Thank you for sharing your manuscript „Citizen Science for Bat Research and Conservation“ with us. We acknowledge the relevance of this topic and appreciate the practical insights that the authors share with readers.
In our review, we focus on the social dimension of citizen science (CS) projects and especially on learning outcomes. We also have experience in conducting literature reviews. However, we have no expertise in bat monitoring methodology.
While we acknoledge the relevance of this timely review, we also have some concerns:
Our biggest concern is the lack of a definition or conceptual framework of CS that could have been the basis for the literature search. Without this definition the literature base for the review and its results are questionable. Other major concerns refer to the lack of detail in the Methods section and the Discussion section that needs further elaboration.

Introduction
In our assessment of the article's introduction, we believe that the relevance of a literature review on CS projects with bats should be strengthend by integrating ecological, virological and socio-political dimensions. Thereby, the introduction could more effectively highlight the threats facing bats and the central role of human actions in both driving decline and facilitating conservation.
Explain anthropogenic threaths: First, we would like the authors to emphasise how human activities directly contribute to bat mortality by providing a more detailed description (Lines 34-40). While the text touches on negative public perceptions of bats, it would benefit from expanding on specific anthropogenic threats that directly impact bat populations.
1. Collisions with wind turbines: While renewable energy sources like wind power are considered environmentally sustainable, they lead to high mortality rates in bats. Tens of thousands of bats die annually due to collisions with wind turbines, primarily due to rapid air pressure changes that cause barotrauma (Frick et al. 2017; Cryan and Barclay 2009).
2. White-nose syndrome: The fungal disease Pseudogymnoascus destructans, linked to human activity, has devastated bat colonies in North America. Mortality rates frequently exceed 90%, illustrating how introduced pathogens can wipe out entire populations within a few years (Barr et al. 2021).
3. Habitat loss and fragmentation: Urban expansion and agricultural intensification lead to the destruction and fragmentation of bat habitats, reducing roosting and foraging opportunities (Put et al. 2019).
4. Direct killing and persecution: Bats are still killed intentionally across various regions. In North America and Europe, bats were seen as nuisances and were killed, or as pest control (e.g. against vampire bats in South America), in response to fruit damage (e.g. Asia, Australia), or for consumption (e.g. Africa, Asia) (O’Shea et al. 2016).
These threats were further amplified during the COVID-19 pandemic. The suggestion that SARS-CoV-2 may have originated in bats fueled public fear, e.g. in China, leading to increased persecution and habitat disturbance. Although no systematic bat culling or mass killings have been documented (and there is no evidence of direct bat-to-human transmission of SARS-CoV-2), misinformation alone posed an additional threat to already vulnerable populations (Zhao 2020). Over half of all bat species worldwide have unknown or declining population trends, and fear-driven responses during the pandemic likely exacerbated this (IUCN 2020).
It is important to start by saying that bats do not carry more dangerous viruses than other mammals (Line 26). However, the fact that there are so many zoonotic viruses in bats can be explained by the fact that they have so many different species (more than 1,400; Simmons & Cirranello, 2020). This is similar to what we see in other groups of animals that are also very diverse, like rodents (Mollentze & Streicker, 2020). This misconception can lead to people blaming others for things that they have done. Additionally, bats are known to tolerate many viral infections without becoming ill themselves (Brook et al., 2020), suggesting unique immunological resilience that may have biomedical value.
Define CS and explicate possible challenges: Second, the authors should explain their understanding of the term “citizen science” and clarify which types of projects they consider to fall under this category. This term is the subject of much debate and there is no universal consensus of it in the scientific discourse. Yet, its definition determines which projects are included in this category. This clarity allows for a better understanding of why certain articles were excluded from the search and why others were included in the analysis. Furthermore, when writing about the benefits of participating in citizen science (Line 57), it essential to refer to Phillips et al. (2019). This paper provides a valuable framework for understanding and evaluating learning outcomes in citizen science projects, making it a key reference in the field.
In this line, we found the argumentation regarding the potential of CS projects involving bats to be rather one-sided. The authors merely cite the success of CS projects involving other species. What are the specific challenges that arise for CS projects involving bats, given the misconceptions that exist and practical considerations (e.g., nocturnal activity)?
Calibrate the focus of the review: The authors have opted for a systematic literature review to investigate their research questions that could also be a scoping review for two reasons: First, in our view, there is no explanation as to why the authors assume that the study situation is comprehensive enough to go beyond a scoping review. Second, the knowledge generated by the review is primarily descriptive in nature (with practical significance because it could inform other projects about what works). However, the review does not engage with critical appraisal of studies and it does not contribute to explaining why certain projects are more effective than others. The authors should reconsider the focus and scope of their review.

Methods
Overall, the methodology section requires major revisions, which is crucial for the study and subsequent analyses. The current methodology is poorly described and requires a more comprehensive account, including clear explanations of the screening process, how search terms were applied, and how data was extracted and categorized.
Critical Appraisal and Methodology: A systematic quantitative review also involves critically assessing the quality of the underlying studies. Otherwise, it is more of a scoping review. We did not find a critical appraisal of the studies that were included. The authors might want to consider either to critically appraise the studies or to follow the methodology of scoping reviews.
Explanation of the Screening Process: The screening process is not clearly explained. There is no information about inclusion and exclusion criteria or a flow chart showing the number of publications in the various steps of the review to make the review process more transparent. Furthermore, there is no information about the persons involved and how consistency was ensured during screening and data extraction. In this case, it is necessary to clarify the term ‚after screening‘ by explaining whether this refers to screening based on titles and abstracts, or whether full texts were also screened for eligibility.
Search Terms and Their Application: The stated limitation that volunteer-led projects may not have been included gives me some doubt. Could it be that the authors used the search terms too strictly? Perhaps a search for the string “volunt* AND monitoring” would have uncovered such publications. We think the authors should expand their search again and check how many studies they may have missed. This might yield more comprehensive results. As an example, the article by Wilson, C., & Godinho, L. (2013). The benefits of engaging volunteers in urban bat research. The Victorian Naturalist, 130(4), 182-187, which fits well within the scope of this review, was not captured, likely due to keyword limitations. Additionally, there is a suggestion to refine keyword selection by using synonyms commonly found in the literature, such as ‘community science’ or ‘public participation in science’. It is also important to specify the context in which the keywords were used, i.e. whether they were used to search for titles, abstracts and/or full-text databases.
Data Extraction and Categorization: Regarding the categorization of projects (Line 97), it would be helpful to know whether these categories were developed by the authors or derived from the literature. There are established frameworks in the field e.g., the typology by Bonney et al. (2009), which distinguishes between contributory, collaborative, and co-created, and the extension by Shirk et al. (2012), which includes contractual and collegial based on goals and roles; Line 107: For the data extraction process, it should be clarified who collected the data, and if done by multiple reviewers, how inter-rater reliability or consistency was ensured?

Results
To improve the robustness and clarity of the review, several key areas need to be addressed.
For the results of this review, a critical appraisal of the methods used in the studies is missing. This critical appraisal is one of the strength of a systematic review (and sets it apart from a scoping review) because readers can learn about the robustness of evidence. The results of the research question regarding scientific outcomes are not suitable for answering the question. The authors do not report the research results, but rather the research objectives. These results also lack a critical appraisal of the studies included in the review.
Accuracy and Clarity: In Line 114, the statement made is somewhat inaccurate and should be nuanced. Multiple analyses show a consistent rise in CS publications over the past 10–20 years, especially since 2010, indicating growing acceptance across disciplines (Pelacho et al. 2020; Bautista-Puig et al. 2019).
Numerical Consistency: In line 160, we count 53 rather than 51 as stated. Please double-check the numbers to ensure consistency.
Referencing Established Frameworks: In Line 162, the manuscript would benefit from referencing established categorization frameworks from the literature (see in line 97). Referring to typologies such as those would enhance conceptual clarity and position the analysis within the wider research discourse on citizen science.

Discussion
While we acknowledge that the discussion points are in principle productive and mostly substantiated by the findings, we feel that some of the conclusions either need substatiation because they are insufficiently developed or need elaboration because they are one-sided.
Discussion needs substantiation:
The issue of increasing numbers of CS publications (Line 183) has already been raised in an earlier comment. Please discuss whether this increase is new or whether it continues a previous development.
As mentioned in the comment for line 46, the manuscript does not provide a definition of CS, despite stating that it was clearly identified in the studies. This lack of a conceptual framework is problematic, particularly since there is no consensus. Studies (e.g. Haklay et al., 2021) have shown that even experts do not agree on what constitutes citizen science. To ensure clarity and scientific accuracy, it is essential to either include a definition or place the term within the broader scientific discourse (Line 246). Depending on the definition, the literature base of the review has to be extended.
The article (Whitehouse, 2024) does not make it entirely clear whether the study itself is a CS project in the strict sense (Line 284). In order to avoid conceptual ambiguities, it would be important for the authors either to clarify how this article corresponds to established definitions of citizen science, or to reconsider the use of the term in this context.
The authors should provide a source for their statement that not for profit organizations have expanded public participation (Line 197). Additionally, it would be helpful to provide evidence or references that support its validity to ensure the claim is accurately represented.
Discussion needs elaboration:
The discussion of geographic bias is highly relevant (Line 186). However, we would suggest emphasizing that such biases are not limited to CS projects on bats. Similar patterns can be observed across many scientific disciplines, where research is disproportionately concentrated in Europe and North America. The structural and systemic factors underlying these inequalities could be reflected.
The discussion on the prominence of universities in CS projects is too positive (Line 194). Other authors also discuss power imbalances and exploitative structures that can lead to the achievements of non-university researchers being recognized in publications. The authors should also discuss reasons that explain the challenges faced in citizen science projects.
In its current form, the argument for interdisciplinary collaboration appears overly simplistic and cannot stand on its own (Line 211). It fails to reflect the complexity and scope of the challenges associated with interdisciplinary work. To strengthen this argument, it would be beneficial to engage more directly with the specific difficulties that such collaborations face, such as different discursive norms and values (Harding, 1998), structural and methodological divergences (Stroupe & Carlone, 2021), and institutional constraints.
The argument presented in line 299 as a potentially effective solution cannot be accepted uncritically in its current form. Projects may prioritize the experience for volunteers over real conservation impact, sometimes resulting in ‘fictitious conservation’ where little actual benefit is delivered to the environment. Also the conservation becomes a spectacle for tourists, commodifying both nature and local labor, and often devaluing the knowledge and work of local communities (Brondo, 2015; Brondo, 2018). Or insufficient involvement of local stakeholders can reduce project sustainability and fail to address local needs (Ocañas & Thomsen 2023).

Style and Expression
NFP has not been introduced in the manuscript body. Figure 2 could be omitted because, all information are already in the text. Furthermore, using percentages is not informative if the population has less then 100.

I would like to thank the authors for the opportunity to review the revised manuscript. In my opinion, the time and effort invested has significantly improved the manuscript.

The authors now have appropriately framed the literature review as a scoping review. The ambiguities regarding the coding process have also been clarified. Although no evidence of the replicability of the coding procedure can be provided, the coding by one person appears to me to be at least consistent.

In the discussion, the authors have now considered further reasons for the geographical distribution of such projects and the surplus of institutional projects within the context of the depth of their results.

Our main criticism of the definition of citizen science has been largely addressed. However, the explanations (in the newly added paragraph of the Methods section) could also be understood to mean that the authors have recognized a citizen science project when they saw one. When was the interpretation of citizen science in a specific project appropriate for the scoping review and when was it too broad, resulting in the project being excluded? I understand that the authors could not base their project selection on a universal definition. They therefore resort to different definitions because their goal was to analyze "clearly defined citizen science projects in the comntext of bat research" (p. 42, ll. 149-150). I suggest that the authors at least cite some examples of different definitions of citizen science that formed the basis for the selected projects in order to increase transparency in the selection process.