Sustainable elk harvests in Alberta with increasing predator populations

Tyler Trump; Kyle Knopff; Andrea Morehouse; Mark S. Boyce

doi:10.1371/journal.pone.0269407

Peer Review History

Original SubmissionMay 17, 2022
17 May 2022 Author Response Attachments Attachment Submitted filename: Responses to reviewer comments.docx https://doi.org/10.1371/journal.pone.0269407.r001
16 Aug 2022 Decision Letter - Avanti Dey, Editor PONE-D-22-14168Sustainable elk harvests in Alberta with increasing predator populationsPLOS ONE Dear Dr. Boyce, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Can you please address the concerns raised by the expert reviewer? Please submit your revised manuscript by Sep 29 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Avanti Dey, PhD Staff Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. We note that you have stated that you will provide repository information for your data at acceptance. Should your manuscript be accepted for publication, we will hold it until you provide the relevant accession numbers or DOIs necessary to access your data. If you wish to make changes to your Data Availability statement, please describe these changes in your cover letter and we will update your Data Availability statement to reflect the information you provide 3. We note that Figure 1 in your submission contain [map/satellite] images which may be copyrighted. All PLOS content is published under the Creative Commons Attribution License (CC BY 4.0), which means that the manuscript, images, and Supporting Information files will be freely available online, and any third party is permitted to access, download, copy, distribute, and use these materials in any way, even commercially, with proper attribution. For these reasons, we cannot publish previously copyrighted maps or satellite images created using proprietary data, such as Google software (Google Maps, Street View, and Earth). For more information, see our copyright guidelines: http://journals.plos.org/plosone/s/licenses-and-copyright. We require you to either (1) present written permission from the copyright holder to publish these figures specifically under the CC BY 4.0 license, or (2) remove the figures from your submission: 1. You may seek permission from the original copyright holder of Figure 1 to publish the content specifically under the CC BY 4.0 license. We recommend that you contact the original copyright holder with the Content Permission Form (http://journals.plos.org/plosone/s/file?id=7c09/content-permission-form.pdf) and the following text: “I request permission for the open-access journal PLOS ONE to publish XXX under the Creative Commons Attribution License (CCAL) CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). Please be aware that this license allows unrestricted use and distribution, even commercially, by third parties. Please reply and provide explicit written permission to publish XXX under a CC BY license and complete the attached form.” Please upload the completed Content Permission Form or other proof of granted permissions as an "Other" file with your submission. In the figure caption of the copyrighted figure, please include the following text: “Reprinted from [ref] under a CC BY license, with permission from [name of publisher], original copyright [original copyright year].” 2. If you are unable to obtain permission from the original copyright holder to publish these figures under the CC BY 4.0 license or if the copyright holder’s requirements are incompatible with the CC BY 4.0 license, please either i) remove the figure or ii) supply a replacement figure that complies with the CC BY 4.0 license. Please check copyright information on all replacement figures and update the figure caption with source information. If applicable, please specify in the figure caption text when a figure is similar but not identical to the original image and is therefore for illustrative purposes only. The following resources for replacing copyrighted map figures may be helpful: USGS National Map Viewer (public domain): http://viewer.nationalmap.gov/viewer/ The Gateway to Astronaut Photography of Earth (public domain): http://eol.jsc.nasa.gov/sseop/clickmap/ Maps at the CIA (public domain): https://www.cia.gov/library/publications/the-world-factbook/index.html and https://www.cia.gov/library/publications/cia-maps-publications/index.html NASA Earth Observatory (public domain): http://earthobservatory.nasa.gov/ Landsat: http://landsat.visibleearth.nasa.gov/ USGS EROS (Earth Resources Observatory and Science (EROS) Center) (public domain): http://eros.usgs.gov/# Natural Earth (public domain): http://www.naturalearthdata.com/ Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: I believe you did a nice job using existing data to address an important management issue that has implications for large mammal management across North America. Throughout large portions of western North America, concerns exist as to the effects of recovering predator populations on ungulate populations. You address this question as it pertains to predator and elk populations in Alberta. I like that you did not focus only on the area(s) where predator effects are hypothesized to be greatest (e.g., Zone 4 in your study), but instead looked at Alberta as a whole to provide a more complete picture. I made a number of edits below that I believe should be addressed prior to publication. Most important, please note my concerns below about the Management Implications section; I think you should remove references to other ungulates and apparent competition as this goes beyond the scope of the paper. Lines 26, 41: I believe elk scientific name changed to Cervus canadensis Lines 29-32: I strongly suggest rewording these two sentences so it’s clear you are reporting rates of increase. When I first read the sentence on hunter success, I thought you were saying average hunter success was 0.2% or 0.3% per year (as opposed to increasing by that amount per year). I suggest rewording as: “Over a 26-yr period, average harvest of elk increased by 5.46% per year for unrestricted bull and by 6.64% per year for limited-quota seasons. Also, over the same time frame, average hunter success increased by 0.2% per year for unrestricted bull and by 0.3% per year for limited-quota seasons, but no trend was detected in hunter effort (P>0.05).” Lines 48-49: Be more specific with this statement or I suggest deleting it. Is this statement specific to Alberta, or Canadian provinces in general? If so, say as much. For many state agencies in the western US, analysis of harvest data is the basis for elk harvest management decisions. These analyses aren’t always published in the peer-reviewed literature, but they happen nonetheless, often by biometricians hired by the agencies to do that very thing. The cited paper (Yoccoz et al 2001) is not sufficient to support your statement (i.e. it doesn’t specifically address big game harvest monitoring systems). Additionally, the paper was published in 2001, and there have been a number of advances in agency big game data monitoring and analysis techniques. Line 98/Study Area Section: Add description of other ungulates in Alberta, and if possible, relative abundance compared to elk. This would help the reader have some context when interpreting results relative to the predator effect. Lines 140-144: There’s nothing you can do at this point about the way the data were collected, but we know non-response can lead to bias in harvest data (i.e. non-response bias). As you point out, your real assumption here is that any non-response bias was roughly the same throughout the analysis period. I think that’s reasonable, especially given the alternative is to disregard the entire dataset! With that said, I recommend coming back and discussing your assumption in the Discussion. Specifically, I would emphasize that your results are not likely explained by some corresponding trend in non-response bias through time. Lines 167-170: I suggest deleting the sentences describing what happened to wolf populations prior to the analysis period. While interesting, it is not germane to the paper and seems misplaced. Line 241: Delete apostrophe from “Zone’s” Lines 271-273: You can say rather confidently that elk harvest has increased through the analysis period, but for the most part, you lack strong evidence to say that predator populations have increased over that period. I would reword to make that clear. Your main point still holds: that elk harvests (and almost certainly elk populations) have increased despite recovery of predator populations in recent decades. Also, I assume from your paper that sportsmen are concerned about effects of increasing predator populations on elk. Regardless of what predator populations are exactly doing, your dataset suggests that those concerns are not founded except in Zone 4. Line 298: Delete “of” after the word, “for”. Lines 317-330: I recommend deleting most of the management implications section. The references to other ungulates and apparent competition for the first time (in the management implications section) is confusing and misplaced. Are you suggesting that elk and possibly other ungulate populations should be reduced to enhance caribou populations (to reduce apparent competition)? Or are you saying that predator populations should be reduced to enhance caribou? None of this has been mentioned in the paper prior to this point or is even related to the objectives of the paper, and so it leads to confusion by bringing it up here. With that said, as I mentioned earlier, I do believe you should mention in the Study Area section that these other ungulates are present in Alberta, which will provide important context to your analysis. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0269407.r002
Revision 1
26 Aug 2022 Author Response Response to reviewer Thank you for the careful review of our manuscript. We offer the following responses to each comment: 1. We have followed guidelines carefully. 2. All data are freely available on line on the dataverse website, and a doi has been assigned: doi.org/10.5683/SP3/DINHMO 3. This map in Fig 1 is an original created by coauthor Andrea T. Morehouse and is available for use under the Creative Commons BY 4.0 License. We have inserted an attribution to Dr. Morehouse at the end of the figure caption. Detailed comments: Reviewer #1: I believe you did a nice job using existing data to address an important management issue that has implications for large mammal management across North America. Throughout large portions of western North America, concerns exist as to the effects of recovering predator populations on ungulate populations. You address this question as it pertains to predator and elk populations in Alberta. I like that you did not focus only on the area(s) where predator effects are hypothesized to be greatest (e.g., Zone 4 in your study), but instead looked at Alberta as a whole to provide a more complete picture. I made a number of edits below that I believe should be addressed prior to publication. Most important, please note my concerns below about the Management Implications section; I think you should remove references to other ungulates and apparent competition as this goes beyond the scope of the paper. Thank you for your constructive comments. We agree that reference to apparent competition is beyond the scope of our manuscript and we have deleted this material. Lines 26, 41: I believe elk scientific name changed to Cervus canadensis We disagree. The definitive reference for mammal taxonomy is the archived Smithsonian list of mammals and the Mammal species of the World by D. S. Wilson and D. M. Reeder. At the annual meeting of the American Society of Mammalogy I spoke directly with Dr. Wilson about the systematics of elk and he stands by explanation inserted in the Smithsonian list justifying that the latin binomial North American elk remains Cervus elaphus. Reference: Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Johns Hopkins University Press, 2,142 pp. Lines 29-32: I strongly suggest rewording these two sentences so it’s clear you are reporting rates of increase. When I first read the sentence on hunter success, I thought you were saying average hunter success was 0.2% or 0.3% per year (as opposed to increasing by that amount per year). I suggest rewording as: “Over a 26-yr period, average harvest of elk increased by 5.46% per year for unrestricted bull and by 6.64% per year for limited-quota seasons. Also, over the same time frame, average hunter success increased by 0.2% per year for unrestricted bull and by 0.3% per year for limited-quota seasons, but no trend was detected in hunter effort (P>0.05).” Thank you. We have accepted the wording change suggested by the reviewer. Lines 48-49: Be more specific with this statement or I suggest deleting it. Is this statement specific to Alberta, or Canadian provinces in general? If so, say as much. For many state agencies in the western US, analysis of harvest data is [sic] the basis for elk harvest management decisions. These analyses aren’t always published in the peer-reviewed literature, but they happen nonetheless, often by biometricians hired by the agencies to do that very thing. The cited paper (Yoccoz et al 2001) is not sufficient to support your statement (i.e. it doesn’t specifically address big game harvest monitoring systems). Additionally, the paper was published in 2001, and there have been a number of advances in agency big game data monitoring and analysis techniques. As recommended we have narrowed the scope of our statement to Alberta, and provided an updated reference in which Artelle (2019) conducted a systematic analysis of how science has been used for making wildlife policy decisions in North America. We have removed the Yoccoz et al. (2001) reference. Yes, there are state agencies that employ statisticians, but not most. We believe that our revised statement is correct. Line 98/Study Area Section: Add description of other ungulates in Alberta, and if possible, relative abundance compared to elk. This would help the reader have some context when interpreting results relative to the predator effect. Other hunted ungulates are now listed as recommended. We did not list mountain goats or bison because these 2 species are relatively uncommon and not hunted currently. Lines 140-144: There’s nothing you can do at this point about the way the data were collected, but we know non-response can lead to bias in harvest data (i.e. non-response bias). As you point out, your real assumption here is that any non-response bias was roughly the same throughout the analysis period. I think that’s reasonable, especially given the alternative is to disregard the entire dataset! With that said, I recommend coming back and discussing your assumption in the Discussion. Specifically, I would emphasize that your results are not likely explained by some corresponding trend in non-response bias through time. Thank you. We fully agree and have inserted a statement about sampling in the Discussion. Fortunately, harvest reporting is now mandatory and non-response bias should disappear as a possible bias. Lines 167-170: I suggest deleting the sentences describing what happened to wolf populations prior to the analysis period. While interesting, it is not germane to the paper and seems misplaced. We prefer to keep this material because it provides important context about the huge changes that have happened to large carnivore populations in Alberta during recent years. Wolves were essentially absent from elk ranges only 10 years prior to our analysis and they were still in recovery at the beginning of the period of our data. Similar changes have happened in many other areas of western Canada and USA. Line 241: Delete apostrophe from “Zone’s” Thank you, corrected. Lines 271-273: You can say rather confidently that elk harvest has increased through the analysis period, but for the most part, you lack strong evidence to say that predator populations have increased over that period. I would reword to make that clear. Your main point still holds: that elk harvests (and almost certainly elk populations) have increased despite recovery of predator populations in recent decades. Also, I assume from your paper that sportsmen are concerned about effects of increasing predator populations on elk. Regardless of what predator populations are exactly doing, your dataset suggests that those concerns are not founded except in Zone 4. The evidence for increasing populations of large carnivores is strong, but otherwise we agree with these comments. The reviewer clearly got our main message and we appreciate the perspective. Line 298: Delete “of” after the word, “for”. Thank you. Corrected. Lines 317-330: I recommend deleting most of the management implications section. The references to other ungulates and apparent competition for the first time (in the management implications section) is confusing and misplaced. Are you suggesting that elk and possibly other ungulate populations should be reduced to enhance caribou populations (to reduce apparent competition)? Or are you saying that predator populations should be reduced to enhance caribou? None of this has been mentioned in the paper prior to this point or is even related to the objectives of the paper, and so it leads to confusion by bringing it up here. With that said, as I mentioned earlier, I do believe you should mention in the Study Area section that these other ungulates are present in Alberta, which will provide important context to your analysis. As noted above, we agree that the apparent competition issue is beyond the scope of this paper so we have deleted relevant text and references. And as noted above we now list the other ungulates that are hunted in Alberta. Attachments Attachment Submitted filename: Response to reviewers.docx https://doi.org/10.1371/journal.pone.0269407.r003
14 Sep 2022 Decision Letter - Chad Bishop, Editor Sustainable elk harvests in Alberta with increasing predator populations PONE-D-22-14168R1 Dear Dr. Boyce, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. I participated as a reviewer for the initial evaluation of this manuscript. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Chad Bishop Guest Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0269407.r004
Formally Accepted
28 Sep 2022 Acceptance Letter - Chad Bishop, Editor PONE-D-22-14168R1 Sustainable elk harvests in Alberta with increasing predator populations Dear Dr. Boyce: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Chad Bishop Guest Editor PLOS ONE https://doi.org/10.1371/journal.pone.0269407.r005

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .