Use of Human Dominated Landscape as Connectivity Corridors among Fragmented Habitats for Wild Asian Elephants (Elephas maximus) in the Eastern Part of Thailand

Round 1

Reviewer 1 Report

This paper presents an assessment of potential corridors for use of wild elephants in Thailand.  While there are some worthwhile results, there are weaknesses that should be addressed:

1. The recommendations are not very specific, especially in terms of explaining or prioritizing corridors spatially. Discussion of results and how they might be implemented is also vague. It would be very difficult for land managers or decision makers to look at this paper, especially the maps, and get a clear idea about how to prioritize or implement any changes that would result in improved connectivity of the landscape for elephants.  There should be more detail and better illustrations to show the results.

2. In a similar way, the last sentence of the paper mentions human communities almost as an afterthought. These types of changes would have major impacts to communities, yet there is no discussion of that or how it might be handled. 

3. Most of the figures are too small and the resolution is too low to be readable or useful.  These have to be re-worked and provided in higher resolution. In many cases the maps need to be zoomed in more for them to be of any use:

- The legend in Figure 1 is unreadable. The country wide land use map in the upper left is also unreadable. Only the zoomed in section is somewhat useful, though it only seems to show only one type of land use. However, since it's nearly impossible to see what the land use categories are from the legend that portion is also unclear.

- The maps in Figures 2, 3, and 6 are very blurry and too small to read, and they are not very useful presented in this way. The resolution has to be improved and it might be necessary to focus on a few examples in Figures 2 and 3 rather than all the results. It might be better to focus on some results that illustrate important patterns so that the overall map size can be larger. Showing everything in a very small area isn't helpful for interpreting the results.

-  The text on Figure 4 and 5 graphs is completely illegible. There is no point in including these if they can't be read.

4. Methods and Results have no discussion of using any of the data for testing, or estimates of accuracy of the results.

5. Line 157: there is discussion of a Beier paper that gives very specific numbers about what size area is needed to support breeding of a "habitat generalist" over specific time periods. That is a big jump to use numbers on area needed for a generic species and apply it for elephants. It's also not explained clearly how this metric was used in the analysis. 

6. There areas where the language could be improved.  I've made detailed comments in the pdf attached.  A few other comments in that direction:

- Line 278 - "The population of wild elephants in the eastern part of Thailand was under estimated as found in other areas of Thailand"

I can't tell what this means, the estimates were lower than elsewhere, or they were incorrect and "underestimated"?

- Lines 302-305 - This is a run-on sentence and it is very difficult to follow.  Need to break it up and clarify the point/points being made.

- Paragraph staring line 337 - What is meant by "naturally made"?  Need to define and clarify what is meant here.  "Naturally" suggests to me that it is not through human involvement while "made" suggests otherwise.

- What is meant by "expropriation of the landscape to construct the linkage corridor"?  This is vague and off-handed given what is suggests, which would be taking away or changing land rights or access to land.

Overall, this is a worthwhile paper, though it has a lot of weaknesses. These could be strengthened with a thorough overhaul and consideration of the comments above.

 

 

Comments for author File: Comments.pdf

Author Response

Response to Comments and Suggestions for Authors of Reviewer #1

This paper presents an assessment of potential corridors for use of wild elephants in Thailand. While there are some worthwhile results, there are weaknesses that should be addressed:

1. The recommendations are not very specific, especially in terms of explaining or prioritizing corridors spatially. Discussion of results and how they might be implemented is also vague. It would be very difficult for land managers or decision makers to look at this paper, especially the maps, and get a clear idea about how to prioritize or implement any changes that would result in improved connectivity of the landscape for elephants. There should be more detail and better illustrations to show the results.

Response: Thank you for your comments. We reconstruct the Figures and give more details on results and used them for specific discussion.

 

2. In a similar way, the last sentence of the paper mentions human communities almost as an afterthought. These types of changes would have major impacts to communities, yet there is no discussion of that or how it might be handled.

Response: We explain as “The negotiation between the villagers and authorities on these problems must be solved by sit together and discuss about the benefit of migration of HEC along sides of the cor-ridors and other benefit that the land ownwer will gain from this conservation practice [73,74]” in line 338-341.

 

3. Most of the figures are too small and the resolution is too low to be readable or useful. These have to be re-worked and provided in higher resolution. In many cases the maps need to be zoomed in more for them to be of any use:

Response: We reconstruct the Figures.

 

- The legend in Figure 1 is unreadable. The country wide land use map in the upper left is also unreadable. Only the zoomed in section is somewhat useful, though it only seems to show only one type of land use. However, since it's nearly impossible to see what the land use categories are from the legend that portion is also unclear.

Response: We reconstruct the Figure 1 to show the distribution of forest areas in the eastern part of Thailand.

 

- The maps in Figures 2, 3, and 6 are very blurry and too small to read, and they are not very useful presented in this way. The resolution has to be improved and it might be necessary to focus on a few examples in Figures 2 and 3 rather than all the results. It might be better to focus on some results that illustrate important patterns so that the overall map size can be larger. Showing everything in a very small area isn't helpful for interpreting the results.

Response: We reconstruct the Figures.

 

- The text on Figure 4 and 5 graphs is completely illegible. There is no point in including these if they can't be read.

Response: We reconstruct Figure 4 and 5.

 

4. Methods and Results have no discussion of using any of the data for testing, or estimates of accuracy of the results.

Response: We explained as “The Based on the interviews, the presence of wild elephants has increased in seven provinces of the eastern part of Thailand. The AUC of SDMs in the dry season (AUC = 0.813) was greater than the wet season (AUC = 0.783), and was greater 0.7 that were suitable for explains the distribution of wild elephants in the area [48]” in line 285-287.

 

5. Line 157: there is discussion of a Beier paper that gives very specific numbers about what size area is needed to support breeding of a "habitat generalist" over specific time periods. That is a big jump to use numbers on area needed for a generic species and apply it for elephants. It's also not explained clearly how this metric was used in the analysis.

Response: We explained as “These criteria were used to identified the habitat patch in the CorridorDesigner for created habitat and corridor models with ArcGIS and an ArcMap extension for evaluated corridors [53]” in line 164-166.

 

6. There areas where the language could be improved. I've made detailed comments in the pdf attached. A few other comments in that direction:

Response: Thank you for your kindness.

 

- Line 278 - "The population of wild elephants in the eastern part of Thailand was under estimated as found in other areas of Thailand"

I can't tell what this means, the estimates were lower than elsewhere, or they were incorrect and "underestimated"?

Response: We changed to “The population of wild elephants in the eastern part of Thailand and other areas were incorrect and underestimated [58]” in line 287-289.

 

- Lines 302-305 - This is a run-on sentence and it is very difficult to follow. Need to break it up and clarify the point/points being made.

Response: We separated as “Roads had an influence on the attraction of wild elephants outside the forest area, especially during the dry season. In the past five years, while in the wet season the roads had less influence, as found in Nepal, where roads were the main environmental parameter affecting the distribution of wild elephants [66]” in line 314-318.

 

- Paragraph staring line 337 - What is meant by "naturally made"? Need to define and clarify what is meant here. "Naturally" suggests to me that it is not through human involvement while "made" suggests otherwise.

Response: We rewrote as “        To reduce the habitat suitability and risk in the area, the natural habitats and human made landscape corridors that are used by wild elephants can provide potential landscape corridors between habitat” in line 353-355.

 

- What is meant by "expropriation of the landscape to construct the linkage corridor"? This is vague and off-handed given what is suggests, which would be taking away or changing land rights or access to land.

Response: We changed to “Therefore, consideration should be given to the possibility of changing land of the landscape to construct the linkage corridor” in line 356-357.

 

Overall, this is a worthwhile paper, though it has a lot of weaknesses. These could be strengthened with a thorough overhaul and consideration of the comments above.

Response: Thank you for your kindness help to improve the manuscript.

 

PDF file:

has there been some change to the amount of habitat suitability in the area?

Response: We changed to “Landscape connectivity has potential effects on survival, fitness, gene flow, diversity, and colonization of distinct small populations [27,28] and has been changed the habitat suitability in the area” in line 55-57.

 

What is seen - corridors or megafauna? Frequently seen by who?  Not sure what this sentence means here.

Response: We changed to “Corridors are a key element of wildland conservation, which are the conjunction for the iconic megafauna whose populations they are intended to conserve” in line 71-73.

 

not sure what is meant by "designated distribution of distance"

Response: We rewrote as “based on the assumption that movement of elephant occurs between proximate occurrence points within a designated distribution of elephants in the corridors” in line 86-88.

 

Can you say more here regarding how much they increased?

Response: We added “The distance from the road mostly <4 km, the reservoir <12 km. The agricultural areas in the eastern part of Thailand were para rubbers and fruit orchards in the southern, Eucalyptus in the northwestern, and the cassava and the maize in the northeastern” in line 196-199.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authours,

I need a suitable version of the manuscript previous review, because Figures 3-6 cannot be seen and a I cannot review the manuscript properly.

 

However, I send you some minor comments in advance:

LINE 50. Large predators? How elephants are influenced by large predators?

LINE 302-305. This may be due to roads are the main places where people go and can observe animals, so may be due to an anthropic bias.

LINE 317-318. Reference for this statement is required.

Author Response

Response to Comments and Suggestions for Authors of Reviewer #2

Dear authours,

I need a suitable version of the manuscript previous review, because Figures 3-6 cannot be seen and a I cannot review the manuscript properly.

Response: Sorry for unsuitable Figures, we reconstruct the Figures.

However, I send you some minor comments in advance:

Response: Thank you for your kindness.

LINE 50. Large predators? How elephants are influenced by large predators?

Response: We added “…even, elephants are not the proper food choice of tiger but eight case were recorded in Corbett Tiger Reserve [26]” in line 53-54.

LINE 302-305. This may be due to roads are the main places where people go and can observe animals, so may be due to an anthropic bias.

Response: We explained as “However, elephants were attracted to the road in the more abundant of secondary forest and open habitats that contain more food sources [67]” in line 318-319.

LINE 317-318. Reference for this statement is required.

Response: We changed to “Due to their extensive use of ecosystems, corridors for elephants also benefit other species. Therefore, maintaining connectivity for elephants helps maintain connectivity for other species [71]” in line 331-333.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors identified suitable corridors for connecting fragmented habitat for Asian elephants in east Thailand. They produced relevant outcome based on data for 2020. Their findings are crucial for informing the conservation management of an iconic species in the face of increasing conflicts. However, the authors have also chosen to include data from earlier than 2020 that are outside the manuscript’s aim.

 

Also, the authors have reported the Asian elephant distribution and conflicts in another article of theirs (in press). I suggest that the authors remove all irrelevant information and focus on suitable habitat corridors. Please remove the following and all relevant text in the manuscript:

--Figure 2. The change in land use has been reported before and does not add to the present manuscript.

--Figure 3. Keep only 3e; resistance maps for 2020.

---Figures 4 and 5. They are redundant. Give brief information about model performance and important factors in the text.

--Table 1. Redundant. Give relevant references in the text.

--Table 2. Keep only data for 2020.

 

Figures 3e, 6 and Tables 3, 4, 5 tell your story. Give relative supporting information in the Introduction, give methods and analyses for these data in detail. Be specific and clear in results. Discuss the findings about important corridors and expand on their use for the conservation of Asian elephants and the management of conflict.

 

Maps in all the figure are not readable. New maps should be produced where the reader will be able to discern colors, corridors, legends, etc. Further suggestions could be made after reviewing new figures.

 

Other comments

---Lines 11-23 – Focus on your main findings; the number of suitable corridors for connected finest Asian elephant habitats.

---Lines 16-20 – It is not clear to which year these findings refer to.

---Lines 22-23 – Make a closing statement connected to your results.

---Lines 35-38 – Please make a special reference to your in press article here, giving main relevant findings.

---Line 39 – connectivity of wild elephants is lost…

---Lines 102-103 – Wettasin et al., 2022, in press is not in the references list. Please add.

---Line 106 – above sea level…

---Lines 132-157 – Move this text to Introduction.

---Line 159 – I think it should be a population patch, not a habitat patch. All three are habitat patches (see line 157). Please review and correct.

---Lines 277-316 – This text is not directly connected to your findings. The discussion of the trends in land use and conflict should be removed. A brief comment on the major factors that determined Asian elephant distribution in 2020 could be made.

---Lines 317-324, 328-351 – This text on wildlife corridors is relevant. Please capitalize on this. Discuss your findings of important habitat patches and identified corridors. Relate them to relevant research. Propose methods for the creation and maintenance of suitable corridors for conserving Asian elephants and reducing human-elephant conflict in east Thailand.

Author Response

Response to Comments and Suggestions for Authors of Reviewer #3

 

The authors identified suitable corridors for connecting fragmented habitat for Asian elephants in east Thailand. They produced relevant outcome based on data for 2020. Their findings are crucial for informing the conservation management of an iconic species in the face of increasing conflicts. However, the authors have also chosen to include data from earlier than 2020 that are outside the manuscript’s aim.

Response: We remove all data from earlier than 2020.

 

Also, the authors have reported the Asian elephant distribution and conflicts in another article of theirs (in press). I suggest that the authors remove all irrelevant information and focus on suitable habitat corridors. Please remove the following and all relevant text in the manuscript:

--Figure 2. The change in land use has been reported before and does not add to the present manuscript.

Response: We remove all irrelevant information. And Figure 2 We remove the land used changed and kept only 2020.

 

--Figure 3. Keep only 3e; resistance maps for 2020.

Response: We Kept only the resistance maps for 2020.

 

---Figures 4 and 5. They are redundant. Give brief information about model performance and important factors in the text.

Response: We added “The jackknife training grain was used to evaluate the associations between environmental parameters and the distribution of wild Asian elephants in the eastern part of Thailand. In the wet season, the wild elephants tended to live in the protected areas rather than en-tering agricultural areas (Figure 4). The suitable SDMs were evaluated by AUC <0.7. Therefore, the AUC in all maps were higher than 0.7, indicating that the SDMs were suitable for explains the distribution of wild elephants in the area (Figure 5).” in line 210-216.

 

--Table 1. Redundant. Give relevant references in the text.

Response: We gave the relevant references in the text and deleted Table 1.

 

--Table 2. Keep only data for 2020.

Response: We changed Table 2 to Table 1 and kept only data for 2020.

 

Figures 3e, 6 and Tables 3, 4, 5 tell your story. Give relative supporting information in the Introduction, give methods and analyses for these data in detail. Be specific and clear in results. Discuss the findings about important corridors and expand on their use for the conservation of Asian elephants and the management of conflict.

Response: We rewrite by follow your comments.

 

Maps in all the figure are not readable. New maps should be produced where the reader will be able to discern colors, corridors, legends, etc. Further suggestions could be made after reviewing new figures.

Response: We reproduce the figures.

 

Other comments

---Lines 11-23 – Focus on your main findings; the number of suitable corridors for connected finest Asian elephant habitats.

Response: We rewrote as “Habitat fragmentation from human activities creates threats to wild Asian elephants (Elephas maximus) and increases human-elephant conflicts (HEC). This study analyzed connectivity maps among the core habitats of wild elephants in the eastern part of Thailand. Resistance surfaces were used to estimate dispersal of wild elephants associated with geographic and land use features. An increase in roads, reservoirs, and agricultural areas in 2020 was noted. In addition, the increase of artificial water sources and roads have increased HEC. To reduce HEC, the study of the suitable landscape corridors for wild Asian elephants can guide the development of effective connecting among the habitat patches. The scattered locations of reserved forests induce wild elephants to enter the agricultural areas. In 2020, the dry season, wild elephants used 3,552 habitat patches; 253 population patches (4,875 km2), 8 breeding patches (68.1 km2) and 253 other patches (193.9 km2), while habitat patches were reduced to 1,961 patches (3,850.9 km2) in the wet season. The 16 suitable corridors were recommended for connected finest wild Asian elephants. These suitable corridors can use as a guideline to construct of the effective landscape corridors among the habitat patches for wild Asian elephants movement among habitat patches. This finding can help the local managers and villagers to incorporate and design the restoration areas for the movements and survival of wild Asian elephants and suitable areas for agricultural areas development” in line 11-25.

 

---Lines 16-20 – It is not clear to which year these findings refer to.

Response: In 2020.

 

---Lines 22-23 – Make a closing statement connected to your results.

Response: We rewrote the Abstract as “This finding can help the local managers and villagers to incorporate and design the restoration areas for the movements and survival of wild Asian elephants and suitable areas for agricultural areas development” in line      .

 

---Lines 35-38 – Please make a special reference to your in press article here, giving main relevant findings.

Response: We added “The level of conflict is increasing follow by the increasing of human activities as found in previous studied by Wettasin et al. [15]” in line 40-41.

 

---Line 39 – connectivity of wild elephants is lost…

Response: We changed to “This phenomenon is increasingly concerning, especially when the ecological connectivity of wild elephants is reduced [16,17]” in line 41-42.

 

---Lines 102-103 – Wettasin et al., 2022, in press is not in the references list. Please add.

Response: We added as “Data on the occurrence of wild elephants outside the protected areas was based on snowball sampling of 183 households between 2020-2021 [15] and in the protected areas conducted by DNP [35]” in line 118-120.

 

---Line 106 – above sea level…

Response: We change to “…above sea level…”

 

---Lines 132-157 – Move this text to Introduction.

Response: We move to Introduction in line 64-77.

 

---Line 159 – I think it should be a population patch, not a habitat patch. All three are habitat patches (see line 157). Please review and correct.

Response: We changed to “population patch” in line 156.

 

---Lines 277-316 – This text is not directly connected to your findings. The discussion of the trends in land use and conflict should be removed. A brief comment on the major factors that determined Asian elephant distribution in 2020 could be made.

Response: We rewrote this part.

 

---Lines 317-324, 328-351 – This text on wildlife corridors is relevant. Please capitalize on this. Discuss your findings of important habitat patches and identified corridors. Relate them to relevant research. Propose methods for the creation and maintenance of suitable corridors for conserving Asian elephants and reducing human-elephant conflict in east Thailand.

Response: We rewrote this part.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

I consider that the authours have adresseed all my suggestions properly, so the manuscript can be accepted in present form.

Author Response

Dear Reviewer,

Thank you for your valuable comments.

Best regards,

Reviewer 3 Report

The authors have successfully addressed the reviewers' comments.

However, extensive editing of the English language is required before publication.

Author Response

Dear Reviewer,

Thank you for your valuable comments.

We were edited our English by native speaker.

Best regards,