecological corridors available to the species were were primarily distributed in the southern regions.” Please see line 282-283.

Line 272 - See previous comment... the same applies here concerning use of the term " species' ". Alternative phrasing could be, "... scenarios, ecological corridors for the species showed...".

Response: Thank you for your comment. We have updated this. Now it reads like this: “By 2070s, under all three RCP scenarios, ecological corridors for the species showed an increasing trend in resistance, a decrease in dispersal path density, and weakened connectivity.” Please see line 285-287.

Section 4.1 - Impacts of climatic variables and habitat suitability patterns:

Lines 290-291 - re. the phrase "... essential for the species’ survival and reproduction." -- See the two previous comments. Rephrase the passage to read, "... essential for the survival and reproduction of the species."

Response: Thank you for your comment. We have updated. Now it reads like this: “These factors significantly influenced the thermal and hydrological conditions essential for the survival and reproduction of the species.” Please see line 304-305.

Line 295-296 - re. the phrase, "... demonstrated the species’ acute sensitivity...". Rephrase this passage to read, "... demonstrated the acute sensitivity of H. tianxing...". 

Response: Thank you for your comment. We have updated. Now it reads like this: “The observed shifts in habitat suitability along elevation gradients demonstrated the acute sensitivity of H. tianxing to temperature increases and precipitation variability, which were amplified under high-emission scenarios such as RCP 8.5.” Please see line 310-311.

Line 299 - re. source citation '[41]': Another relevant source citation that could be made here is:

Dunbar, R.I.M. (1998). Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach. Global Change Biology 4(3): 293-304.

This would mean the source originally cited here (i.e., [41] -- McCain, 2007) would become source [42].

Response: Thank you for your valuable suggestion. We have cited the important reference here.

REF: Dunbar, R.I.M. (1998). Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach. Global Change Biology, 4(3), 293-304.

Line 307 - Revise the phrase, "... climate change on the gibbons ..." to read, "... climate change on the Gaoligong gibbons...".

Response: Thank you for your comment. We have updated.

Line 307 - Following the insertion of the Dunbar (1998) source here, the source citation number here (i.e., [42]) should be changed to [43].

Response: So considerable of you. Thanks. Updated.

Section 4.2 - Habitat decline under future climate scenarios:

Line 310 -- re. - "... gibbons."; Revise to read, "... Gaoligong gibbons.".

Response: Thank you for your comment. We have updated.

Line 312 -- re. - "... threat posed by global warming to habitat availability..."; Revise to read, "... threat posed by global warming to Gaoligong gibbon habitat availability...".

Response: Thank you for your comment. We have updated.

Line 316 -- re. See previous comments concerning the problematic nature of using "species" in the possessive (i.e., species'). Rephrase the passage to read, "... highlighting the reliance of Gaoligong gibbons on cooler and more stable microclimates...". 

 Response: Thank you for your comment. We have updated.

Line 327 -- re. the phrase, "... long-term survival of the gibbons...". Reword to read, "... long-term survival of the Gaoligong gibbons...".

 Response: Thank you for your comment. We have updated.

Section 4.3 - Fragmentation and connectivity of ecological corridors:

Line 331 -- re. the phrase, "... for the gibbons...". Replace "the" with "Gaoligong" -- i.e., "... for Gaoligong gibbons...".

 Response: Thank you for your comment. We have updated.

Line 340 -- re. use of the term "extinctions" -- The more precise term to use here would be "extirpations", rather than "extinctions".

 Response: Thank you for your comment. We have updated.

Line 340 -- re. the closing phrase to the sentence: "... the species’ long-term survival." Reword this phrase to read: "... the long-term survival of the species."

 Response: Thank you for your comment. We have updated.

Lines 353-354 -- Replace "... local extinctions..." with "... extirpations...".

Response: Thank you for your comment. We have updated.

Section 4.4 - Conservation strategies and cross-border collaboration:

Line 358 -- Revise "...the gibbons," to read "... the Gaoligong gibbons...".

Response: Thank you for your comment. We have updated.

Line 365 -- Instead of "observed", a better word to use here would be "predicted".

Response: Thank you for your comment. We have updated.

Lines 368-370 -- re., "The establishment of green corridors or stepping stones has been shown to enhance connectivity and mitigate the effects of habitat fragmentation on species persistence."  Backing this statement up with a source citation or two would be worthwhile.

Response: Thank you for your comment. We have cited the related references. Please see line 397-389.

Lines 371-372 -- re., "... the gibbon populations remain...". Rephrase this to read, "... the Gaoligong gibbon populations...".

Response: Thank you for your comment. We have updated.

Line 383 -- re., "... of the gibbons.". Revise to read, "... of the Gaoligong gibbons."

Response: Thank you for your comment. We have updated.

Conclusions, Line 386: re. "... the gibbons..." -- Revise this phrase to specify "... the Tianxiang hoolock gibbons...".

Response: Thank you for your comment. We have updated.

Conclusions, Lines 387-388: re. "... revealed that key climatic variables, including elevation, temperature range, seasonality, and precipitation, play a critical role...". The phrasing of this sentence includes a plural ("variables") to singular ("... a critical role...") tense shift that needs to be corrected. This sentence includes a tense shift -- you go from the plural voice (i.e., "... climatic variables..."), to speaking in the singular (i.e., ".. play a critical role..."). To  correct this, the wording of the entire sentence should also be in the plural voice (i.e., "... climatic variables... play critical roles...").

 Response: Thank you for your comment. We have updated. Now it reads like this: Our findings revealed that key climatic variables, including elevation, temperature range, seasonality, and precipitation, play critical roles in determining the suitability of habitats for the species. Please see line 406-408.

Conclusions, Line 391 -- re.: the phrase, "... scenario, where habitat area could decrease...". This phrase needs to be revised to be more precise. Replace "... where habitat area could decrease...", with, "... where suitable habitat areas could decrease...". 

Response: Thank you for your comment. We have updated. Now it reads like this: Under future climate scenarios, we projected a significant decline in suitable habitat, with the most pronounced loss occurring under the high-emission RCP8.5 scenario, where suitable habitat areas could decrease by as much as 69%. Please see line 408-411.

Conclusions, Line 396 -- Replace "...local extinctions." with "... extirpations.".

Response: Thank you for your comment. We have updated.

Conclusions, Line 402 -- Replace "... gibbons." with "... Gaoligong hoolock gibbons."

Response: Thank you for your comment. We have updated.

References section -- There are several irregularities and stylistic errors in the list of "References" that need to be addressed/corrected. For example, all the journal names and book titles of the sources you identify in the list of 'References' should be italicized.

In addition, the following elements of the 'References' section of the manuscript need to be corrected or revised:

Response: Thank you for your comment. We have updated the related references.

 

Line 422 -- In the journal title "Ecology letters", "Letters" should be capitalized.

Response: Thank you for your comment. We have updated.

Line 429 -- In the journal title "Current biology", "Biology" should be capitalized.

Response: Thank you for your comment. We have updated.

Lines 430-431 -- In the journal title "Landscape ecology ", "Ecology" should be capitalized.

Response: Thank you for your comment. We have updated.

Line 433 -- In the journal title "Molecular ecology ", "Ecology" should be capitalized.

Response: Thank you for your comment. We have updated.

Line 451 -- The correct format for this journal name is Annual Review of Ecology, Evolution, and Systematics.

Response: Thank you for your comment. We have updated.

Line 452 -- "Ecology letters" should be "Ecology Letters".

Response: Thank you for your comment. We have updated.

Lines 454-455 -- There citation information missing in the 'References' entry for paper by Phillips et al. (2004). The paper/chapter is listed as being included in a volume entitled, "Proceedings of the twenty-first international conference on Machine learning (p. 83)" -- note: the volume title should be italicized. However, there are several details of this publication that are missing (e.g.: the page range for the Phillips et al. (2004) paper (i.e., if p. 83 is the start of the paper, what is the last page of the paper?); name(s) of the editor(s) of the Proceedings volume; the volume's publisher; etc.).

Response: Thank you for your comment. We have updated. Now it reads like this:

Phillips, S.J.; Dudík, M.; Schapire, R.E. A maximum entropy approach to species distribution modeling. In Proceedings of the 21st International Conference on Machine Learning; ACM Press: New York, NY, USA, 2004; pp. 655–662.

Lines 462-463 -- The Korstjens & Hillyer (2016) chapter is included in an edited volume, An Introduction to Primate Conservation (pp. 175-192) -- note the capitalization of the volume's title. But, that source citation information is incomplete -- while a title of the source volume is given, details regarding the volume's editors (i.e., S. Wich and A. Marshall) is missing, as is information about the publisher of the volume. That information *needs* to be included.

Response: Thank you for your comment. We have updated. Now it reads like this:

Korstjens AH, Hillyer AP. Primates and climate change: a review of current knowledge. In: SA Wich, AJ Marshall, eds. An Introduction to Primate Conservation. Oxford University Press; 2016, 175-192.

Line 476 -- "Primate conservation" should be Primate Conservation.

Response: Thank you for your comment. We have updated.

Line 481 -- There is a typographic error here in the taxonomic name for the 

Sichuan snub-nosed monkey -- (Rhi-nopithecus roxellana) should be (Rhinopithecus roxellana).

Response: Thank you for your comment. We have updated.

Line 484 & Line 486 -- "Science of the total environment" should be Science of the Total Environment.

Response: Thank you for your comment. We have updated.

Line 487 -- "Climatic change" should be Climatic Change.

Response: Thank you for your comment. We have updated.

Line 491 -- "Medical and veterinary entomology" should be Medical and Veterinary Entomology.  

Response: Thank you for your comment. We have updated.

Lines 492-493 -- "Ecological modelling" should be Ecological Modelling. 

Response: Thank you for your comment. We have updated.

Line 498 -- Following from the suggested inclusion of Dunbar (1998), that source should be inserted as citation [41]:

Dunbar RIM. (1998). Impact of global warming on the distribution and survival of the gelada baboon: a modeling approach. Global Change Biology 4(3): 293-304.

The McCain (2007) source then becomes source [42]. 

Response: Thank you for your comment. We have updated the order of the reference list.

Line 499 -- "Global Ecology and biogeography" should be Global Ecology and Biogeography.

Response: Thank you for your comment. We have updated.

Line 500 -- With the inclusion of Dunbar (1998) paper in the list of references (see comment above), this paper by Kujala et al. (2013) goes from being source [42] to source [43].

Response: Thank you for your comment. We have updated.

Line 501 -- "PloS one" should be PLOS One.

Response: Thank you for your comment. We have updated.

Thanks again for your valuable comments.

Best regards,

The authors.

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review this paper. I congratulate the authors on the elegance of the research design and the clarity with which the results are presented. The paper contributes valuable information needed to ensure the continued survival of the critically endangered Gaoligong hoolock gibbon. I am happy to recommend it for publication, as written, with three minor suggestions.

The authors gathered 263 species distribution points (from direct and indirect evidence of gibbon occurrence). Based on current distribution, they modeled the extent and availability of future habitat considering nineteen bioclimatic variables and in the context of three emission scenarios. Strongly correlated bioclimatic variables were reduced, eventually leaving elevation, temperature annual range, temperature seasonality, annual precipitation, and annual precipitation range in the analysis. They also modeled habitat connectivity under these three different emission scenarios. They found that suitable gibbon habitat declined in all three scenarios, particularly at lower elevations. Habitat connectivity also decreased in each scenario, particularly in the southern part of the species’ range. The results are informative in protection of existing habitat and in establishing restoration priorities. The authors urge cross-border collaborative efforts with Myanmar to further safeguard the species.

The writing is clear, concise, and informative, and the figures help the reader understand the habitat changes being modeled. My suggestions are minor:

1. on line 129, I suggest changing “genetic flow” to “gene flow.’

2. on line 135, the authors refer to nest markings as evidence of gibbon occurrence, but gibbons do not to my knowledge build nests.

3. on line 180, I think there is a typo in that Bio17 and Bio7 are both described as Temperature Annual Range.

I wish authors good luck with their important research!

Comments for author File: Comments.pdf

Author Response

Reviewer #2

Comment: Thank you for the opportunity to review this paper. I congratulate the authors on the elegance of the research design and the clarity with which the results are presented. The paper contributes valuable information needed to ensure the continued survival of the critically endangered Gaoligong hoolock gibbon. I am happy to recommend it for publication, as written, with three minor suggestions.

The authors gathered 263 species distribution points (from direct and indirect evidence of gibbon occurrence). Based on current distribution, they modeled the extent and availability of future habitat considering nineteen bioclimatic variables and in the context of three emission scenarios. Strongly correlated bioclimatic variables were reduced, eventually leaving elevation, temperature annual range, temperature seasonality, annual precipitation, and annual precipitation range in the analysis. They also modeled habitat connectivity under these three different emission scenarios. They found that suitable gibbon habitat declined in all three scenarios, particularly at lower elevations. Habitat connectivity also decreased in each scenario, particularly in the southern part of the species’ range. The results are informative in protection of existing habitat and in establishing restoration priorities. The authors urge cross-border collaborative efforts with Myanmar to further safeguard the species.

The writing is clear, concise, and informative, and the figures help the reader understand the habitat changes being modeled. My suggestions are minor:

Response: Thank you for your recognition of our manuscript and for your professional revision suggestions. We have made the necessary revisions, and all changes have been highlighted in blue.

Comment:  on line 129, I suggest changing “genetic flow” to “gene flow.’

Response: Thank you for your suggestion. We have updated. Please see line 135.

Comment: on line 135, the authors refer to nest markings as evidence of gibbon occurrence, but gibbons do not to my knowledge build nests.

Response: Sorry for our careless. Thank you so much for your reminder. We have updated the sentence. Now it read like this: We collected a total of 263 species distribution points, with 249 of these points derived from field surveys, including observed individuals, foraging signs, and other direct evidence of species presence. Please see line 140-142.

Comment: on line 180, I think there is a typo in that Bio17 and Bio7 are both described as Temperature Annual Range.

Response: Sorry for our careless. We have corrected. It should be: Bio7 (Temperature Annual Range); Bio17 (Precipitation of Driest Quarter). We have updated all the related contents in the manuscript. Please see line 187-189; 229; 301-302.

Thanks again for your valuable comments.

Best regards,

The authors.